Factors affecting utilization of phosphorus by poultry

MISSING IMAGE

Material Information

Title:
Factors affecting utilization of phosphorus by poultry
Physical Description:
viii, 119 leaves : ill. ; 28 cm.
Language:
English
Creator:
Waldroup, P. W ( Park William ), 1937-
Publication Date:

Subjects

Subjects / Keywords:
Phosphorus -- Physiological effect   ( lcsh )
Poultry -- Feeding and feeds   ( lcsh )
Animal Science thesis Ph. D
Dissertations, Academic -- Animal Science -- UF
Genre:
bibliography   ( marcgt )
non-fiction   ( marcgt )

Notes

Thesis:
Thesis (Ph. D.)--University of Florida, 1965.
Bibliography:
Bibliography: leaves 113-119.
Statement of Responsibility:
by Park William Waldroup.
General Note:
Typescript.
General Note:
Vita.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 000407586
oclc - 24681064
notis - ACF3891
sobekcm - AA00004946_00001
System ID:
AA00004946:00001

Full Text












FACTORS AFFECTING UTILIZATION OF

PHOSPHORUS BY POULTRY



















By
PARK WILLIAM WALDROUP










A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY











UNIVERSITY OF FLORIDA
April, 1965











,



AC:.C:C-.2DGE; E:'.7


The author is grateful to Dr. Robert H. Harms and Dr. C. B.

Ammerman for their assistance and guidance in planning and conducting

the research reported in this dissertation. Thanks are also given to

Dr. Lelvin Fried, Dr. R. L. Shirley, Dr. T. J. Cunha, and Prof. N. R.

Mehrhof for their aid and suggestions.

The aid of R. G. Combs and R. B. Cake is sincerely acknowledged,

and to them goes much credit for the performance of the experiments

reported herein.

The author is indebted to the Smith-Douglass Company, Norfolk,

Va., for a grant-in-aid which helped make these studies possible.

To his wife, Janet, he wishes to express gratitude for her help

and efforts on behalf of this dissertation.















TABLE OF CONTENTS




ACKNOWLEDGEMENTS . . ..

LIST OF TABLES . . .

LIST OF FIGURES . . ...


CHAPTER

1 INTRODUCTION . . ..

2 MATERIALS AND METHODS . .

3 THE INFLUENCE OF PHOSPHORUS LEVELS IN THE MkATERNAL
DIET .. .. .. ... . .

Experimental Procedure . ....
Results and Discussion .. .

4 CO.APISOU OF THE REQUIRE: lIJT$ OF BATTERY AND FLOOR
GRO"N CHICKS FOR CALCIUM AND PHOSPHORUS .....


Experimental Procedure
Results and Discussion

5 A CO:.TARISON OF PHOSPHORUS
CHICKS .*. .e. .

Experimental Procedure
Results and Discussion

6 THE UTILIZATION OF VARIOUS

Experimental Procedure .
Trial 1 .. ...
Trial 2 .

Results and Discussion
Trial 1 .......
Trial 2 .*. .


ASSAY TECHNIQUES WITH
0 9 0 9 9 0 9


* S 9
* 9 9

SOURZCS

* 9 9 9
* 9 9 9

* 9 9 9
* 9 9 9
* 9 9 9


9
*


OF CALCIUM .


* 9 9 9 9



*


Page

i

V

viii




1

h


6

6
9


14


21

22
24

29

30
30
33

33
33
36













TABLE OF CONTENTS-Continued


CHAPTER


7 THE EFFECT OF VITAMIN D ON PHOSPHORUS UTILIZATION .

The Interaction of Calcium, Phosphorus, and
Vitamin D .. ... .. .. .. .
Experimental Procedure .... ...
Results and Discussion ..

The Vitamin D Requirement of the Chick as Influenced
by the Dietary Calcium and Phosphorus Level .
Experimental Procedure ... ........ .
Battery brooder studies .. .* .
Floor pen studies . ...
Results and Discussion .. ...
Battery brooder studies . ..
Floor pen studies .. ...

8 THE AVAILABILITY OF PHOSPHORUS FROM ANl:AL PROTEIN
SOURCES .... . .

Experimental Procedure ............. .
Results and Discussion ........ *

9 THE AVAILABILITY OF PHOSPHORUS FROM PLANT SOURCES .

The Availability of Phytic Acid Phosphorus for
Chicks . . .. ..
Experimental Procedure ..........
Results and Discussion .. .. .


Comparison of Phytin Phosphorus Sources .
Experimental Procedure .
Trial 1 ...... .
Trial 2 .... .
Trial 3 .- .
Results and Discussion .
Trial 1 .............
Trial 2 ... .. .. ...
Trial 3 . .


Effect of Calcium and Vitamin D3 Levels on the
Utilization of Calcium Phytate .
Experimental Procedure *
Trial 1 ...... .. .
Trial 2 ..* *..... . ... .


iii


* 9 9 9 9

* 9 9 9 9

* 9 9 9 9
* 9 9 9 9
9 9 9 9 9
* 9 9 9 o
o o 9 9 9


Page











TABLE OF CONTENTS--Continued


CHAPTER Page


9 Results and Discussion .. .. 93
Trial 1 . ... 93
Trial 2 ................... 97

The Availability of Natural Plant Phosphorus 100
Experimental Procedure .. .. 100
Results and Discussion . 104

10 SMIARY AND CONCLUSIONS . 109

Phosphorus Levels in the IMaternal Diet 109
Variation Between Battery and Floor Conditions 110
Comparison of Assay Techniques .. 110
Source of Calcium ....... 110
Vitamin D Levels . 110O
Availability of Phosphorus from Animal Protein
Supplements ........... ll
Availability of Phosphorus from Plant Sources ill

R...RZ ECEz .. .. .. .. .. .. 113














LIST OF TABLES


Table Page

1 Composition of diets ................. 7

2 Hatchability and phosphorus and calcium content of
eggs when hens were fed diets with and without
supplemental inorganic phosphorus .. 10

3 Ash, phosphorus, and calcium content of the tibia
from day-old chicks hatched from hens fed diets
with and without supplemental inorganic phos-
phorus ... . 12

h Ash, phosphorus and calcium content of the tibia
from two week old chicks hatched from hens fed
diets with and without supplemental inorganic
phosphorus . . 13

5 Composition of basal diet . 15

6 Body weight and feed efficiency of chicks grown in
batteries and floor pens when fed diets containing
various levels of phosphorus and calcium (Trial l) 17

7 Body weight and bone ash of chicks grown in batteries
and floor pens when fed diets containing various
levels of phosphorus and calcium (Trial 2) *. 18

8 Composition of basal diet ........... 23

9 Body weight and tibia ash of 28-day old chicks fed
varying levels of phosphorus from two sources
under three regimens of calcium supplementation 25

10 Composition of basal diet ..........** 31

11 Analysis of calcium supplements .. 32

12 Bone ash of chicks grown on diets with different
calcium levels from various calcium supplements
(Trial l) ........... 34










LIST OF TABLES-Continued

Table Page

13 Body weights of chicks grown on diets with different
calcium levels from various calcium supplements
(Trial l) . . 35

14 Body weight of chicks fed diets with different
calcium levels from various calcium supplements
(Trial 2) . 0 37
15 Tibia ash of chicks fed diets with different calcium
levels from various calcium supplements (Trial 2) 38

16 Composition of basal diet ...... 0. 41

17 Body weight of chicks grown on diets varying in
levels of calcium, phosphorus, and vitamin D3 43

18 Percent of bone ash of chicks grown on diets varying
in levels of calcium, phosphorus, and vitamin D3 44

19 Composition of diets ..... 57

20 Body weight of chicks fed different levels of vitamin
D at different calcium and phosphorus levels
batteryy brooder studies) ........... *. 59

21 Tibia ash of chicks fed different levels of vitamin
D at different calcium and phosphorus levels
(attery brooder studies) .. 0 0 .. 60

22 Body weight of chicks fed different levels of vitamin
D3 at different dietary calcium levels (floor pen
study) .. .. .. .. 62

23 Tibia ash of chicks fed different levels of vitamin
D3 at different dietary calcium levels (floor pen
study) . . .. 63

24 Feed utilization of chicks fed different levels of
vitamin D3 at different dietary calcium levels
(floor pen study) ... *. 64

25 Analyses of animal protein sources ..... 68

26 Composition of basal diets ..... ....... 70











LIST OF TABLES-Continued


Table Page

27 Body weight of chicks fed diets supplemented with
phosphorus from animal proteins and inorganic
phosphate .* .# *. *. *# 72

28 Tibia ash of chicks fed diets supplemented with
phosphorus from animal proteins and inorganic
phosphate . 73

29 Composition of basal diets .. 77

30 Body weight and tibia ash of chicks fed various
levels of phosphorus from phytic acid and dicalcium
phosphate * 79

31 Composition of basal diet .......* .. 82

32 Body weight and tibia ash of chicks fed diets supple-
mented with various sources of organic and inorganic
phosphorus .. .. . 85

33 Body weight of chicks fed diets supplemented with
various sources of organic and inorganic phosphorus 87

34 Body weight of chicks fed diets supplemented with
various sources of organic and inorganic phosphorus 88

35 Body weight of chicks fed different phosphorus sources,
levels of vitamin D3, and calcium:phosphorus ratios 94

36 Tibia ash of chicks fed different phosphorus sources,
vitamin D3 levels, and calcium :phosphorus ratios 95

37 Body weight of chicks fed different phosphorus sources
with varying levels of calcium and vitamin D3 98

38 Phosphorus analysis of corn products . 101

39 Composition of. diets *. *.. 102

40 Body weight of broiler chicks fed diets with plant
phosphorus from three sources *. 105

41 Tibia ash of broiler chicks fed diets with plant
phosphorus from three sources .. 107


vii














LIST OF FIGURES


Figure Page

1 Bone ash and body weight of chicks receiving
various dietary phosphorus levels 47

2 Bone ash and body weight of chicks receiving
various calcium:phosphorus ratios .. 49

3 Bone ash and body weight of chicks receiving
various dietary levels of vitamin D3 .. 50

h Bone ash of chicks receiving various Ca:P ratios
with various phosphorus levels 51

5 Bone ash of chicks receiving various levels of
vitamin D3 with various calcium:phosphorus ratios 52

6 Bone ash of chicks receiving various levels of
vitamin D3 with various phosphorus levels 54


viii














CHAPTER 1


INTRODUCTION


The element phosphorus probably plays a more varied and important

role in the chemistry of living organisms than any other single element.

It iwas first prepared in the free state in 1669 by Brandt, a German

chemist, and first recognized as an essential constituent of bones by

Gahn, a Swedish chemist, in 1769. Subsequent research has demonstrated

that it is also an essential constituent of proteins and fats occurring

in muscular tissues and vital organs. Phosphorus has, by virtue of

its association with nucleic acids, been found to be an important part

of the structure of chromosomes. Phosphates are also known to be impor-

tant buffers in tissue fluids.

That animal rations may sometimes be deficient in mineral elements

began to be recognized in France and Germany about 100 years ago when weak

bones in cattle grazing in certain localities began to be associated with

mineral deficiencies in the soil. Ewing (1963), in tracing the history

of phosphorus in animal feeding, stated that in 1861 Van Gohren reported

that the ocurrence of weak bones in cows grazing in certain areas near

the Rhine River could be prevented and cured by feeding small amounts

of bone meal. Subsequent analyses of the soil and grass in these areas

revealed an abnormally low percentage of phosphorus and, to a lesser

extent, calcium. This report is the earliest recorded use of a phosphate


- 1 -






-2-


feed supplement for the specific purpose of preventing a phosphorus

deficiency disease in livestock, according to this reviewer.

The most abundant source of phosphorus for feed purposes is

rock phosphate. World reserves of 26 billion tons have been estimated,

about half of which is located in the United States. It began to be

used as a source of phosphorus in plant nutrition as early as 1860,

and fed to livestock in the United States about 1915. The danger of

fluorine toxicity in raw rock phosphate limited its use until 1914.0,

when defluorinated superphosphate was first produced on a commercial

scale. Many types of phosphates are now in use in animal feeds.

Numerous studies have been conducted to establish the phosphorus

requirement of the chick, with quite a variation in reported require-

ments. McGinnis et al. (l9L4) reported that levels of greater than

0.58 percent phosphorus were required for maximum calcification. Sing-

sen et al. (19h7) concluded that the available phosphorus requirement

for satisfactory calcification appeared to lie between 0.38 and O.h7

percent of the diet. Gillis et al. (1949) reported a requirement of

approximately 0.50 percent. This level was also suggested by O'Rourke

et al. (1952). Grau and Zweigart (1953) indicated that maximum tibia

ash of chicks was obtained with a level of not more than O.h5 percent

phosphorus.

Fisher et al. (1953) reported that chicks required 0.58 percent

total phosphorus for maximum calcification. Couch et al. (1937) sug-

gested that a level of 0.76 to 0.81 percent phosphorus was adequate for







-3-


normal growth and bone calcification of chicks up to twelve weeks of

age. Further studies are reviewed by Singsen et al. (1948), Gillis

et al. (1949) O'Rourke et al. (l952), and Nelson and Walker (1964).

A standard assay method for evaluating phosphorus compounds

is desirable in order to establish uniform values for each supplement.

However, considerable variation has been observed in the methods used

to test the utilization of the various phosphates. In certain assays

constant calcium to phosphorus ratios were employed (Creech et al.,

1956, Nelson and Peeler, 1961), while in others constant calcium levels

of 1.0 percent (Ammerman et al., 1960) or 1.2 percent (Gardiner et al.,

1959) were used. Similar variation has been observed in vitamin D

levels, supplementary phosphorus level, reference phosphate used, and

other factors.

The variability in these reports indicates the necessity for

a standard assay procedure for determining both the requirement of the

chick for phosphorus and the availability of phosphate supplements.

Therefore, studies were undertaken to determine factors which may

account for variation in phosphorus utilization by the chick in an

attempt to develop a standard assay procedure which would permit a more

accurate study of phosphorus in poultry diets.














CHAPTER 2


MATERIALS AND METHODS


The broiler chicks used in these studies were a Vantress x

7hite Plymouth Rock cross obtained from a commercial hatchery. At

one day of age the chicks were sexed, debeaked, vaccinated for New-

castle disease and infectious bronchitis, and randomly assigned to

treatment pens.

The battery brooders used in these studies were Cakes 801-A

five deck thermostatically controlled electrically heated battery

brooders with raised wire floors.

Two types of floor pen facilities were used. The first type

had pens 10 x 12 feet, equipped with 2 feed troughs, 4 feet in length,

and 1 bell-type automatic water fount. The second type had pens that

were 5 x 5 feet in size, each containing a tube-type feeder and a bell-

type automatic water fount. Infrared bulbs were used as the heat source

in both types of floor pens.

Chicks used for bone ash determinations were sacrificed at the

selected age and the right tibia removed. The bones were boiled for

3 minutes, cleaned of adhering tissue, and lightly polished with cheese-

cloth. After drying for 2h hours at 1000 C the bones were collectively

ether extracted and then ashed individually.






-5-



The data collected in these studies were subjected to the

analysis of variance as outlined by Snedecor (1957) ,,ith significant

differences between treatment means determined by use of the multiple

range test of Duncan (1955). Orthogonal components of variance were

determined following the procedure of Snedecor (1957).














CHAPTER 3


THE :!:DLU:::;.E OF PHOSPHORUS LEVELS IN THE MATERIAL DIET


Assay methods for certain nutrients in the diet of chicks

have been complicated to an extent by maternal influences. Variation

in the amount of the nutrient supplied in the diet of the dam often

influences the amount of this nutrient supplied in the egg to the

developing embryo. This is true for certain vitamins and antibiotics

and may also be true with inorganic nutrients. Therefore, variation

in the phosphorus level of the maternal diet could possibly affect

the results of phosphorus studies with young chicks, since most phos-

phorus studies are conducted with young chicks 3 to 4 weeks of age.

The objectives of this study were to determine the effect

of the phosphorus level in the breeder diet upon (1) the hatchability

of eggs (2) the mineral composition of the whole egg and the tibia

of the day-old chicks, and (3) the rate of bone mineralization of the

growing chick.


Expeeri-ntal Procedure


Two groups, each containing 5 commercial egg production type

hens, were fed on each of the basal diets shown in Table 1. Two

additional groups of 5 hens were fed each of the basal diets sup-

plemented with 0.35 percent phosphorus from feed grade defluorinated


-6-






-7-


TABLE 1


Composition of diets


Diet

Ingredient 1 2 3 h

(Percent of diet)
Yellow corn 37.10 32.10 65.60 59.90

Oats 30.00 29.20 .

Animal fat 4.70 4.70

Soybean meal (50% protein) 21.00 22.10 22.50 23.50

Alfalfa meal (17% protein) 5.00 5.00 5.00 5.00

Ground limestone 6.00 6.00 6.00 6.00

Iodized salt 0.h40 0.40 0.40 0.40

Micro-ingred ienu- 0.50 0.50 0.50 0.50


% Total P 0.39 0.39 0.34 0.34


1Supplies per pound of feed: 2,000 I.U. vitamin A, 700 I.C.U.
vitamin D3, 6 mcg. vitamin B12, 2 mg. riboflavin, 4 mg. calcium panto-
thenate, mg. niacin, 227 mg. choline chloride, 2.5 I.U. vitamin E,
0.08 gms. MnSO4 and 0.5 mg. menadione sodium bisulfite.






-8-


phosphate. The hens were maintained in individual wire cages and

given the experimental feeds and tap water ad libitum. Since the

composition of the diet did not affect hen performance or chick

measurements, only the effect of supplemental phosphorus will be dis-

cussed.

After the hens had received these diets for 7 months they were

inseminated twice each week with pooled semen from cockerels receiving

a complete breeder diet. All eggs produced for a 9-day-period were

incubated in order to determine hatchability. T'.o chicks franom each

hen were sacrificed at 1 day of age and the right tibia removed for

bone ash, calcium, and phosphorus determination.

All remaining chicks were wingbanded and placed in electrically

heated battery brooders and were fed the basal diet of Amnmerman et al.

(1961) with 0.2 percent supplemental phosphorus from defluorinated

phosphate. They were given the experimental diet and tap water ad

libitum. At 2 weeks of age all chicks were sacrificed and the right

tibia removed for bone ash, phosphorus, and calcium determination.

The total ash, phosphorus and calcium content of the fresh

egg were determined on 3 eggs from each hen immediately following the

collection period for the hatchability study. The eggs were crushed

and placed in a beaker, and the major portion of the moisture was

removed in a drying oven before they were transferred to a muffle

furnace for ashing.

The ash, calcium and phosphorus content of bones and eggs

w as determined by the procedures outlined by A.O.A.C. (1960).







-9-


Results and Discussion


Sunppl-m.ntin: the basal diets used in this experiment with

0.35 percent phosphorus, from defluorinated phosphate, significantly

increased hatchability of fertile eggs (Table 2). Although hatch-

ability of eggs was increased by the supplemental phosphorus, it did

not change the ash, phosphorus or calcium content of the fresh egg.

The observation that diets low in phosphorus resulted in low hatch-

ability without altering the percentage of phosphorus in the egg

agrees with data reported by O'Rourke et al. (1954).

The finding that 0.35 or 0.39 percent total phosphorus was

inadequate for normal hatchability does not agree with data of

O'Rourke et al. (1954), who found a phosphorus level of 0.30 or

0.35 percent was adequate for normal hatchability. This discrepancy

can be partially explained by the fact that the basal diet of O'Rourke

et al. (1954) contained only 0.19 percent total phosphorus, therefore,

it contained considerable supplemental inorganic phosphorus. The

basal diet employed in this study contained no supplemental inorganic

phosphorus. Since it is known that form of dietary phosphorus

(organic vs. inorganic) greatly influences its availability, the

difference in the type of phosphorus in the 2 basal diets could

account for the difference in results.

The ash content of the tibia or the phosphorus or calcium

content of the tibia of day-old or lh-day-olcd chicks was not in-

fluenced by the supplemental phosphorus in the maternal diet (Tables 3






- 10 -


TABLE 2

Hatchability and phosphorus and calcium content of eggs when hens
were fed diets with and without supplemental inorganic phosphorus



Egg Content1
% Supplemental % Hatchability EgCne
Phosphorus % Ash % P % Ca No. Eggs


0 47.1 8.U 0.191 3.48 120

0.35 68.72 8.67 0.189 3.56 120


IExpressed as a percentage of the fresh egg weight.

2This difference is statistically significant at the 0.01%
level of probability.






- 11 -


and h). The variation in tibia ash content from chicks within the

same hen group was as great as the variation in bone ash values for

chicks from different hens. Therefore, there would be no advantage

in selecting chicks from certain hens for phosphorus assays in an

attempt to decrease experimental error.

Supplemental phosphorus in the maternal diet did not appear

to alter the chick's ability to use calcium and phosphorus for

mineralization of the bone. Therefore, consideration of the phos-

phorus level of the maternal diet appears to be of limited value in

the selection of the chicks for the biological assay of phosphate.






- 12 -


TABLE 3

Ash, phosphorus, and calcium content of the tibia from day-old
chicks hatched from hens fed diets with and without
supplemental inorganic phosphorus



% Supplemental Tibia Content
Phosphorus
% Ash1 % p2 % Ca2 No. Analyzed

0 34.38 16.79 15.55 80

0.35 34.32 15.41 14.53 80


'Exoressed as a percentage of bone on a dry, fat-free basis.


2Expressed as a percentage of the tibia ash.











TABLE 4


Ash, phos:hcrus and calcium content of the tibia from two week old
chicks hatched from hens fed diets vRith and without
supplemental inorganic phosphorus



% Supplemental Tibia Content
Phosphorus
% AshI % p2 % Ca2 No. Analyzed

0 4o.81 19.00 41.98 59

0.35 l41.56 18.37 39.25 62

!Expressed as a percentage of bone on a dry, fat-free basis.
2Expressed as a percentage of the tibia ash.














CHAPTER 4


CC;'R._:30N OF THE REQUIREMENTS OF BATTERY AND
FLOOR GRO',T CHICKS FCP. CALCIUM AND PHOSPHORUS


It has recently been reported that the phosphorus requirement

is higher for laying hens maintained in cages than for those maintained

on litter in floor pens (Crowley et al., 1961; Harms et al., 1961;

Marr et al., 1961; and Singsen et al., 1961). It has been suggested

that hens on litter may be getting phosphorus from eating feces.

The calcium and phosphorus requirements of chicks were establish-

ed primarily from experiments carried out in batteries with raised wire

floors. Therefore, in view of the above mentioned reports it seemed

desirable to determine whether this difference in requirements existed

for battery and floor grom chicks.


Experimental Procedure


Two trials were conducted. In each trial day-old broiler chicks

were randomized into 30 groups of 5 males and 5 females, and 20 groups

of 50 males and 50 females. The 30 groups were randomly assigned to

electrically heated battery pens, with the 20 groups assigned to 10 x

12 foot pens with wood shavings used for litter.

The basal diet (Table 5) contained 22 percent protein, 1,000

Calories of productive energy per pound, 0.60 percent calcium and O.Li2


- 1h -







- 15 -


TABLE 5


Composition of basal diet


Ingredients Percent of diet


Yellow corn 59.08

Soybean meal (50% protein) 32.45

Animal fat 2.90

Alfalfa meal (17% protein) 3.00

Dicalciuim hshte O.42

Ground limestone 0.85

Iodized salt O.hO

Micro-ingredientsl 0.90


1Supplies per pound of feed: 2268 I.U. vitamin A, 10 mcg.
vitamin B12, 3h40 I.C.U. vitamin D, 2 rag. r :fvin, 9 mg. calcium
pantcthenate, 18 mg. niacin, 261 mg. choline chloride, 10 rag. terra-
mycin Hcl, 57 rag. santoquin, 80 rag. manganese sulfate, 35 rag. man-
gan.0os oxide, 9 rag. iron, 0.9 mg. copper, 90 mcg. cobalt, 5 mg.
iodine, 45 mcg. zinc, with 25 rag. nitrofurazane and 3.6 rag. furazoli-
done added to feed for chicks on floor.






- 16 -


percent total phosphorus. This diet was modified to form 9 other

experimental diets containing various levels of phosphorus and calcium

as shown in Tables 6 and 7. The desired levels of calcium and phos-

phorus were attained by varying the amount of ground limestone and

dicalciumn phosphate. Experimental diets were maintained iso-caloric

and iso-nitrogenous by varying the amount of yellow corn, soybean oil

meal and animal fat. Adjustments in energy and protein content of

diets were based on values of Titus (1955). Calcium and phosphorus

adjustments were based on chemical analysis of ingredients, and the

levels of these minerals determined in the mixed diets were in close

agreement with the predicted values.

Each of the 10 experimental diets was fed to 3 pens of chicks

in batteries and 2 pens on the floor in each trial. Experimental diets

and tap water were given ad libitum.

Chicks were individually weighed and feed consumption determined

at h weeks of age. Three males and 3 females from each floor pen and

2 males and 2 females from each battery pen were sacrificed at this

time in trial 2 for bone ash determination.


Results and Discussion


Results from these trials (Tables 6 and 7) indicate that the

requirement for calcium or phosphorus is similar for battery and floor

grown chicks. No significant interactions were found between calcium

or phosphorus and floor vs. battery grown chicks when measured by

28-day body weights or bone ash.






- 17 -


TABLE 6

Body weight and feed efficiency of chicks grown in batteries
and floor pens when fed diets containing various
levels of phosphorus and calcium (Trial l)


Diet 4-week body weight (grams) Feed/gain

% P % Ca Males Females Both Sexes

B1 F2 B F B F Av B F Av

0.48 0.60 428 406 370 380 399 393 396b 1.58 1.71 1.65

0.74 389 377 341 356 365 366 366a 1.58 1.76 1.67
0.88 379 374 342 341 360 358 359a 1.58 1.70 1.64

0.59 0.60 508 507 429 450 469 478 474de 1.53 1.64 1.59

0.74 488 501 448 429 468 465 466cd 1.52 1.63 1.58

0.88 490 492 411 437 451 464 458c 1.55 1.67 1.61

0.72 0.60 492 520 464 439 479 478 479de 1.55 1.66 1.61

0.74 509 520 414 451 462 485 474de 1.54 1.65 1.60

0.88 517 533 438 436 477 484 481e 1.55 1.67 1.61

1.10 516 530 444 437 480 483 482e 1.52 1.62 1.57

Average 472 476 410 416 441 445 "44 1.55 1.67 1.61


B indicates
F indicates


battery grown chicks.

floor grown chicks.


3Means having different superscripts are significantly

different (P= 0.05).







- 18 -


I
10 Cod c0 oIo o 'o ao M)




.. ., .
(X) co (n^ L- nr-i- ti r c^ [-
N < C\J 0 NC\\ 0 c\M-Z I\

x
0) LI c'-\ _34-3_-4 .4-3 43_ c3
00
CO 1-- (n)l\ \0 C* *S,\l^M _-j o *

0 m) n --Z _a --_t --'





u CN C \ON co \ 0Aooo\0 0


A A 14 00 14.; 00
*. 0 Z, H

CHC)
H C0



'o m 0 o* *
;q~C\CO 1\CJC: CQc\f%_t--
E- O-. H"I





0o C Q (n ", )\ H\ .


00 ce\ '-z _:: o --7x -o .
o. b o pq r o -.i" 1- 1 o- o




C HH H~ C\ Ac \








CCj .--i 0 0 0, H" C- -i ---I IS\ ON
0-i

4->~),c (nC '10 qa)o Is4-
*S-C' C-C' ON\JC\
00 ON ''&J \0(& i-vC (JOoOV\O V t







4' 00 0 00 \ #
al lr\ *~ -l re rCr~c -5_3__:t -- ":1 --7- 0y
cn cn m :t-Z-I-I









C. ad io o o0 oor a t o

E-4m c rnL- C.ZC~j C)" i0 "4 i
0 ~ ~ ~ ~ ~ ~ 3r g i Q C^ ~rI CCJT O










o M .b C

0 ri
:7 43pl A) m" C- coo0 H 00cX \0 -
H0 \0 C[-\ C\j c4A\ C\j c V\ A Cj V 0o C
KI-r ho i. IJC iI O Ji ^-r1 3V
*C)- tt

\01. v C\H^ H0lC^ \ r-OCOH r 4'




:T m 0I o-rCt -Z\JO3 --I -3-.I--1 to 0
Kf-O ON\Ori ^H0\ H~C


f4 f bq b


'0+' 1) ~-4-~4 "'.-~- ~ .4-4
Q0
to \ 0 I-Q r-I r-U t~iU-\ Q3 0 t b0


-P -.OC "O"\\ HH-4^t ON QI--3 H33 -3

I z I a H
r\-a CONON '0 *r- 'H
0o 't '0 0 \H






vi0 000 C\C H- C\j c'iONI-\Cj ~
4a m PQ C"\ _: _-:o O --0 CT ---I
j -:z 0\ "~ r m0~ O C\lV H H CeO\ ON r- 0 0


r>*3l- \0 c c n XN a,% 0\ IA 110 V- _:IV k 0- 4z 4

pq -- \, C\ oI co

u 11 ml co o\ r \0 cl- c^o \0 o\ c r~ ^\ J <
'!; C; Kl C C;



.14 1H






- 19 -


These data, indicating a similar requirement for calcium or

phosphorus by chicks grown either on wire or litter, are in direct

contrast to data reported for the laying hen under comparable conditions

(Crowley et al., 1961; Harms et al., 1961; Marr et al., 1961; and Sing-

sen et al., 1961). It is rather difficult to attempt to explain the

differential response between chicks and hens. Certainly these data

would not substantiate the hypothesis that very much phosphorus is

obtained from the feces. Although the phosphorus requirement determined

for hens maintained on wire does not appear to be the same for hens in

floor pens, this is apparently not the case for chicks.

The calcium X phosphorus interaction was highly significant

when measured by body weight in both experiments and by bone ash in

trial 2. This re-emphasizes the importance of the calcium-phosphorus

ratio when the diet contains a sub-optimal level of either of the

minerals, and agrees with recent data by Vandepopuliere et al. (1961),

and Simco and Stephenson (1961).

Under conditions of these experiments 0.59 percent total phos-

phorus in the diet of females was just adequate to support maximum

growth, but was not adequate for maximum bone ash (Tables 6 and 7).

A significant increase in growth rate and bone ash was obtained with

males when the total phosphorus content of the diet was increased

from 0.59 to 0.72 percent, resulting in a significant interaction of

sex X phosphorus. The interaction of sex and phosphorus has been

previously reported (Vandepopuliere et al., 1961) and re-emphasizes







- 20 -


the importance of considering sex when determining phosphorus require-

ment of chicks.

A level of 0.60 percent calcium appeared to be adequate to

support maximum growth in trial 1 (Table 6). However, males in

trial 1 receiving higher levels made numerically but not signifi-

cantly better growth. In trial 2 a significant improvement in

body weight and bone ash was obtained when the level of calcium was

increased from 0.60 to 0.72 percent (Table 7). Although there was a

trend for the males to give a greater response than females to in-

creased calcium, the interaction of calcium X sex was not statistical-

ly significant.

The calcium and phosphorus requirements of chicks as indicated

by these data are slightly higher than those reported by Simco and

Stephenson (1961). These workers used a different type of diet and

a different source of calcium and phosphorus which may account for

these differences in results.














CHAPTER 5


A COMPARISON OF PHOSPHORUS ASSAY TC IQU'ES WITH CHICKS


Studies have been conducted by many workers to establish the

comparative utilization of phosphorus from various supplements by

chicks. These reports are reviewed by Motzok et al. (l956) and

Hurwitz (1964). In general these studies are based on relating per-

centage of tibia, beak, or toe ash of chicks fed a test phosphate to

that of chicks fed a reference phosphate and establishing relative

biological values.

Considerable variation in the assay procedure employed has

existed. In certain assays constant calcium: phosphorus ratios were

employed (Creech et al., 1956; Nelson and Peeler, 1961), while in

others, constant calcium levels of 1 percent (Ammerman et al., 1960)

or 1.2 percent (Gardiner et al., 19$9) were used. Vandepopuliere

et al. (1961) found that it was essential to consider both phosphorus

level and Ca:P ratio when determining phosphorus availability. Nelson

and Peeler (1964) enumerated problems involved in the development of

a biological assay for feed phosphates. Among these was the question

of holding the calcium level constant or having a constant calcium:

phosphorus ratio in the assay diet.

Experiments were conducted to determine the influence of the

calcium content of the assay diet and the method of interpretation of


- 21 -






- 22 -


the data upon the relative availability of phosphorus from an inorganic

phosphate.


z;. er"r-ental Procedure


Feed grade dicalciuxn phosphate, generally considered to have

a high phosphorus availability, was compared to soft phosphate, general-

ly considered to be a less available source of phosphorus. Three regimens

of calcium supplementation were compared which included: (1) a constant

level of 1 percent Ca, (2) a constant Ca:P ratio of 2:1, and (3) a

"sliding" Ca:P ratio. The "sliding" ratios consisted of a different

Ca:P ratio for each level of phosphorus supplementation. Ratios were

selected which were considered to permit optimum performance of the

chick at each level of phosphorus supplementation.

Each of the phosphorus sources was added to the basal diet in

amounts adequate to supply 0.05, 0.10, 0.20 and 0.30 percent supple-

mental phosphorus. These phosphorus levels were fed in combination

with each of the 3 calcium regimens. The "sliding" Ca:P ratios used

with the phosphorus levels were as follows:

% Added ? Total Ca: Total P

0.05 1.2:1
0.10 1.h:1
0.20 1.6:1
0.30 1.8:1

A simplified degerminated corn-soybean meal diet was used as

the assay diet (Table 8). It was calculated to contain 22 percent

protein and 1000 Calories of productive energy per pound. Analysis






- 23 -


QTA L 8


Composition of basal diet



Ingredients Percent of diet


Degerminated corn meal 51.70

Cerelose 5.00

Soybean meal (50% protein) 3L.00

Alfalfa meal (20% protein) 3.00

Iodized salt 0.40

Micro-ingredientsl 0.90

Variable2 5.00

% Phosphorus 0.30

% Calcium 0.17


1Composition of micro-ingredients given in Table 5.

2Calcium and phosphorus levels were obtained by altering the
levels of ground limestone, dicalcium phosphate, soft phosphate, and
pulverized oat hulls.







- 2h -


indicated that the ingredients of the basal diet contributed 0.30

percent total phosphorus and 0.17 percent calcium. Desired calcium

and phosphorus levels were attained by variation of the test phos-

phates and ground limestone. Pulverized oat hulls were used to main-

tain the diets isocaloric.

Each experimental diet was fed to 3 pens of 5 males and 5

female broiler chicks in 2 successive trials, giving a total of 50

chicks per treatment. The experimental diets and tap water were con-

sumed ad libitum, beginning at one day of age.

At 28 days of age individual body weights were obtained. Two

chicks of each sex from each pen were sacrificed and the right tibia

removed for bone ash determination.


Results and Discussion


The type of calcium supplementation of the diet had a sig-

nificant effect on growth and bone calcification (Table 9). The use

of "sliding" Ca:P ratios resulted in significantly greater body weight

and tibia ash of chicks fed diets supplemented with either dicalcium

phosphate or soft phosphate, when compared to the use of 1 percent

calcium or a constant 2:1 Ca:P ratio. The use of a constant 2:1 ratio

promoted significantly greater weight gain and tibia ash for chicks

fed diets supplemented with dicalcium phosphate than did the use of

the constant 1 percent calcium. Use of the constant 2:1 Ca:P ratio

supported significantly greater weight gains than did the use of 1




















u\j
::::I,;
ft f




a tl






a ft ft e
a *0
C7\I









co coC 0 r-i
o c- A \ <^ A




0\ C Ci C~i
CO CMl 0 (MNO
CMj (n-.'-.Il m




*\ CD CO j ao
--3 \0 Cj 1>- 8
ON ON(n- CN 0
ON CMJ cc (y\j rQ










(3~ C; 8 C; z
H- 1>- ON'LUte






lAO0 00
* a a a
00001


00
00
r .
r--t i-t


%
"3
0 01;L
00 05
r4i r1 ->a4


* ft f tIf













: : : .: 4






CCM
ft ft ft fj at







0 -- 0%cr\j'
ft t t Fm~-T




V\ 0 0UM 0\
", I ",
















c MU\ C- C'o












-- 0co r-0 0(1)







0000
0 0 _3-0 c-t t,


0 -c0c' 0^lA
* a^ rar a^


0O0 k


ft* a ft ft




t ft a ft


* a
* a a


U)


cof


C\

~0
-H 0

4,+

o
0
'o
O0


)C oC
04



rn
'0





CH 0
0%0
(4-> )




(r) C\









co
,C3 .x::
0 I




tn0
0 \
o







,4-











r- 1
. .ol
) ON


u H




0 (a)










HP4,
+-o

















0
4-,

*n4
















0
cii r-4
* C', NO










0H








0
*H H

&0

0 l

*H '0



00






I'8


0 c(n- rzfm P











Go ONCj ~
E'- C) \0 0\K
(^\ c^' (^(^


'0

ir\\o H 3 ['e.












C)
COa (0J C') 10
r^co CM CM







0000





-H H



bfll





'0
*H


'U


RH
r-w-
0t w
4-4



00C-









to
0


0)


- 25 -






- 26 -


percent calcium in diets containing soft phosphate, but there was no

difference in percent tibia ash.

The comparative availability of the phosphorus from soft phos-

phate as compared to the phosphorus from feed grade dicalcium phosphate

was calculated using the tibia ash data in Table 9. Three methods of

determining the comparative availability were used. The first method

was that outlined by Nelson and Peeler (1961) in which the standard

curve was a regression line obtained by plotting the percentage bone

ash obtained at the various levels of added phosphorus againstthe

logarithm of the added phosphorus. The calculated comparative avail-

ability of phosphorus from soft phosphate was 58.9, 52.5, and 51.5

percent with 1 percent Ca, 2:1 Ca:P ratio, and the "sliding" Ca:P

ratio, respectively (Table 9). These values are greater than the 36

percent biological value reported by Nelson and Peeler (1961); however,

the standard use in their test was beta-tricalcium phosphate which was

of greater biological value than feed grade dicalcium phosphate.

The second method of determining comparative availability was

that outlined by Barauh et al. (1960) in which the percentage tibia

ash obtained with the test phosphate was divided by the percentage

tibia ash obtained with the standard phosphate. Using this method,

the comparative availability of the phosphorus from soft phosphate

was calculated to be 92.7, 92.h, and 93.3 percent at the 1 percent

calcium, 2:1 Ca:P ratio, and "sliding" ratio regimens, respectively

(Table 9). However, the validity of this method is questioned by

Nelson and Peeler (1961).






- 27 -


The third method used was that introduced by Combs (1955).

In this procedure, the slope of the response line of the test phosphate

(soft phosphate) was divided by the slope of the response line of the

standard phosphate (feed grade dicalcium phosphate). Comparative avail-

ability values obtained by this method were 57.5, 37.8, and 49.6 percent

for the 1 percent Ca, 2:1 Ca:P ratio, and "sliding" Ca:P ratio regimens,

respectively (Table 9). 17ith the exception of the value of 37.8 percent,

these values compare favorably v;ith those obtained using the method of

Nelson and Peeler (1961).

More recently, Hurwitz (196L) proposed a procedure for the

estimation of net phosphorus utilization on the basis of the phos-

phorus content of the tibia. This procedure offers another method

of calculating biological values for feed grade phosphates.

It is apparent from the present experiment that variation in

the procedure used to assay phosphate sources may greatly influence

the results. The type of calcium supplementation or method of in-

terpretation of the data may influence phosphorus utilization by the

chick. Therefore, standardization of phosphorus assay technique appears

to be desirable.

The use of different calcium levels or Ca:P ratios at different

levels of phosphorus supplementation appears desirable in order to elicit

maximum response of the chick and allow full utilization of the phos-

phorus. The variable Ca:P ratios selected for this study promoted

greater body weight and bone calcification than did the use of a fixed







28 -





Ca level or fixed Ca:P ratio but tended to give a lower apparent

biological value of the phosphorus from soft phosphorus.














CluAFT:it 6


.2 UTILIZATION OF VARIOUS SOURCES OF CA.LCDh2.:


Several sources of calcium are used in poultry feeding.

Experimental data indicate that the biological availability of cal-

cium from most of these sources is essentially equal. Buckner et

al. (1923) reported that limestone or oyster shell serve equally well

as sources of calcium for laying hens. The calcium in limestone,

=- ,n_, calcium gluconate, and dolomite were reported by Deobald et

al. (1936) to be equally available although differences in solubility

of the supplements were observed. Buckner et al. (1929) compared

calcium lactate, chloride, sulphate and carbonate and concluded that

the calcium carbonate was most effective for egg production as judged

by egg shell weight. Bethke et al. (1930) found no difference in- the

availability of calcium in the carbonate, sulfate, lactate, and phos-

phate salts or from limestone for bone formation in the growing chick

on equal calcium intake. Dougherty and Gossman (1923) reported that

limestone supported hi-her egg production than did oyster shell while

Kennard (1925) found oyster shell to be superior to limestone. More

recent reports indicate that calcium as calcium sulfate may be less

available than calcium as calcium carbonate as measured by its in-

hibitory effect on antibiotic absorption (Donovan et al., 1960).

Because of the effect of the dietary calcium:phcS;phorus ratio

on growth and bone development, especially when diets low in phosphorus


- 29 -







- 30 -


are fed, the availability of the calcium in the diet is of major importance.

Two trials were conducted to determine the availability to chicks of cal-

cium from sources available for commercial use.


Experimental Procedure


Trial 1.-Calcium sources tested were reagent calcium car-

bonate, reagent calcium sulfate, oyster shell, and ground limestone.

The oyster shell was pulverized prior to its use.

Graded levels of the calcium from the various sources were

added to a basal diet calculated to contain 20 percent protein and

1,000 kilocalories of productive energy (Table 10). This diet was

calculated to contain 0.60 percent total phosphorus. llonosodium

phosphate (NaH2Ph H20) was used as the source of phosphorus. The

basal diet was calculated to contain 0.17 percent calcium, all from

plant sources.

Samples of the calcium sources were submitted to a laboratory

for analysis. The calcium content as determined by this assay is

shown in Table 11. Using these values in column 1, each calcium source

was added to the basal diet in amounts sufficient to increase the total

calcium content of the diet to 0.2, 0.3, O.h, and 0.5 percent. This

resulted in 16 experimental treatments.

Three groups of 5 male and 5 female day-old, broiler type

chicks were assigned to each treatment. The chicks received the

experimental diets and tap water ad libitu1m from day-old until 28 days

of age. At this time individual body weights were obtained and 2 males






- 31 -


TABLE 10


Composition of basal diet



Ingredients Percent of diet


Yellow corn 52.02
Soybean meal (50% protein) 31.25

Animal fat 1.53

Alfalfa meal (17% protein) 3.00

Monosodium acid phosphate 0.90

Iodized salt 0 .0

Micro-in ire dient sl 0.90

Variable2 10. 00


1Composition of micro-ingredients given in Table 5.

2Consists of a calcium supplement, cerelose, and corn oil.






- 32 -


TABLE 11


Analysis of calcium supplements


Supplement Laboratory

A B C D

(0 Calcium)
CaCO3 (USP reagent) 40h.1 39.7 40.O 37.8

CaSO4 (US? reagent) 23.3 23.3 23.3

Ca Gluconate (USP reagent) 9.3

Ground limestone "A" 36.3 37.8 37.7 38.4

Ground limestone "B" 37.0 37.2 37.4

Ground oyster shell 39.2 38.4 37.5 35.0







- 33 -


and 2 females were sacrificed from each pen and the right tibia removed

for bone ash determination.

Trial 2.--The second trial was a close replicate of the first

with only minor changes. The lowest level of calcium tested in the

first trial was 0.2 percent, of which only 0.03 percent came from the

supplemental sources. Therefore, this level was eliminated from the

design and levels of 0.3, O.4, 0.5, 0.6 and 0.7 percent total calcium

were fed. The same basal diet and same calcium supplements as used

in the first experiment were used in the second experiment. In addition,

calcium gluconate was used at the 0.4. and 0.6 percent levels, and another

limestone source was used at all levels of calcium. This resulted in

27 experimental treatments. A similar number of chicks were assigned

per treatment and brooded as indicated in trial 1.


Results and Discussion


Trial 1.--The results of this trial indicated that the calcium

from the limestone supplement was more available than the calcium from

reagent calcium carbonate or sulfate or around oyster shell, as measured

by bone ash (Table 12). However, there was no significant difference

between the experimental groups as indicated by body ,eight at 28 days

of age (Table 13). It is felt that the increased bone ash value was

not meaningful since this was not repeated in the second trial. The

analytical value used in this trial for limestone "A" may have been

too low as indicated by analysis from other laboratories.






- 34 -


TABLE 12


Bone ash of chicks gro vn on diets with different calcium levels
from various calcium supplements (Trial l)


Dietary calcium (%)
Calcium Source Sex 0.2 0.3 0.4 0.5 Av

(% Bone ash)


Reagent CaCO3




Reagent CaSO4




Oyster shell




Limestone "A"





Average


26.7

27.9

27.3

27.4

29.1

28.3

26.8

29.2

28.0

29.2

28.4

28.8

27.5

28.7

28.1


29.8

32.9

31.4

29.5

32.2

30.8

30.1

32.2

31.1

31.3

32.6

31.9

30.2

32.5

31.3


33.3

33.5

33.5

33.4

35.5

3l4.5

33.7

34.3

34.o

3l4.8

36.4

35.6

33.8

34.9

34.4


35.6

37.9

36.8

35.5

35.7

35.6

36.3

36.6

36.5

38.0

37.5

37.8

36.4

36.9

36.6


31.5

33.1

32.3

31.4

33.2

32.3

31.7

33.1

32.4

33.3

33.7

35. 51


IDiffers significantly from other calcium sources (P= 0.05).






- 35 -


TABLE 13


Body weights of chicks grown on diets with different calcium levels
from various calcium supplements (Trial 1)


Dietary calcium (%)
Calcium Source Sex 0.2 0.3 0.h 0.5 Av


Reagent CaCO3




Reagent CaSO4




Oyster shell




Limestone "A"




Average


2146

214

230

220

222

221

221

199

210

254
193

2214

235

207

221


Body
352

315

334

344
334

339

356

3hO0

348

354

353

353

352

336

34)4


weight (gramins)
389 4h


357

373

42h

390

407

420

378

399

h34

399
416

417

381

399


40l
444



390

4l15

488


464

472

395

434

469

h09

439


366

324

345

357

334

3L6

371

339

355

378

335

357







- 36 -


increasing the calcium level of the diet significantly improved

body weight and increased the percent tibia ash of chicks (Cables 12

and 13). Male chickens were significantly heavier than female chicks,

but the females had a higher average percent tibia ash.

There was no calcium source X level interaction observed for

either body .weight or percent bone ash, indicating that each of the

supplements had essentially the same availability at all calcium

levels tested.

Trial 2.--No significant differences were observed between

any of the calcium supplements tested as measured by both body weight

and tibia ash (Tables 14 and 15).

Analysis of the data indicated that a level of 0.50 percent

total calcium was sufficient to support maximum body weight (Table la.),

but that 0.60 percent total calcium was re5:ui.:ed for maximum bone

calcification (Table 15) under the conditions of this experiment.

T..a body weight of males was significantly higher than that

of females (Table l). This effect was not altered by the calcium

level of the diet. Females tended to have a higher percent tibia ash

than did males (Table 15); however, this effect was significantly

altered by the calcium level of the diet. Females were able to tolerate

lower levels of calcium than were males as indicated by percent tibia

ash.






- 37 -


TABLE lh


Body weight of chicks
from various


fed diets with different calcium levels
calcium supplements (Trial 2)


Dietary calcium (%)
Calcium Sex 0.30 O.lO 0. 50 0.60 0.70 Averagel,2
Body weight (grams)3


P a ent
CaCO3


R~eant
CaSOL


Oyster



Limestone
"All


Limestone
"B"


Calcium
Gluconate


Average


376
372
3-hd

378
3L6
302d

362
357


h!l
361
3-id

392
368


* .
* .
* i

382
361
372a


h30
409
H20ef
hhh
399
Thef

458
4o4
173efg

h36
383
Zloe

4L2
4oi
4-21ef

4hh8
h02
]5efg

442
399
200b


h64
hlO
410
Wyg

472
415


478
417
Ugg

455

W331g
TTe
* 0


460
h413
Tylic


476
hoa

f g
h16o
LS0

486



39
h08
20e fg

458
396


L65
399
ITe-g

L66
4l07
137c


416

l56


398
O2Iefg

468
4!o
Tg^

453
4il
72Tefg

434
399
- efg


5* .5
* 0

*30
LUac


443
h03
723

L4o
393
ET7

1449
Lo




00
443
394


436
396


* 2
* *
* 0

LL2
397
420


'Does not include calcium gluconate groups.
2:leans do not differ significantly (P--0.05).

3M-eans with different superscripts are significantly different
according to Duncan's multiple range test (l9$55).







- 38 -


Tibia ash of chicks fed diets with different calcium levels
from various calcium supplements (Trial 2)


Dietary calcium (%)
Calcium Sex 0.3 0.4 0.5 0.6 007 Average1,2
Tibia ash (%)3


Reagent
CaCO3


Reagent
CaSO4


Oyster
Shell


Limestone
"A"


Limestone
T113 I


Calcium
Gluconate


Average


32.0
35.14
33.7e

32.5
33.9
jj^e

32.7
33.?
33.2l

33.3
34.1
T3-77
-3T.1
33.3
34.9
74-le

* .
* 9
* .

32.8
34.h
33-.a


35.3
37.6
30--. 2
36.2
36.9


35.5
37.1
3o.3 f

35.6
37.2
36.67
36.6
3-76f g

35.8
37.9
36-.f

35.8
37.1
3-3b


37.1
38.5
`7. fgh

37.8
38.7


37.7
39.6


37.2
37.5
-3f gh


37.6
38.3


* -
a

37.5
38-5
*-.- --


38.14
39.5


38.2
38.6


39.4
38.7
39.0ij

38.7
39.3
-T8-. J


38.5
38.6


37.3
h.O.2


38.6
38.9
To. Iq


37.8
39.0


37.3
39.6
3.71n ii

39.2
40.7
39.9J

39.2
38.8
3ij

38.8
38.7


T .
* 9

38.5
39.h
'3


76.1
38.0
37.1

36.4
37.5
36.9

36.9
37.9
37.43

36.8
37.0


36.9
37.4
37.2

* .
. 4

36.6
37.6
T771 i


'Does not include calcium gluconate groups.
2?reans do not differ significantly (P=O.05).

3Means with different superscripts are significantly different
according to Duncan's multiple range test (1955).














CHAPTER 7


:- EFFECT CF VITW'T"_ D ON P:-"-"?-:?S UT?:.: ':".:


1Jithin the past few years much attention has been directed

toward a re-evaluation of the phosphorus requirements of chicks

(Simco and Stephenson, 1961; Lillie et al., 1961; Formica et al.,

1961; Vandepopuliere et al., 1961). However, varying results have

been reported. A part of the variability in the results obtained

may have been due to the inter-relationship in the diet of calcium,

phosphorus, and vitamin D, which has long been known to be important

for satisfactory growth and bone development (Bethke et al., 1928;

Hart et al., 1930; Wilgus, 1931; .cC:-e.y and Giacomino, 1945;

Carver et al., 1946; Migicovsky and Emslie, 1947). To gain additional

information about the inter-relationship of these factors, experiments

were conducted to determine the effects of various calcium:phosphorus

ratios and levels of vitamin D3 on the utilization of phosphorus by

broiler-type chicks.


The Interaction of Calcium, Phosphorus, and Vitamin D


Experimental Procedure

Two trials were conducted to evaluate the degree of inter-

action existing between the vitamin D, calcium and phosphorus levels

in the diet of chicks. The design of the 2 trials involved a 3X3X3


- 39 -







- 40 -


factorial arrangement of treatments, with 3 calcium:phosphorus ratios

(1:1, 1.4:1, and 1.8:1), 3 levels of phosphorus (O.48, 0.59, and 0.70

percent total phosphorus), and 3 levels of vitamin D3. The vitamin D3

levels were altered for the 2 trials, with i5, 90, and 180 i.C.U./lb.

of diet being used in the first and 90, 180, and 360 I.C.U./lb. being

used in the second.

The composition of the basal diet used in this experiment is

shown in Table 16. By analysis, the basal diet supplied 0.39 percent

phosphorus, all as organic phosphorus. Reagent grade calcium carbonate

and monosodium phosphate (NaH2PO.4 H20) were used to supply the desired

levels of calcium and phosphorus. A commercial source of vitamin D3

(200,000 USP units per gram guaranteed) was obtained and the potency

determined by the average of 3 independent laboratory reports using

different analytical techniques (233,000 I.C.U. per gram). Cerelose

and corn oil were used to keep the diets iso-caloric. Samples of the

diet were assayed for calcium and phosphorus, and the results were in

close agreement with calculated values. The basal diet for all treatments,

with the exception of the variable ingredients, was mixed in a single batch,

and aliquot parts were used for each experimental diet. The diets were

mixed the day before the trial began and stored at 55 F. until fed.

Day-old broiler chicks were randomly assigned into groups of 5

male and 5 female chicks, and placed in battery brooders. Three groups

were assigned to each treatment. The experimental diets and tap water

were given ad libitum. All sources of ultra-violet light were eliminated

from the battery room.






- hi -


TABLE 16


Composition of basal diet



Ingredient Percent of diet


Yellow corn 50.0

Soybean meal (50% protein) 3h.O

Animal fat 1.7

Alfalfa meal (17% protein) 3.0

Iodized salt O.h
-icro-ingredientsl 0.9

Variables2 10.0


2-Cc i-'. tin of micro-ingredients given in Table 5 with
removal of vitamin D.

2Variable ingredients included reagent CaC03, NaH2POh H20
and corn oil.







- 42 -


At 28 days of age the chicks were individually v.ei-hed, and

the experiments terminated. Feed consumption per group was determined,

and feed conversion was calculated. Two males and 2 females from each

group were sacrificed for bone ash determination.


Results and Discussion

Increasing the level of phosphorus in the diet from O.48 to

0.70 percent resulted in a highly significant increase in average body

weight (Table 17) and percent bone ash (Table 18). These effects were

best fitted by quadratic equations, indicating that the optimum phos-

phorus level had been reached.

Widening the calcium:phosphorus ratio of the diet from 1:1 to

1.h4:1 significantly increased body weight and percent bone ash (Tables

17 and 18). A further increase to a 1.8:l ratio did not affect body

weight but lowered the percent bone ash; however, this reduction was

not statistically significant.

A highly significant increase in body weight and bone ash was

observed when the vitamin D3 level of the diet increased from h5 I.C.U.

to 180 I.C.U. per pound (Tables 17 and 18). This increase was linear,

indicating that higher levels of vitamin D3 were beneficial, and pro-

moted the change in levels for the second trial.

Several interactions between the factors were observed. The

interaction of Ca:P ration X phosphorus level of the diet was highly

significant for both body weight and bone ash (Tables 17 and 18).

Vitamin D3 levels and Ca:P ratios also interacted in a significant






- 143 -


TABLE 17

Body weight of chicks ;'z.r:- on diets varying in levels of
calcium, nhzc-.c.rus, and vitamin D3


Vt. D % Phosohorus
Vit-. D_______;_______
Ca:P Ratio I.C.U./!b. O.L8 0.59 0.70 Average


1:1 L5 204 249 260 238
90 256 299 3h9 295
180 360 384 416 387
360 JK3 120 424 409
Av 30 33 32 33O-2

1.4: 45 256 329 37h 319
90 314 396 395 368
180 328 395 416 379
360 355 uO8 392 385
Av 31B 335

1.8:! 45 259 363 399 310
90 291 376 405 357
180 311 17 372
360 314 367 396 359
Av 29,4 3'7
Average 45 239 3114 344 299
90 287 357 383 340
180 333 398 416 379
360 350 398 404 384
Av 302 35 7 371







- u4 -


TA3mS 18


Percent bone ash of chicks ^.':-j
calcium, ohcs ru,


on diets varying in levels of
and vitamin D3


Vit. D. % Phosphorus
Ca:? Ratio I.C.U./lb. 0.48 0.59 0.70 Average


l.4:1


245
90
180
360
Av

L5
90
180
360
Av

45
90
180
360
Av

45
90
180
360
Av


1.8:1


Average


29.0
29.4
33.9
37.3
32.)T

27.4
29.0
31.4
33.0
30.2

26.7
26.9
28.4
29.4
27.d

27.7
28.4
31.2
33.4
30.2


28.8
32.3
37.5
39.5


32.1
37.3
39.0
h4o.5
37.2

34.5
3O.7
38.-4
38.3
37.0

31.8
35.h
38.h
39.5
36.3


31.3
34.9
39.6

369,

37.0
39.6
42.0
43.2


39.2
40.3
242.6
2o.8
1740.7

35.8
38.3
439.2
241,24
39.2


29.7
32..2
37.0
39.0
31.3

32.2
35.3
37.5
38.9


33.5
324.6
36.5
36.2
35.2

31.8
34.1
37.0
38.1
35.3






- 45 -


manner for both of these criteria. The interaction of phosphorus levels

and vitamin D levels of the diet was si'.-'i'icant for body weights but

not for cyrc-c.nt bone ash (Table 17 and 168). No interaction of the three

major factors, Ca:? ratio, vitamin D and phosphorus levels was observed

for either body weight or bone ash.

.,ales had greater body weights than did females, but in :en,-ral

the females had a higher percent bone ash. Lo:,er requirements for

mineralization by females w."ere indicated by sex X Ca:P ratio and sex X

vitamin D3 level interactions.

Th; second trial was almost identical with the first, havi .:

the same phosphorus levels and Ca:P ratios but increased vitamin D3

levels. Therefore, similar results were expected. Both body w:2i.ht

and percent bone ash were significantly increased when the phosphorus

level of the diet was increased from 0.48 to 0.70 percent (Tables 17

and 18). These effects were best described as fitting a quadratic

equation, indicating that an optimum level w..as reached.

A calcium:phosphorus ratio of 1.4:1l did not increase body weights

ihen compared to the 1:1 ratio, but increased the percent bone ash (Tables

17 and 18). A further spread of the Ca:P ratio to 1.8:1 lowered both

body weight and bone ash.

Increased levels of vitamin D resulted in increased body weight

and percent bone ash (Tables 17 and 18). The response of body weight

was best described as a quadratic effect, while percent bone ash assumed

a linear effect.







- 46 -


The interaction of Ca:P ratio X phosphorus level of the diet

remained highly si-r.ificant for both body -,eight and percent bone ash

(Tables 17 and 18). Ca:P ratios and vitamin D3 levels also interacted

in a highly significant manner for these criteria. A significant inter-

action of phos7)ho:-us X vitamin D level was observed for both criteria.

A significant phosphorus X Ca:P ratio X vitamin D interaction occurred

with body weight, but not with percent bone ash (Tables 17 and 18).

As in the first trial, females weighed less but in general had

a greater percent bone ash.

Analysis of the data showed that the treatment groups common

to both trials 1 and 2 (those diets containing 90 and 180 I.C.U./lb.

of vitamin D3) were true replicates. Therefore, the results of the 2

trials were combined for discussion.

The response to increasing the phosphorus level of the diet

from O.48 to 0.70 percent indicated that the optimum phosphorus level

for both body weight and bone ash was between 0.59 and 0.70 percent of

the diet (Figure 1). This appeared to be true for both sexes, since

there was no sex X phosphorus interaction.

Interpolation of the data in Figure 1 indicates that the phos-

phorus requirement is approximately 0.6L percent. This agrees closely

-with recent york using similar basal diets and experimental conditions

(Vandepopuliere et al., 1961). The response in body weight closely

paralleled that of bone ash.

Calcium:Dphosphorus ratios of 1:1 significantly depressed both

body weight and percent of bone ash when compared to the 1.4:1 ratio,









- 47 -


40



38



36


34
W
I&J
0
0
8132



30


0.48 0.59 0.70

% PHOSPHORUS


400


E


I-


0
>-
w
m


a5
500


FIGURE 1



Bone ash and body weight of chicks receiving
various dietary phosphorus levels






- 18 -


over all levels of phosphorus and vitamin D3 (Figure 2).

The response to increased levels of vitamin D3 in these t-sts

indicated that 180 I.C.U./lb. was adequate for maxi um body weight but

that 360 i.C.U./lb. further increased the percent bone ash (Figure 3).

Tibia ash appeared to be a more sensitive criterion than body

eightt for studying the adequacy of the calcium, phosphorus, and

vitamin D3 levels of the diet. The-'efore, this measurement is used

to illustrate the interaction that occurred in these experiments.

The interaction of Ca:P ratios and phosphorus levels is illus-

trated in Figure h. At 0.38 percent phosphorus, a sub-optimal level,

Ca:P ratios of l.4:l and 1.8:1 significantly depressed the percent

bone ash, as compared to the 1:1 ratio. As the level of phosphorus

more closely approached the requirement, between 0.59 and 0.70 percent,

the wider ratios resulted in increased tibia ash, indicating a greater

tolerance and in fact a necessity for increased ratios as the level of

phosphorus increases.

A primary function of vitamin D has been shown to be the enhance-

ment of calcium absorption of the intestinal tract (V'asserman et al.,

1957; Greenberg, 1945). Figure 5 illustrates this effect and indicates

that the response to the increased vitamin D, levels decreased as the

Ca:? ratio widened. At the lower Ca:P ratios the calcium level w:as no

doubt sub-opt -al, even t'..CL-h the phosphorus level m.,n- have been adequate.

As the ratio widened, more calcium vwas present, and the response to the

increased levels of vitamin D3 vwas less.






- 49 -


BODY WEIGHT


CALCIUM: PHOSPHORUS


18:1


RATIO


FIGURE 2


Bone ash and body weight of chicks receiving
various calcium:phosphorus ratios


X36
W
<(

z
034
0

32



30


320
340 a

a

3202








- 50 -


40



38



36


X
34

L&J
w
z
0
S32



30



28


40



380



360
W4O


E
340 2



320 w


8
300 C



280


90 180
VITAMIN D Icu/Ib


FIGURE 3



Bone ash and body weight of chicks receiving various
dietary levels of vitamin D3







-51 -


421


0.48 0.59 0.70
% PHOSPHORUS










FIGURE 4


Bone ash of chicks receiving various Ca:P ratios
with various phosphorus levels







- 52 -


42


40
360 Icu

3m
ICU~

36



34
W
Z 32
0


30



28


26 __________
: L41 11:1
CALCIUM., PHOSPHORUS RATIO













FIGURE 5



Bone ash of chicks receiving various levels of vitamin D3
with various calcium:phosphorus ratios






- 53 -


Although studies by Cohn and Greenberg (1939) indicated that

vitamin D did not enhance phosphate absorption in rats reared on a

vitamin D deficient, high calcium--low phosphorus diet, an interaction

of vitamin D3 and phosphorus level was noted in this exreriTr.cnt. Figure

6 indicates that as the level of phosphorus more closely approached the

requirement, between 0.59 and 0.70 percent of the diet, the response to

the increased vitamin D3 deviated from a linear to a quadratic effect.

Rather than being an effect of the vitamin D3 on phosphorus utilization

per se (an actual vitamin D3 X phosphorus interaction), this response

may merely reflect a vitamin D3 effect on the increased calcium levels

occurring as the phosphorus level increased, since the calcium is

present as a ratio of the phosphorus and not as a constant level. This

-'a-.h also indicates that at sub-optimal levels of vitamin D the phos-

phorus requirement may be in excess of 0.70 percent, as indicated by

the linear response of the 15 I.C.U./lb. level of vitamin D3.

No significant interaction of Ca:P ratios and vitamin D3 and

phosphorus levels was observed when the data were combined from the 2

experiments. This was true for both bone ash and body weights. How-

ever, certain trends were evident, and definite observations can be

made concernLing the over-all interaction of this triumvirate. Tideninr,

the calcium:phosphorus ratios at sub-optimal levels of phosphorus result-

ed in decreasing the body weight or percent bone ash. Chicks tolerated

the wider ratios more effectively with increased levels of vitamin D3,

up to 360 I.C.U./lb. in these tests.






- 54 -


434

B- 32


/


048 0.59 0.70
% PHOSPHORUS


FIGURE 6

Bone ash of chicks receiving various levels of vitamin D3
with various phosphorus levels






- 55 -


As the level of phosphorus increased, wider calcium:phosphorus

ratios were tolerated or in fact desirable. This may be due not only

to the actual calcium:phosphorus ratio but also to the total amount of

calcium and phosphorus present. The response to increased vitamin D3

became less as calcium and phosphorus levels approached the optimum.


The Vitamin D Requirement of the Chick as Influenced by
the Dietary Calcium and Phosphorus Level


Results of the previous experiment indicated that dietary

vitamin D3 levels of 360 I.C.U. per pound increased body weight and

percent bone ash of chicks. However, the response to hig-.er levels of

this vitamin became less as calcium and phosphorus levels approached

optimum. To gain additional information re xr.ing the effect of in-

creased vitamin D3 levels and the relationship of this vitamin to the

calcium and phosphorus content of the diet, feeding trials were con-

ducted under conditions of practical-type rearing as -well as in battery

brooders isolated from sources of ultraviolet light.


Expcerimental Procedure

Battery brooder studies.--A factorial ari'ar.-e-ment with 2 calcium

levels (0.50 and 1.00 percent), 2 phosphorus levels (0.50 and 0.70 per-

cent total phosphorus) and 7 levels of vitam.:" D3 was used. Levels of

vitamin D3 compared were h5, 90, 180, 360, 720, 36,0 and 7200 I.C.U.

per pound of feed. This resulted in diets whi.h :e e (1l) adequate in

both calcium and phosphorus, (2) adequate in calcium with sub-o-otimal







- 56 -


phosphorus, (3) sub-optimal calcium with adequate phosphorus, and (4)

sub-optimal in both calcium and phosphorus.

Three pens of 5 male and 5 female day-old broiler chicks were

randomly assigned to each dietary treatment in 2 successive trials,

,lvi a total of 60 chicks per treatment, placed in battery brooders.

All sources of ultraviolet light were eliminated from the experimental

room.

-'he composition of the basal diet is given in Table 19. Desired

levels of calcium and phosphorus were attained by a variation in the

level of reagent grade calcium carbonate and reagent grade monosodium

'h. rte (Na2P. H20). Sand was used as a non-nutritive filler to

keep enery and protein levels constant. The vitamin D3 supplement was

dcdzii] -in the previous experiment. The diets were mixed 2 days prior

to the beginning_, of each experiment and stored at 55 F. until fed. T.e

experimental diets and tap water were fed ad libitum. At 28 dys of age

individual bzdy weights were obtained. T.o males and 2 female chicks

froi each pen were sacrificed for bone ash determination.

Floor pen studies.--To study the vitamin D3 requirement of the

broiler chick under conditions usually encountered in commercial flocks,

a trial was conducted in floor pens in a broiler house in which no

attempt was made to exclude sources of natural light. The house con-

tained 4 rows of pens, 2 of which were along the outer wall with 2 inner

rows. Four replicate pens of 10 male and 10 female chicks were aszimed

to each dietary treatment with the restriction that a pen from each of

the 4 rows be used. The pens were 5 x 5 feet in size.







- 57 -


TABLE 19

Composition of diets


Floor
Ingredients Battery
1 2 3

Percent of diet
Yellow corn meal 51.70 56.08 56.08 56.08

Soybean meal (50% protein) 34.00 34.00 34.00 34.0Oo

Dehydrated alfalfa meal
(20% protein) 3.00 3.00 3.00 3.00
Ground limestone 0.22 0.75 1.27

Dicalciun phosphate 1.35 1.35 / 1.35

Animal fat 3.00 3.00 3.00

Iodized salt 0.40 0.40 0.140 0.140

Micro-ingredientsl 0.90 0.90 0.90 0.90
Variable2 10.00 .. .

Sand 1.05 0.52 .

% Protein 22.4 22.6 22.6 22.6
Productive energy
(Cal.Ab.) 928 981 981 981
% Calcium2 0.60 0.80 1.00
% Phosphorus2 0.65 0.65 0.65

IAs outlined in Table 5 with removal of vitamin D.
2Calcium and phosphorus levels were adjusted by altering the
level of variable ingredients consisting of calcium carbonate, mono-
sodium phosphate, yellow corn and sand.







- 58 -


A 3 X 6 factorial arrangement of treatments was used. This

consisted of calcium levels of 0.60, 0.80, and 1.00 percent with a

vitamin D3 level of 45, 90, 180, 360, 720, and 3600 I.C.U. per pound.

All diets contained 0.65 percent total phosphorus and were iso-caloric

and iso-nitrogenous. The composition of the diets containing the three

calcium levels is shown in Table 19. The vitamin D3 supplement used in

the battery brooder trials was used to supply the desired levels of this

vitamin.

Body weight and feed consumption were determined at 8 weeks of

age. Two male and 2 female chicks from each pen were sacrificed for

determination of bone ash.


Results and Discussion

Battery brooder studies.-The vitamin D3 requirement of the chicks

used in these studies was highly dependent upon the calcium and phosphorus

level of the diet. With levels of 1.00 percent calcium and 0.70 percent

phosphorus, maximum body weight and bone ash were obtained with 90 I.C.U.

of vitamin D3 per pound (Tables 20 and 21). This is in agreement with

the vitamin D3 requirement as suggested by the National Research Council

(1960). When levels of calcium or phosphorus were sub-optimal, the need

for higher vitamin D3 levels was observed. With a dietary calcium level

of 1.00 percent and a total phosphorus level of 0.50 percent, 3600 I.C.U.

of vitamin 1)3 per pound -was, needed for optimum body weight and bone ash.

At a dietary calcium level of 0.50 percent, 720 I.C.U. of vitamin D3 per

pound was required for maximum body weight and bone ash at both phosphorus

levels.































.v3 .c


r vl i i>hf



'-* O' CM




fe-.








-14, 0

o ~
Hg -4 c






4x, en
-4 (l%


*r4 r)
~
Cu C-
lA C--
-~ -4


1-4 -4i


IL
0





0
4-1
04
4H





.0




%-0
4o




040
0
-Pl
fir







00
0


W 0

4-H






(1)Q


0 V
0}+


0



0


U)
t4














r.

C)








m
U)0













o
U)


U)
































4) 4-
4A








0




a
0






V


G2
0
























'U
0
0
0







00


U)






0


0
10


-59 -









-60 -


4'

0
'4
0


'0





04-*
102












00
4C
4'






0 +
OH0


H
a,
0 H


'0 02







00
02





Cd
00



'a>





--i
-0


C-

*
fan


'.-






44










CN
J0
'0






A
*5*
P.-'
CE'




0^
N

CE'


0s
H



0^
H**






0
*
0M


UVA m^
*
v0 '.0

CV

0 0
*~ H









0 0
*O 0



a: c^
; 9
'.0 CO


0

e-

*Z A
.0 .0




Ho tco

0






cO C-
*v\ f

bCi *r4
0






*^ *




S


N
i

! I
CMj
















V
4-1













0
aO


















0,0
0
>M












4-7
0


S*








.0











to
a,


02+








GO r.

0 H
.% 4'








a0




0 02

H
04
Q>
-I


-P0


CM4









0
N















0







-61 -


Floor pen studies.-The 56-day body weight and tibia ash of the

chicks were significantly affected by the dietary calcium and vitamin D3

levels (Tables 22 and 23). There was a significant interaction observed

between the dietary calcium level and the vitamin D3 level. At 0.60

percent calcium, 360 I.C.U. of vitamin D3 per pound gave significantly

maximum body weight and tibia ash. Increased levels of this vitamin

numerically increased body weight but significantly reduced the tibia

ash. When the dietary calcium level was increased to 0.80 percent a

level of 90 I.C.U. of vitamin D3 per pound gave significantly maximum

body weight and tibia ash. Higher levels of vitamin D3 numerically in-

creased the body weight but had no influence on tibia ash. At a dietary

calcium level of 1.00 percent, the vitamin D3 response was altered. In-

creasing the level of vitamin D3 up to 180 I.C.U. per pound numerically

increased body weight but further increases in the level of this vitamin

tended to reduce growth slightly. None of the groups, however, differed

significantly in body weight or in tibia ash.

Feed utilization, expressed as grams of feed consumed per gram

of gain, was closely related to body weight. In general, an increased

body weight was associated with a decrease in the feed required to pro-

duce a unit of gain (Table 24).

The results of these studies confirm the close interrelationship

of calcium, phosphorus, and vitamin D3 in the diet of chicks. This

relationship has been observed by many authors, yet few have attempted

to establish a requirement for this vitamin in the diet of rapidly growing

chicks.






-62 -


TABLE 22

Body weight of chicks fed different levels of vitamin D3 at
different dietary calcium levels (floor pen study)


% Calcium
Vitamin D3 ..
(I.C.U./b.) 0.60 0.80 1.00 Average

Body Weight (grams)l
45 671a 11U43C 1235d 1017
90 967b 1276def 1256def 1167

180 1168c 1290def 128odef 1247

360 1246d 129ldef 1277def 1271

720 12614def 1308ef 1257de 1276
3600 1292def 1321f 1268def 1294
Average 1101 1272 1263

IMeans are average weights of 40 male and 40 female chicks.
Means bearing the same superscript do not differ significantly
(P -0.05).






-63 -


TABLE 23

Tibia ash of chicks fed different levels of vitamin D3 at
different dietary calcium levels (floor pen study)


% Calcium
Vitamin 1)3 .......
(I.C.U./lb.) 0.60 0.80 1.00 Average

% Tibia Ash1
45 42.0a 44.9bcd 45.1cde 43.9
90 43.1b 45.8de 46.4e 45.1

180 43.8bc 46.2e 146.7 45.6

360 146.2e 45.6cde 45.9de /45.9
720 44.9bcde 45.9de 46.4e 45.8
3600 14.2bcd 45.9de 46.8e 45.7
Average 44.0 45.7 46.2


bone. Means
the same


IExpressed as percent of fat-free, moisture-free
are average of 8 male and 8 female chicks. Means having
superscript do not differ significantly (P= 0.05).






- 64 -


TABLE 24

Feed utilization of chicks fed different levels of vitamin D3 at
different dietary calcium levels (floor pen study)


% Calcium
Vitamin D3
(l.C.U./Ab.) 0.60 0.80 1.00 Average

(grams feed/gram gain)l
45 2.52e 2.36d 2.25abc 2.38
90 2.37d 2.28bc 2.23abc 2.29
180 2.30cd 2.23abc 2.23abc 2.25
360 2.26bc 2.26bc 2.29bcd 2.27

720 2.26bc 2.25abc 2.22ab 2.24
3600 2.26bc 2.18a 2.25abc 2.23
Average 2.33 2.26 2.25

IMeans are average of four pens, each containing 10 male and
10 female chicks. Means having the same superscript do not differ
significantly (P -0.05).






-65 -


Under the conditions of the experiment reported herein, 90

I. C. U. of vitamin D3 per pound as suggested by the National Research

Countil is adequate to support maximum growth and bone ash at the

calcium and phosphorus levels recommended by this group (1.0 percent

Ca and 0.6 percent P). Higher levels did not significantly influence

body weight or bone ash at 4 or 8 weeks of age.

In recent years, however, the calcium requirement of the chicks

has undergone considerable study with some disagreement as to the opti-

mum level required. These reports have been recently reviewed by

Waldroup et al., (1963). With the possible advent of lowered calcium

levels in the diet, the need to re-examine the vitamin D3 requirement

becomes apparent from the results of the present studies. Lowering

the calcium level to 0.8, 0.6 or 0.5 percent significantly altered

the vitamin D3 requirement. This was true for both age groups and

regardless of whether the chicks were grown in battery brooders in

the absence of ultraviolet light or in floor pens in a conventional

broiler house. Since a primary function of vitamin D has been shown

to be the enhancement of calcium absorption from the intestial tract

(Greenberg, 1945; Wasserman et al., 1957) it is logical to assume that

the response to vitamin D supplementation would be increased as the

calcium level of the diet is lowered.

The relationship of vitamin D and phosphorus is less well defined.

The results of these studies indicated an interaction of vitamin D and

phosphorus; however, this may be a reflection of the calcium:phosphorus

interaction rather than a true effect of the vitamin on phosphorus







-66-




utilization. This hypothesis is strengthened by the early report by

Cohn and Greenberg (1939) which indicated that vitamin D did not

enhance phosphate absorption in rats reared on a vitamin D deficient,

high calcium-low phosphorus diet. The importance of adequate vitamin

D level in a biological assay for either calcium or phosphorus cannot

be over-empahsized, since marginal or deficient levels of these minerals

are often used for test purposes.














CHAPTER 8


THE AVAILABILITY OF PHOSPHORUS FRC ANIMAL PROTEIN SOURCES


There is limited information regarding the biological value for

the phosphorus in animal protein supplements when fed to chicks. Span-

dorf and Leong (l964t) reported that the biological availability of the

phosphorus in twelve menhaden fish meals averaged 99 percent and ranged

from 95 to 103 percent of the values obtained with corresponding levels

from dicalcium phosphate.

Because of the emphasis placed on linear programming/,of poultry

diets, it is important that accurate information be available regarding

the nutritional value of feedstuffs. The present experiments were design-

ed to determine the phosphorus availability of some animal protein sources

frequently used in poultry diets.


Experimental Procedure


Samples of fish meal, poultry by-products meal, and meat and

bone meal were obtained from several sources. The various samples of

the individual ingredients were blended for use in these trials. The

blended samples were analyzed for protein, calcium, and phosphorus

content by 3 laboratories. The average of these 3 analyses appears in

Table 25 and was used in formulation of the test diets. It was recognized

that protein quality of the diets could be a confounding factor; therefore,


-67 -






-68 -


TABLE 25

Analyses of animal protein sources


Composition1
Ingredient % Protein % P % Ca


Menhaden fish meal 61.4 2.94 5.27

Poultry by-product meal 58.2 2.01 4.14

Meat and bone meal 53.3 3.52 10.30


Average of analyses by three laboratories.







- 69 -


all diets were formulated to contain 25 percent protein. It was felt

that this would help to minimize any possible variation due to protein

quality of the diets.

The composition of the basal diets is presented in Table 26.

Isolated soybean protein was used to maintain a constant protein level

while corn oil and cerelose were used to maintain a constant dietary

energy level of 1000 Calories of productive energy per pound. Constant

levels of plant phosphorus (0.40O percent) were maintained by variation

in degerminated corn meal (0.10 percent P) and white corn meal (0.28

percent P).

Analytical reagent grade monosodium phosphate (NaH2P04 H20)

and feed grade dicalcium phosphate were used as standards of comparison

for phosphorus availability. The test sources were added to the basal

diets in amount sufficient to supply 0.05, 0.10 and 0.15 percent phos-

phorus, giving total phosphorus levels of 0.45, 0.50 and 0.55 percent.

These levels are below the minimum phosphorus requirement of the chick

as suggested by the National Research Council (1960). The total calcium

content of the diet was maintained at 0.80 percent by the use of reagent

grade calcium carbonate and the diet supplemented with 1000 I.C.U. per

pound of vitamin D3.

Day-old broiler chicks obtained from a commercial hatchery were

randomly assigned to pens in battery brooders. Four replicate pens,

each containing 5 male and 5 female chicks, were assigned to each dietary

treatment in 2 successive trials, resulting in a total of 80 chicks per

treatment.






- 70 -


TABLE 26

Composition of basal diets


Ingredients Percent of diet


White corn meal 34.70 36.20 33.20 30.20
Degerminated corn meal 14.oo00 12.50 15.50 18.50
Soybean meal (50% protein) 32.00 32.00 32.00 32.00
Corn oil 0.73 0.63 0.87 3.28
Cerelose 10.33 10.10 10.33 7.95
Assay protein 3.77 3.34 4.14 4.86
Iodized salt 0.40 0.40 0.40 0.40
Calcium carbonate 1.47 1.54 1.37 1.69
Micro-ingredients2 0.90 0.90 0.90 0.90
Monosodium phosphate 0.14 0.14 0.14 0.36
Dicalcium phosphate *
Fish meal 1.70
Poultry by-product meal 2.9 .
Meat and bone meal 1.29 .

% Protein 25.0 25.0 25.0 25.0
Productive energy Cal/lb. 1000 1000 1000 1000
% Calcium 0.80 0.80 0.80 0.80
% Phosphorus 0.45 0.45 0.45 0.45

1C-l assay protein, Archer-Daniels-Midland Co., Cincinnati,
Ohio.

2Micro-ingredients as given in Table 5 with 1000 I.C.U. per
pound of vitamin D.







- 71 -


Diets and tap water were consumed ad libitum from 1 to 28 days

of age at which time the experiment was terminated. Individual body

weights were obtained and 2 males and 2 females from each pen were

sacrificed for bone ash determination. Since there was no treatment X

trial interaction, results of the two trials were combined for presenta-

tion.


Results and Discussion


Body weight of chicks fed graded levels of phosphorus from

animal protein sources ranged from 95 to 99 percent of that resulting

from feeding chicks equivalent levels from the inorganic phosphorus
/
sources (Table 27). Within each level of phosphorus tested, little

variation in performance was observed between sources with the exception

of the highest level of supplemental phosphorus. It is possible that

this may be due to either the quality of the protein or an amino acid

imbalance.

Phosphorus supplied from the animal protein sources resulted

in tibia ash values that ranged from 101 to 102 percent as much as

the inorganic phosphate sources (Table 28). There was little variation

observed within each level of phosphorus supplementation.

These data support the findings of Spandorf and Leong (1964)

regarding the high availability of phosphorus in fish meal and indicate

that the phosphorus in poultry by-product meal and meat and bone meal

is highly available for chicks. Therefore, analytical phosphorus values

may be used in feed formulation without adjustment for availability.






- 72 -


TABLE 27

Body weight of chicks fed diets supplemented with phosphorus
from animal proteins and inorganic phosphate


Added Phosphorus (%)1
.... % Relative
Phosphorus Source 0.05 0.10 0.15 Av Utilization2

Body weight (grams)3
Fish meal 293ab 313bcd 334fg 313 96

Poultry by-products meal 289a 319de 326ef 311 95

Meat and bone meal 293ab 333fg 3h3g 323 99

Monosodium phosphate 300ab 323def 356h 326 100

Dicalcium phosphate 302bc 323def 355h 326 100

lIndicates percent of phosphorus from test source added to
basal diet calculated to contain 0.410 percent total phosphorus.

2Relative utilization of phosphorus from test source as caom-
pared to monosodium phosphate.
3Treatment means are average weights of 40 male and 40 female
broiler chicks. Means bearing the same superscript do not differ
significantly (P 0.05).






- 73 -


TABLE 28

Tibia ash of chicks fed diets supplemented with phosphorus
from animal proteins and inorganic phosphate


Added Phosphorus (%)l
% Relative
Phosphorus Source 0.05 0.10 0.15 Av Utilization2

Tibia Ash (%)3
Fish meal 36.7abc 38.4bcd 41.5ef 38.8 102

Poultry by-products meal 36.2ab 38.9cde 40.6def 38.6 101

Meat and bone meal 36.0a 39.7def A41.6f 39.1 102

Monosodium phosphate 35.7a 39.1cde 39.8def 38.2 100

Dicalcium phosphate 35.2a 38.2bc 41.3ef 38.3 100

lIndicates percent of phosphorus from test source added to
basal diet calculated to contain 0.40 percent total phosphorus.

2Relative availability of phosphorus from test source as com-
pared to monosodium phosphate.
3Expressed as percent fat-free, moisture-free bone. Treatment
means are averages of 16 male and 16 female broiler chicks. Means
bearing the same superscript do not differ significantly (P =0.05).













CHAPTER 9


THE AVAILABILITY OF PHOSPHORUS FROM PLANT SOURCES


The major portion of the phosphorus contained in cereals,

cereal by-products, soybeans, and other plant materials is in the

form of phytic acid inositoll hexaphosphoric acid) and its salts.

Published reports are not in complete agreement concerning the avail-

ability of this source of phosphorus. Phosphorus extracted from

various plant materials was poorly available for chicks and rats in

studies reported by Lowe et al. (1939), Krieger et al. (1940, 1941)),

Spitzer et al. (1948), Gillis et al. (1949, 1957) and Matterson et al.

(1946). However, the last group stated that one should not infer from

the poor availability of the extracted plant phosphate that phosphorus

of natural plant material is necessarily unavailable.

The reports of Heuser et al. (1943) and McGinnis et al. (1944)

suggested limited availability of phosphorus from plant sources. Gillis

et al. (1949) indicated that phosphorus present in natural plant ingredi-

ents was a slightly more effective source of phosphorus than that extracted

as calcium phytate. Singsen et al. (1947) reported that phosphorus in a

mixture of cereal grains was relatively unavailable for bone calcification

although the addition of vitamin D improved its utilization. Heat bran

phosphorus was poorly utilized by rats in the absence of vitamin D

(Boutwell et al., 1946). However, an adequate intake of this vitamin


- 74 -







- 75 -


increased the utilization of this phosphorus source for bone calcification

nearly to that of inorganic phosphorus.

The phosphorus in soybean meal was utilized by rats for both

growth and bone formation (Spitzer and Phillips, 1945 a,b). Fritz et

al. (1947) noted that under practical-conditions cereal grain phos-

phorus was well utilized by turkey poults. The phosphorus in unifine

flour was shown to be almost completely available for growth and some-

what less available for bone deposition in the chick (Sieburth et al.,

1952). Vandepopuliere et al. (1961) reported that plant source phos-

phorus was readily available for growth in chicks when fed at an optimum

Ca:P ratio of 1:1. Temperton and Cassidy (1964 a,b) concluded from

balance studies that the chick was able to absorb and retain a large pro-

portion of ingested plant phosphorus, and utilize this phosphorus for

deposition in growing bones. This supports earlier work by Singsen et

al. (1950) in which it was demonstrated by p32 tracer studies that phytin

phosphorus can move freely about the body and participate in any reaction

requiring phosphorus.

The utilization of this organically bound form of phosphorus is

of considerable practical importance since most poultry diets must be

supplemented with phosphorus for optimum performance. Therefore, it was

considered important to determine the effect of the source or form of the

organic phytin phosphorus and the influence of dietary factors upon its

availability to the chick in order to estimate the extent to which plant

phosphorus can be" used to meet the phosphorus requirement.







- 76 -


The Availability of Phytic Acid Phosphorus for Chicks


Since the report of Vandepopuliere et al. (1961) indicated that

plant source phosphorus was readily available to support growth in chicks

when fed at narrow Ca:P ratios, this trial was conducted to determine the

availability of phytic acid phosphorus and the possible effect of Ca:P
/
ratio upon its availability.


Experimental Procedure

Two trials were conducted with day-old broiler chicks. Graded

levels of phosphorus from phytic acid (0.05 to 0.40 percent) and di-

calcium phosphate (0.05 to 0.20 percent) were fed to chicks at Ca:P

ratios of 1:1 and 2:1 (Table 29). The basal diets contained 0.27 per-

cent total phosphorus.

The phytic acid was supplied in a solution containing 70 percent

phytic acid. All experimental diets were kept iso-caloric and iso-

nitrogenous by varying the amount of corn, soybean oil meal and animal

fat. Increased calcium content was obtained by increasing the level

of ground limestone.

Two replications of 5 males and 5 females were used per treat-

ment in each trial in battery brooders. Experimental diets and tap water

were given ad libitum.

Individual body weights of chicks were obtained at 4 weeks of

age. Since the diet X trial interaction was not significant, only

average weights from the combined trials are given. Three males and

3 females from each pen in trial 1 .were sacrificed for bone ash determination.







- 77 -


TABLE 29

Composition of basal diets


Ca:P Ratio

Ingredients 1:1 2:1

Percent of diet
Degerminated corn meal 64.38 63.20

Soybean meal (50% protein) 31.20 31.28

Animal fat 0.35

Ground limestone 0.32 1.07

Alfalfa meal (17% portein) 3.00 3.00

Micro-ingredientsl 0.70 0.70

Iodized salt 0.4O 0.4o0


IMicro-ingredients as outlined in Table 5.







- 78 -


Results and Discussion


Growth rate and tibia ash of chicks were significantly increased

with each increase of dietary phosphorus supplied either by phytic acid

or dicalcium phosphate (Table 30).

Growth rate and tibia ash of chicks receiving supplementary phos-

phorus from phytic acid were comparable to chicks receiving equivalent

levels of phosphorus from dicalcium phosphate. These data are in dis-

agreement with the earlier findings (Lowe et al., 1939; Heuser et al.,

1943; McGinnis et al., 194h; and Gillis et al., 1949) that phytin phos-

phorus could be utilized slightly, if at all, by the chick. However,

these data are in agreement with an earlier report by Vandepopuliere

et al. (1961) and agree with data obtained from feeding rats, where phy-

tic acid or phytin phosphorus was available for growth and bone calci-

fication (Krieger et al., 19h0; Spitzer et al., 1948).

The phosphorus source X Ca:P ratio interaction for body weight

and bone ash was found to be statistically significant (P .01). This

significant interaction was a result of slightly lowered body weights

or bone ash of chicks fed phytic acid when the Ca:P ratio was widened

as compared to an increased body weight or bone ash when the ratio was

widened with dicalcium phosphate as a phosphorus source. That widening

the Ca:P ratio interferes with utilization of phytin phosphorus agrees

with the suggestion of Vandepopuliere et al. (1961). However, it does

not explain the high availability of the phytic acid phosphorus in this

study as compared to earlier reports with the chick.






- 79 -


TABLE 30

Body weight and tibia ash of chicks fed various levels of
phosphorus franom phytic acid and dicalcium phosphate


1:1 Ca:P ratio 2:1 Ca:P ratio
Supplement
Body Tibia Body Tibia
% P added Source wt. (g) ash (%) wt. (g) ash (%)


01 279 28.8 279 27.5

.05 Phytic acid 308 31.1 297 27.0

.10 Phytic acid 3h6 32.2 344 28.1
.20 Phytic acid 362 35.1 359 35.2

.40 Phytic acid 381 37.5 .

.05 Dicalcium phosphate 270 30.6 328 27.3

.10 Dicalcium phosphate 318 31.7 366 29.5
.20 Dicalcium phosphate 35h 35.4 402 39.6

'Basal diet contained 0.27 percent phosphorus.







- 80 -


It has been shown that heat treatment increases the availability

of zinc in soybean protein (Supplee et al., 1958; and Kratzer et al.,

1959), and an interrelationship has been shown between the zinc content

of the diet and utilization of phytic acid (O'Dell et al., 1961). Since

soybean oil meals are now prepared in a different manner than those used

in the earlier work, this difference and supplementary zinc in the basal

diet may be the factors responsible for the high availability of the

phosphorus from phytic acid.


Comparison of Phytin Phosphorus Sources


Results of the previous studies indicated that the phosphorus

in a solution of phytic acid was available to the chick for growth and

bone calcification. This series of trials was conducted to determine

the phosphorus availability of salts of phytic acid.


Experimental Procedure

Three trials were conducted to determine the availability of

phosphorus as phytic acid, calcium-magnesium phytate, and sodium phy-

tate. The phytic acid* inositoll hexaphosphoric acid) contained 28.16

percent phosphorus. The supplement used was an aqueous solution con-

taining 70 percent phytic acid. The calcium phytate,** described as

phytic acid calcium-magnesium salt with an approximate analysis of 12

percent calcium, 1.5 percent magnesium and 22 percent phosphorus, was


*Nutritional Biochemicals Corp., Cleveland Ohio.

*Corn Products Co., New York, N. Y.







- 81 -


in the form of a white, odorless powder, insoluble in water. The sodium

phytate,* described as a neutral phytic acid sodium salt, contained 23.3

percent phosphorus. It was a white powder which was completely soluble

in water.

A practical type diet, using degerminated corn as the major

energy source and dehulled soybean meal as the major protein source,

served as the basal diet for all trials (Table 31). This diet was

calculated to contain 0.30 percent phosphorus, all from plant sources,

20 percent protein, and 1,000 kilocalories of productive energy per

pound.

Day-old broiler chicks were randomly assigned to pens in battery

brooders. The experimental feeds and tap water were supplied ad libitum.

Three pens, each containing 5 male and 5 female chicks, were assigned to

each of the experimental treatments in all trials.

Trial 1.-Feed grade dicalcium phosphate, calcium phytate, and

phytic acid were added to the basal diet to supply 0.10 and 0.20 percent

supplemental phosphorus, resulting in total phosphorus levels of O.hO

and 0.50 percent. A constant 2:1 ratio of calcium to phosphorus was

maintained by the addition of reagent grade calcium carbonate. Diets

were maintained iso-caloric by the addition of finely ground oat hulls.

Chicks were placed on the experimental diets at 1 day of age and main-

tained for a 28-day feeding period, at which time individual body weights

were obtained and 2 male and 2 female chicks from each pen were sacrificed

for bone ash determination.


*Nutritional Biochemicals Corp., Cleveland, Ohio.






- 82 -


TABLE 31


Composition of basal diet


Ingredient Percent

Degerminated corn 56.70

Soybean meal (50% protein) 34.00

Alfalfa meal (17% protein) 3.00

Iodized salt 0.40

Micro-ingredient s 0.90

Variable ingredients2 5.00


lMicro-ingredients as outlined in Table 5.
2Consisted of calcium carbonate, phosphorus source and oat
hulls in amounts calculated to attain desired calcium and phosphorus
levels.







- 83 -


Trial 2.-The basal diet (Table 31) was supplemented with 0.10

or 0.20 percent phosphorus from either phytic acid, calcium phytate,

sodium phytate, or monosodium phosphate (NaH2PO4 H20). This resulted

in total phosphorus levels of 0.40 and 0.50 percent. The calcium level

of all diets was maintained at 0.60 percent total calcium with 340 I.C.U.

of vitamin D3 per pound of feed. The experimental diets and tap water

were supplied ad libitum. Individual body weights were determined at

28 days of age.

Trial 3.-The basal diet (Table 31) was supplemented with 0.10,

0.20 and 0.40 percent phosphorus from phytic acid, calcium phytate,

sodium phytate, and monosodium phosphate to give total phosphorus

levels of 0.40, 0.50 and 0.70 percent. The calcium level of all diets

was maintained at 0.60 percent total calcium by the addition of calcium

carbonate.

All diets were supplemented with 360 I.C.U. of vitamin D3 per

pound. In addition, diets supplemented with 0.40 percent phosphorus

from each of the 4 phosphorus sources were supplemented with 1,080

I.C.U. of vitamin D3 per pound to determine the effects of increased

vitamin D levels on the availability of the phosphorus from the various

phytin sources.

Since the report of O'Dell et al. (1961) indicated an interaction

between calcium and phytic acid relative to the availability of zinc, it

seemed desirable to determine the effects of zinc supplementation of the

basal diet upon the availability of the phosphorus from the phytin sources.

Therefore, the diets containing 360 I.C.U. of vitamin D3 per pound and 0.40







- 84 -


percent added phosphorus from each of the 4 sources were supplemented

with 200 p.p.m. of zinc in the form of zinc sulfate and compared to

comparable diets without zinc supplementation. The experimental diets

and tap water were supplied ad libitum. At 28 days of age individual

body weights were obtained.


Results and Discussion

Trial 1.-No significant differences were observed between the

availability of phosphorus from phytic acid or dicalcium phosphorus as

determined by body weight or tibia ash (Table 32). This was true at

both levels of phosphorus supplementation. The addition of 0.10 percent

phosphorus from calcium phytate to the basal diet significantly increased

both body weight and bone ash but the response was not comparable to that

of phytic acid or dicalcium phosphate at this level of supplementation.

Increasing the level of phosphorus supplementation to 0.20 percent from

calcium phytate resulted in a slight but non-significant increase in

body weight as compared to the basal diet, but a decrease as compared

to the 0.10 level. Tibia ash was significantly increased, however, lend-

ing support to the report by Sieburth et al. (1952) that the phosphorus

from calcium phytate was relatively unavailable for growth but available

for bone deposition. In no case, however, did the degree of calcification

on the calcium phytate diets approach that attained on the phytic acid

or dicalcium phosphate diets.

Trial 2.-Diets supplemented with phosphorus from calcium phytate

did not support a level of growth equivalent to that obtained from feeding






- 85 -


TABLE 32

Body weight and tibia ash of chicks fed diets supplemented
with various sources of organic and inorganic phosphorus


Phosphorus Body weight (gms.)l Tibia ash (%)1

Source % Added M F Av M F Av

Basal diet2 0 211 200 205d 23.5 25.1 24h.3k

Calcium phytate 0.10 287 247 267c 26.3 26.6 26.5J

0.20 224 232 228d 25.5 29.2 27.91
Phytic acid 0.10 353 323 338b 30.6 32.8 31.7h

0.20 393 342 368a 39.9 39.0 39.5f
Dicalcium phosphate 0.10 365 310 338b 32.4 30.8 31.6h

0.20 388 346 367a 35.9 38.2 37.0g

lMeans bearing the same superscripts do not differ signifi-
cantly (P= 0.05).
2Basal diet calculated to contain 0.30% phosphorus. All diets
fed at a 2:1 Ca:P ratio.







- 86 -


the other phosphorus sources at either level of supplementation (Table 33).

Sodium phytate phosphorus at the 0.10 percent level of supplementation

supported a growth rate that was numerically but not significantly

superior to the calcium phytate groups. When the sodium phytate sup-

plementation was increased to 0.20 percent phosphorus, body weight data

indicated its utilization was significantly greater than that of calcium

phytate but did not approach that of the phytic acid or monosodium phos-

phate supplements. Body weight data indicated that phytic acid phosphorus

was not as available as the monosodium phosphate at the 0.10 percent level

of supplementation but was equally available at the 0.20 percent level.

Trial 3.-Comparison of the growth rate of chicks fed the phos-

phorus supplements at a level of 0.10 percent added phosphorus indicated

monosodium phosphate to be superior to the three phytin phosphorus

sources (Table 34). Phytic acid and sodium phytate were of equal value

in promoting chick growth, while calcium phytate was inferior to all

phosphorus sources tested. When the phosphorus supplementation was in-

creased to 0.20 percent, phytic acid supported a growth rate comparable

to that of chicks on diets supplemented with monosodium phosphate.

Supplementation with sodium phytate at this level did not support a

growth rate comparable to that of monosodium phosphate or phytic acid

supplementation, but was superior to calcium phytate supplementation.

Calcium phytate continued to give inferior performance; however, a sig-

nificant improvement in growth was obtained as the level of phosphorus

supplementation from this source was increased from 0.10 to 0.20 percent.







- 87 -


TABLE 33

Body weight of chicks fed diets supplemented with various
sources of organic and inorganic phosphorus



% Added phosphorus
0.10 0.20
Phosphorus source M F Av M F Av

Body weight (grams)2
Phytic acid 386 338 361fg 442 106 l4231

Sodium phytate 351 341 3145ef 04 364 383gh

Calcium phytate 349 327 337de 331 303 317d

Monosodium phosphate 435 378 I406hi i6 391 4181


iThe basal diet was calculated to contain 0.30 percent phos-
phorus, all from plant sources. All diets contained 0.60 percent
calcium.
2Means bearing the same superscript do not differ significant-
ly (P= 0.05).






- 88 -


TABLE 34

Body weight of chicks fed diets supplemented with various
sources of organic and inorganic phosphorus


Phosphorus Zinc Zinc1
Source % Added 360 D3 1,080 D3 360 D3
M F Av M F Av M F Av

Body weight (grams)2
Basal3 0 356 245 300a 410 350 380cd 316 274 295a

Monosodium 0.10 430 392 41lef ...........
phosphate
0.20 465 421 443ghi ....... ... .

0.40 478 434 456hi 483 427 458hi 489 1445 467
Phytic acid 0.O10 373 350 362bc .. *0 .

0.20 475 415 445hi ...... ......

0.40 466 428 447hi 472 417- 445hi 1 79 435 457hi

Sodium 0.10 395 345 370bc .. .. ....
phytate
0.20 398 370 384cd .. .. .. ....

0.40 461 428 444ghi 4O40 396 418efg 449 422 435fgh
Calcium 0.10 362 277 320a . .
phytate
0.20 361 335 318b ...... ......

0.40 392 367 360c 424 381 403de 371 355 363bc

1Zinc supplementation at 200 p.p.m. supplied by zinc sulfate.

2Means bearing the same superscript do not differ significantly
(P =0.05).
3The basal diet was calculated to contain 0.30 percent phosphorus.
All diets contained 0.60 percent calcium.







- 89 -


Then the level of phosphorus supplementation was increased to

0.40 percent, monosodium phosphate, phytic acid, and sodium phytate

supported an equal rate of growth. Calcium phytate supplementation at

this level significantly increased growth rate as compared to the 0.20

percent level of supplementation, but performance was inferior to the

other three sources.

Increasing the vitamin D3 level of the diet from 360 to 1,080

I.C.U. per pound at the 0.40 percent level of phosphorus supplementation

did not influence chick performance on the diets supplemented with mono-

sodium phosphate, phytic acid, or sodium phytate, but significantly in-

creased the 28-day body weight of chicks receiving supplemental phos-

phorus from calcium phytate (Table 34).

Zinc supplementation of the diets containing 0.h40 percent phos-

phorus from each of the four sources had no significant effect on 28-day

body weight (Table 34).

The results of these trials indicate that the phosphorus from

the phytic acid supplement inositoll hexaphosphoric acid) was highly

available and equal to the dicalcium or monosodium phosphates in most

instances, as measured by body weight and tibia ash. This confirms the

report of Harms et al. (1962) that phosphorus from phytic acid was as

available as that from dicalcium phosphate.

The availability of phosphorus from sodium phytate was some-

what lower than from phytic acid or the inorganic phosphates. The

availability of the sodium phytate phosphorus tended to increase as






- 90 -


the level of supplementation increased, approaching that of the di-

calcium or monosodium phosphate at high levels of supplementation.

The phosphorus in the calcium-magnesium salt or phytic acid

(calcium phytate) was essentially unavailable for growth and only

slightly available for bone calcification under the conditions of

these experiments. This confirms the reports of Matterson et al.

(1946), Sieburth et al. (1952) and Gillis et al. (1957). In contrast

to the sodium phytate supplement, the availability of the calcium phy-

tate phosphorus appeared to decline as the level of supplementation in-

creased. In only one of three experiments did higher levels of calcium

phytate continue to improve performance.

Increasing the vitamin D3 level of the diet from 360 to 1,080

I.C.U. per pound significantly increased the availability of the calcium

phytate phosphorus, but did not influence the availability of phytic

acid or sodium phytate phosphorus. This finding agrees with the reports

of several workers (Krieger and Stenbock, 1940; Boutwell et al., 1946;

Singsen et al., 1947; Spitzer et al., 1948; Gillis et al., 1957) and may

be due either to its well-known action on calcium absorption or to some

activating action on the intestinal phytase enzyme. However, Krieger

et al. (1940) reported that the calcium from calcium phytate was as

available as from calcium carbonate when adequate phosphorus was sup-

plied from inorganic phosphates, and Spitzer et al. (1948) reported that

vitamin D was not necessary for phytase formation. In both of these tests,

weanling rats were used and a species difference may be present.







- 91 -


The findings which indicate high availability for phosphorus in

phytic acid and sodium phytate appear to be a direct contradiction of the

results of Harrison and Mellanby (1939). These authors reported that

phytic acid and sodium phytate exert powerful rachitogenic actions when

added to low calcium non-rachitogenic diet while calcium phytate was

slightly antirachitic. These workers postulated that this rachitogenic

action was due to an inhibition of calcium absorption from the alimentary

canal; again, a species difference may be involved as these authors

utilized young puppies as their experimental animal.


Effect of Calcium and Vitamin D3 Levels on the

Utilization of Calcium Phytate


Results of the previous studies demonstrated that phosphorus

from phytic acid and dicalcium phosphate were of equal availability to

the chick. However, a widening of the calcium:phosphorus ratio decreased

the relative availability of the phosphorus in phytic acid to a greater

degree than phosphorus from dicalcium phosphate.

The phosphorus from the calcium salt of phytic acid was shown

to be less available than that from phytic acid or sodium phytate phos-

phorus. In view of these results, trials were conducted to further

define the influence of calcium and vitamin D3 levels on the utilization

of calcium phytate phosphorus.


Experimental Procedure

A practical type diet using degerminated corn meal as the major

energy source and dehulled soybean meal as the major protein source