Group Title: Animal science mimeograph report - Florida Agricultural Experiment Station ; no. AN64-10
Title: The comparative nutritional value of dried citrus meal and corn meal for fattening cattle
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Permanent Link: http://ufdc.ufl.edu/UF00072945/00001
 Material Information
Title: The comparative nutritional value of dried citrus meal and corn meal for fattening cattle
Series Title: Animal science mimeograph report
Physical Description: 16 p. : ; 28 cm.
Language: English
Creator: Hentges, J. F ( James Franklin ), 1925-
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1964
 Subjects
Subject: Beef cattle -- Feeding and feeds -- Florida   ( lcsh )
Beef cattle -- Growth -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaves 8-9).
Statement of Responsibility: J.F. Hentges ... et al..
General Note: Caption title.
General Note: "January, 1964."
Funding: Animal Science Department mimeograph report ;
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Bibliographic ID: UF00072945
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 77522210

Full Text




o0


Animal Science orida Agricultural
Mimeograph Report AN 64-10 ,\ experiment Station
o'* Gainesville, Fla.
SJanuary, 1964.

THE COMPARATIVE NUTRITIONAL VALUE OF-
DRIED CITRUS MEAL AND.CORN.MEAL FOR FATTENING CATTLEFI/

SJ, F. Hentges, Jr., M. T. Cabezas, F. A, Capote, 2/
J. E. Moore, A. Z. Palmer,:J. W.,Carpenter and R, L. Shirley-

The outlook for an unprecedented supply of dried citrus by-products
in 1963 prompted studies to learn the extent to which dried citrus meal
might be incorporated into steer fattening diets in the future. It was
anticipated that such.diets would'be high-concentrate, probably pelleted,
mixtures with corn meal as the major energy ingredient and with the fol-
lowing ingredients-as part of the formulae: urea, defluorinated phosphate,
dehydrated alfalfa meal, an antibiotic, alkaline mineral mixture and vit-
amins A and D. .

The digestibility of nutrients in dried citrus meal and puip by
steers was reported by Mead and Guilbert (14), Neal et;al. (15, 16) and
Keener et.al. (11). The comparative feeding value oV-~round ear corn
and driee citrus pulp fed with a liberal hay allowance was reported by
Kirk et al. (12, 13), Peacock and Kirk (18), Ammerman et al. (1), Baker
(5), Tace"(17) and Jones et al. (10).

The publications by Pace (17), Baker (4, 5) and Jones (10) resulted
in recommendations being made for many years to limit the use of citrus
meal or pulp to only a part of the diet for fattening steers because lar-
ger amounts might lower gains, efficiency of feed conversion and carcass
grade. The more recent publications by Ammerman et al. (1) and Peacock
and Kirk (18) reported no significant differences-In weight gains, car-
cass grades or feed efficiency between diets containing either ground
snapped corn or dried citrus pulp as 66 to 70% of the formula.

The objectives of the experiment reported herein were to measure,the.
physiological and economic effects when dried citrus meal plus phosphorus,
and protein supplements were used to replace 0, 25, 50, 75 and 100% of the
Scorn meal in self-fed, pelleted, high-concentrate diets for yearling beef
steers.



1/ Dept. of Animal Science, Florida Agricultural Experiment Station,
Gainesville, Florida.
2/ Acknowledgment of assistance is made to Norris Cattle Co., Ocala,
SFla. for cattle, Florida Feed Mills, Jacksonville, Fla. for feed
processing, and Pasco Packing Co., Dade City, Fla, forcitrus meal.








- 2 -


Experimental Procedure

The experimental animals were yearling Hereford and Anus' steers'
which ranged in estimated slaughter grade from High Utility to Standard
at the beginning of the trial'on December 19, 1962. 'They were kept in
open sandy lots with shelter and shade provided by numerous trees., One
day before the trial, all.were drenched with 4 oz. phenothiazine fortified
with iron, copper and cobalt. An implant of 24 mg. diethylstilbestrol was
placed in the ear of each steer. Between February 4 and: March 2, 1963 one
steer died in each of the lots 1, 2 and 3. Because diagnosis revealed sus-
picion of e'nterotoxemia 'and infectious bovine' rhinotracheitis (IBR), the
remaining steers we're vaccinated with Clostridium perfringens type D toxoid
and IBR vaccine,: .

..The steers were randomly assigned to five ration treatments and were.
allowed free access to self-feeders containing the pelleted rations which
were described in table 1. Low quality grass hay. as offered ad libitum
in a different feeder. Later, the hay allowance was varied an`c controlled.
Although the steers had access to trace mineralized salt in a covered min-
eral feeder, their consumption of it was negligible, .The dried citrus meal
was derived from oranges'and was mostly dried by steam. It was classified
as a high quality product comparable in apparent nutrient value to dried
citrus pulp,' Proximate analyses on feed samples were made according to
methods of 'A.O,A.C', (2). .

The reticulorumen contents were sampled on the last day of the ex-
periment by using suction on a 1" rubber stomach tube. The samples 'were
filtered, preserved with mercuric chloride'and frozen until analyzed for
volatile fatty acid content by gas-liquid chromatography as described by
Cabezas et "al. (6).

Liveweights were recorded every :28 days. Gains in'weight were cal-
culated' on two final weight bases:: feedlot scale weight basis and empty
body weight ('EBW) basis.' For thellatter, the wet weight of the reticulo-
rumen (forestomach) and its contents were subtracted from the feedlot scale
weight. This was done to eliminate misleading, variation due to "fill" in
the forestomiach.' To calculate dressing percent, feedlot scale weights-were
shrunk, 3%;'. "

At .time of slaughter, the reticulorumen including its contents was
removed and weighed. A histological study of the rumen epithelium was
made on sections of the stomach wall which were removed from the anter-
ioventral part of the dorsal sac about 2" from the esophogeal groove.

The carcasses were evaluated independently by.University and U.S.D.A.
personnel for USDA carcass grade, carcass quality grade based on factors
other than conformation and USDA carcass yield prade. .Tenderness and
juiciness. was measured by a trained 4-member panel who tasted one-inch
thick, short loin steaks which were broiled to an internal temperature
of 1650F.








-3-


Samples of adipose tissue were taken from the layer of fat which
covered the 13th rib. The samples were rendered, filtered, sealed in a
CO2 atmosphere and frozen until analyzed. The fatty acid composition of
these samples was measured by gas-liquid chromatography and reported in
detail by Cabezas et al, (6).

The incidence and description of urinary calculii was recorded from
visual observation of bladders at the time:of slaughter.

Results and Discussion

Diet Composition A large variation among diets for content of
crude fiber, soluble carbohydrates and calcium is shown in table 2. As
the percentage of dried citrus meal (DCM) increased, the content of crude
fiber increased and soluble carbohydrates decreased. Although this shift
in carbohydrate content from relatively soluble to insoluble compounds had
little effect on the gross calorie content of the diets, it might be ex-
pected to shift microbial fermentation toward a slower production of ener-
gy yielding volatile fatty acids in the reticulorumen.

In order to eliminate the phopshorus content of the diets as a var-
iabie by equalizing the phosphorus content of all diets, 0.2% defluo-
rinated phosphate.was added with each increment of DCM. Although this
allowed a change in calcium to phosphorus ratio from 1:1 to 3:1, previous
research by Dowe et al. (8) has shown that a 3:1 ratio is not wide enough
to affect feedlot perFormance of steers. Because the phosphorus content
of these diets was twice the National Research Council recommended level,
it was of interest to note that few urinary calculi were found (table 9).

The crude protein content of the diets was within the desired range
for,all except the diet fed to lot V which was consistently 0.7% higher
than expected in each shipment of the commercially-mixed feed. No expla-
nation can be given for this extra protein; however, it is unlikely that
it affected the performance of steers since a level of 12% crude protein
in the diet was calculated to provide an adequate digestible protein in-
take.

The increase in ash content from diets I through V largely reflects
the highash content of the citrus meal because only 0.2% of defluorinated
phosphate was added with each increased increment of DCM.

Weight Gains Differences in average daily gain among lots were not
statistically significant; however, the gain of lot V was smaller than in
other lots. See table 3. The magnitude of this difference would have been
larger had it not been necessary, for economic reasons, to remove two steers
from this lot after 100 days. ,The gains of these steers dropped to 0.9
and 0.8 lb. per day during the 42 days prior to their removal. They were
the only steers in the experiment which were gaining slowly at that point.
Examination of their forestomachs revealed black, heavily-coated, apparently








-4-


parakeratotic papillae in one and flesh-colored, regressed papillae in the
other. :During the remaining 42 days of the-trial, only one more steer in
the experiment-dropped markedly in average daily gain and he was also from
lot V. His gain during the final 56 days .was. '1.28 lb. per day. Examination
of his forestomach revealed short. (.80%. ibes -than 8 immn.) flesh-colored, pap-
illae, 90% of which showed a rust-colored coating,on at least 50% of their
surface. It was estimated that 80% of the epitheliium'showed evidence of
depapillation or'regression in size of papillae:' These. observations are
interpreted as evidence that diets containing 63.2%.DCM may, at.varying
time intervals, cause susceptible individual steers to sharply decrease
their rate of gain because of: damage tbo the reticulorumen epithelium;
however, the majority of steers apparently"were n6t adversely affected.
Ammerman et al. (1) reported smaller gains, smaller daily feed intake
and necrodtc rumen epithelium when non-pelleted: fattening diets for yearl-
ing steers contained 66% dried citrus pulp. J.

Effect of Hay Restriction 'on Gains Because the- acquisition and
handling of hay or other roughages inFlorida is costly and because rou-
ghages are difficult to process and mix into diets to be fed by self-
feeders or automated feeders,. it. is of.:prime. importance to develop all--
concentrate diets which will be voluntarily consumed in desired quantities
and without digestive disorders. From days-17 to-4.4,.hay was reduced;
from an intake of 2.5 to 3,5 lb., per.rday when:offered-ad. libitum to an- ..
intake of 0.5. lb., per day,. From days 45- to.5.8., hay wa.not. fed. Signs
of distress were.seen immediately in all lots.except lot V. Figure, 1
illustrates the eating of bark from trees.by steers in lot IV which ap-
parently were craving additional roughage. "

Table. 4 shows that the average daily gain of all lots except lot V
were sharply reduced. This observation points to a need for study of the
possible substitution of citrus meal or:pulp for roughage in all-concen-
trate feed mixtures. Conversely, it illustrates the need for additional
roughage in pelleted mixtures consisting of corn meal or DCM up to 47.4%.
This observation supports Chapman et al. (7) who observed an increase in
daily feed consumption by yearling steers from 20.5 lb. without hay to
25.6 lb. with:3,0 lb. grass hay per day.- 'In another comparison, daily
feed intake was increased from 21.7 to 24.8 lb. by feeding 2.6 lb. hay
per day. Weight gains increased correspondingly. The concentrate mixture
offered to their steers was 48.8% ground snapped corn and 40.0% dried
citrus pulp which is'roughly comparable to lot IV in the experiment dis-:
cussed herein. .

During the period that hay was not fed, several steers showed mild
bloat in lots I, II and III.: Three days after hay was-removed from the
diet, one steer died suddenly in lot-I: with a disease diagnosed as-entero-
toxemia. Twelve days after hay was removed, one steer died in lot II with
enterotoxemia suspected on the basisbf- an incomplete diagnosis. It is
known that this disease, commonly called "overeating disease", is-most.pre-
valent in cattle which have consumed large quantities of low-roughage
grain diets, Whether the larger content of bulky, water-absorbent DCM
in lots III, IV and V gave protection against this disease is only









-5-.
5 -

speculation but it seems logical because of the relative insolubility of
carbohydrate content .in those diets and its probable effect:on rumen acidity.

After day 58, hay was fed at the rate of 1.5 lb. per day and all
signs of distress disappeared and gains returned to their previous .rate.

Feed Conversion to Gain.- The high efficiency of.feed utilization in
lots'I, II and III was expected because of the high-concentrate, low-fiber
nature of the diets fed to those lots. The decreased efficiency of feed
conversion in lots IV and V apparently reflects the.poorer utilization of
the concentrate portion of those diets which were largely DCM.. This re-
duction in feed conversion correlates with a.lower.content of soluble car-
bohydrates and a higher content of crude fiber. These data indicate that
about 50 to 100 lb. additional feed may be required per 100 lb; of weight
gain by yearling'steers when the diet consists of 47,4 to 63.2%.DCM.. The
daily intake of feed in lots II, III, IV and V did not-reveal a need for
a period of adjustment:to DCM in the pelleted feed mixture which was self-
fed with grass hay offered ad libitum.

Rumen Microbial Fermentation Differing rates of production of
acetic acid and propionic acid by bacterial and protozoal fermentation
of these diets are seenin table V. The addition of. DCM increased acetic
and decreased propionic acid production. The change in ratio of acetic
to propionic acid was from 1.13:1 to 4.35:1; a change large enough to ad-
versely affect the efficiency of utilization of energy from the diets con-
taining DCM. Armstrong et al. (3) has shown that the heat lost during
tissue metabolism of propionic acid is less than for acetic acid. Cabezas
et al. (6) has correlated the increase of acetic acid in rumen fluid with
a decrease in solubility of dietary carbohydrate.

Forestomach Changes The adjusted weight (RR wt./100 lb. empty body
wt.) of the reticulum and rumen compartments of the forestomach was
slightly heavier in steers from lot V. See table 6. Since papillae
density and'size were smaller in these stomachs, the increased weight
was attributed to adherent food particles on the parakeratotic papillae
and increased musculature of the reticulorumen wall.

The color of the papillae changed from a predominance of gray/ on corn
diets to dark brown on DCM diets. The change in color was due to the-
encrustation or coating of the papillae by some action or component of the
DCM diets. The encrustation also produced histological changes, mainly
parakeratinization, in the epithelium on the papillae surface.. This con-
dition has been termed "rumen parakeratosis" by-Jensen et al. (9). Whether
this condition hinders the-absorption of volatile fatty acids and other
dietary fractions is speculation but it is logical to expect hindrance
when-11 of 12 steers had more than a 60% incidence of encrusted papillae
and 10 of 12 steers had more than a 30% incidence of regressed papillae.,
as occurred in lot V. Although the average daily gain of'lot V steers had
not dropped sharply, much more individual variation was recorded than in
other lots.









-6-


The change in shape from a predominately smooth or slightly serrated
perimeter of the papillae to a predominately deeply serrated or irregular
perimeter is assumed to be a result of the increased abrasiveness of the
DCM.

Carcass Data Using current U.S.D.A. standards for grading carcasses
on the.basis of conformation.and quality, the diet containing 63.2% DCM
produced inferior carcasses because fewer were graded U.S. Choice. Also,
the dressing percent of this lot was lower than in the other lots. With
each increased increment of DCM in the diet, there was a decrease in thick-
ness of backfat over the 13th rib and marbling score of the ribeye.

Using the U.S.D.A. yield grade, which eliminates conformation as a
factor, diets containing 47.4 and 63.2% DCM were:superior.

Likewise, the estimated yield of round, loin, rump, rib and chuck was
largest and the thickness of backfat over the 13th rib was smallest for
these two lots.

There were no differences among lots for tenderness or juiciness of
steaks.

The current method of establishing carcass value on the basis of
U.S.D.A. carcass grade caused lot V to have carcasses of the lowest value;
however, the yield of edible and palatable meat may have been largest for
this lot when one considers the larger yield of primal cuts, smaller layer
of backfat to be trimmed and equal tenderness.

Depot Fat Composition Table 8 shows that a highly significant change
was recorded in fatty acid composition of backfat over the 13th rib. Rib
fat of steers fed diets containing DCM had a higher content of unsaturated
oleic acid and a lower content of saturated palmitic acid. Although the
magnitude of the difference between total saturated and unsaturated fatty
acids within lots was only 4.6% for lot I, 2.6% for lot III and 1.0% for
lot V, the fact that the fatty acid composition of depot fat in cattle can
be changed by the diet is of interest and to the credit of DCM.

Urinary Calculi A high incidence of urinary calculi had been ob-
served upon examination of bladders from steers in previous experiments
in which the diets contained large quantities of dried citrus products.
One.explanation based on opinion was that the high content of calcium in
dried citrus products upset the mineral balance causing calculi formation.
In this experiment, defluorinated phosphate added to diets containing DCM
kept the phosphorus content equal in all diets. The high calcium content
of DCM increased the calcium to phosphorus ratio from 1:1 to 3:1. No large
urinary calculi were observed; consequently, the mineral balance produced
by this method of supplementation was not calculogenic. The incidence of
calculi reported in table 9 shows traces of calculi in steers from all
lots but these were very small, hard crystals of no apparent consequence
since the steers had been on these diets for 142 days, which is the maximum
length of drylot feeding periods.








-7-


Summary

Corn meal was replaced in pelleted, high-concentrate diets for fatten-
ing steers by the addition of dried citrus meal plus sources of phosphorus
and protein. Five lots of yearling'steers were self-fed these diets which
contained the following percentages of dried citrus meal: 0, 15.8, 31.6,
47.4 and 63.2

Weight gains among lots at the end of the 142-day trial were similar
except for lot V which received the diet containing 63.2% dried citrus
meal. This level produced gains equal to.-the other lots for most steers
but was not tolerated by a few susceptible steers whose weight gains declined.

Diets containing 0, 15.8 and 31.6% .arn were converted to weight gains
with satisfactory and almost equal efficiency: :849, 855 and 843 lb. per
100 lb. gain respectively. Reduced efficiency of utilization was recorded
for diets containing 47.4 and 63.2% dried citrus meal: 901 and 958 lb.
feed per 100 lb. gain respectively. The decreased efficiency of feed con-
version correlated with an increased acetic acid and decreased propionic
acid percentage in rumen fluid. Restriction of hay.intake lowered gains on
all diets except the one containing 63.2% dried citrus meal.'

With each increased increment of dried citrus meal in the diet, there
was increased evidence of apparently harmful alteration of the rumen
mucosa: papillae which were darker, smaller and more irregular in shape;
parakeratotic papillae which were partially coated or encrusted and a high
incidence of regressed or eroded papillae.

As the percentage of dried citrus meal in the diet increased, the
dressing percentage, USDA carcass grade, marbling score and backfat thick-
ness decreased but the USDA carcass yield grade and estimated yield of rib,
loin, round and rump increased. All diets produced steaks of, excellent
and-equal tenderness and juiciness. The unsaturated fatty acid composi-
tion of backfat was increased by the addition of dried citrus meal to the
diet.










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LITERATURE CITED

1. Ammerman, C. B., P. A. van Walleghem, A. Z. Palmer, J. W. Carpenter,
J. F. Hentges, Jr. and L. R. Arrington. 1963. Comparative feeding
value of dried citrus pulp and ground corn and cob meal for fatten-
ing steers. Animal Science Mimeograph Rpt. No. AN 64-8.

2. A.O.A.C. 1955. Official methods of analysis (8th ed.). Association
of Official Agricultural Chemists. Washington, D. C.

3. Armstrong, D. G. and K. L. Blaxter. 1960. Utilization of the energy
of the end products of ruminant digestion. Proc. Fifth Int. Congress
on Nutr. p. 74.

4. Baker, F. S., Jr. 1952. Fattening cattle in North Florida. Fla.
Agr. Exp. Sta. Bul. 505.

5. Baker, F. S., Jr. :1955. Citrus molasses, dried citrus pulp, citrus
meal and blackstrap molasses in steer fattening rations. No. Fla.
Exp. Sta. Mimeograph Rpt. No. 55-3.

6. Cabezas, M. T., J. F. Hentges, Jr.,,J. E. Moore and J. A. Olson.
1964. Effect of diet on fatty acid composition of body fat in steers.
J. Animal Sci. (In press).

7. Chapman, H. .L., Jr., R. L. Shirley and T. J. Cunha. 1963. Value of
vitamins A and E for fattening steers. Everglades Sta. Mimeograph
No. 63-19.

8. Dowe, T. W., J. Matsushima and V. H. Arthaud. 1957. The effects of
adequate and excessive calcium when fed with adequate phosphorus in
growing rations for beef calves. J. Animal Sci. 16:811.

9. Jensen, Rue, J. C. Flint, R. H. Udall, A. W. Deem and C. L. Seger.
1958. Parakeratosis of the rumens of lambs fattened on pelleted
feed. Am. J. Vet. Res. 19:277.

10. Jones, J. M., R. A. Hall, E. M. Neal and J. H. Jones. 1942. Dried
citrus pulp in beef cattle fattening rations. Texas Agr. Exp. Sta.
Bul. 613.

11. Keener, H. A., N. F. Colovos and R. B. Eckberg. 1957. The nutritive
value of dried citrus pulp for dairy cattle. New Hampshire Agr. Exp.
Sta. Bul. 438.

12. Kirk, W. G., E. R. Felton, H. J. Fulford and E. M. Hodges. 1949.
Citrus products for fattening cattle. Fla. Agr. Exp. Sta. Bul. 454.

13. Kirk, W. G. and G. K. Davis. 1954. Citrus products for beef cattle.
Fla. Agr. Exp. Sta. Bul. 538.













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14. Mead, S. W. and H. R. Guilbert. 1926. The digestibility of certain
fruit by-products as determined by ruminants. I. Dried orange pulp
and raisin pulp. Calif. Agr. Exp."Sta. Bul. 409.

15. Neal, W. M., R. B. Becker and P. T. Dix Arnold. 1934. Dried grape-
fruit refuse a valuable feed. Fla. Agr. Exp. Sta. Press Bul. 466.

16. Neal, W. M., R. B. Becker and P. T. Dix Arnold. 1935. The feeding
value and nutritive properties of citrus by-products. I. The di-
gestible nutrients of dried grapefruit and orange cannery refuses
and the feeding value of the grapefruit refuse for growing heifers.
Fla. Agr. Exp. Bul. :275.

17. Pace, J. E. 1950. The feeding value of citrus by-products for growing
and fattening steers. M.S.A. Thesis, University of Florida.

18. Peacock, F. M. and W. G. Kirk. 1959. Comparative feeding value of
dried citrus pulp, corn feed meal and ground snapped corn for fatt-
ening steers in drylot. Fla. Agr. Exp. Sta. Bul. 616.












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TABLE 1. INGREDIENT COMPOSITION OF RATIONS

Lot No. I II III IV V

Varying ingredients

Corn meal 72.0 54.0 36;0 .18.0 0.0
Citrus meal 0.0 15.8 : 31.6 47.4 63.2
SBOM, 44% 2.5 3.5 4.5 5.5 6.5
CSOM, 41% 2.5 3.5 4.5 5.5 6.5
Defluorinated phosphate 0.0 0.2 0.4 0.6 0.8

Fixed ingredients

Urea, 262% 1.0 1.0 1.0 1.0 1.0
Cane molasses 5.0 5.0 5.0 5.0 5.0
Alfalfa meal 5.0 5.0 5.0 5.0 5.0
Mineral & vitamin mixa/ 2.0 2.0 2.0 2.0 2.0
Corn cobs, ground 10.0 10.0 10.0 10.0 10.0
Aurofac 10 0.0375 0.0375 0.0375 0.0375 0.0375
Grass hayb/


a/ Mineral mix contained 18.9% calcium, 5.5% phosphorus, 30% sodium chloride,
1.4% iron, 0.108% copper, 0.01% cobalt, 0.48% manganese and 0.01% iodine.
Vitamin mix contained 10,000 I.U. of vitamin D2 per lb. and was adjusted to
provide an average intake of 20,000 I.U. vitamin A per day.

b/ Varied uniformly among lots from none to two pounds per day after initially
allowing ad libitum access for 14 days.













TABLE 2. PROXIMATE NUTRIENT COMPOSITION OF RATIONS,


Lot Dry Crude Soluble Gross Ether
No. Corn Matter Nitrogen. fiber CHO/ energy extract
-- .% % %_ % Kcal/gm

I 7? 88.35 2.20 5.57 56.73- 3.81 3.86

II 54 88.43 2.24 8.79 48.67 3.86 3.55

III -36 88.53 2.32 9.38 41.51 3.78 3.51

IV 18 88.19 2.42 10.17 30.00 3.73 3.47

V 0 86.29 2.66 11.65 21.12 3.74 3.22


a/ Multiplied by 6.25 gives crude protein values of 13.7, 14.0, 14.5,
12.1, 12.4, 12.8, 13.3 and 14.6% on air-dry basis for lots 1 to 5,


Ash

9%

4.67

5.30

6.07

7.60

7.71


Cal-
cium-.



0.52

0.84

1.16

1.48

1.79


Phos-
phoruss/



0.55

0.56

0.57

0.59

0.60


Ca:P
ratioE/


1.0:1

1.5:1

2.0:1

2.5:1

3.0:1


15.1 and 16.6% on moisture-free or
respectively.


Includes starch, sugars and other carbohydrates hydrolyzed by 10% hydrochloric acid.

Estimated content.


MOISTURE-FREE BASIS


''


m












- 12 -


TABLE 3. SUMMARY OF WEIGHT GAIN AND FEED CONVERSION DATA

Lot No. I II III IV V
Corn, % 72 54 36 18 0

No. steers 14 15 15 14 12
Days in trial 142 142 142 142 142
Av. initial wt. Ib.a/ 708 717 719 710 702
Av. final wt., lb.i/ 1075 1076 1064 1064 1027
Av. daily .gain, lb.a/ 2.66 2.68 2.56 2.65 2.46
Av. empty body wt., lb.b/ 1001 998 981 986 952
Adjusted av. daily gain, Ib./ 2.04 2.14 2.00 2.14 1.99
Feed per lb. gain, lb. (air dry basis):
Concentrates 7.87 8.00 7.85 8.45 8.90
Hay 0.62 0.55 0.58 0.56 0.68
Total 8.49 8.55 8.43 9.01 9.58


a/ Initial weight shrunk 3%; final weight taken from feedlot scale, not shrunk.

b/ Initial weight shrunk 3%: final weight was empty body weight (final live
wt. less wt. of reticulorumen and its contents).













- 13 -


TABLE 4. COMPARISON OF AVERAGE DAILY WEIGHT GAINS
PERIOD OF HAY RESTRICTION ( DAY 17 TO
DURING ENTIRE 142.DAY TRIAL


Lot No.
Conn- %


(ADG) DURING
58) AND


I II III
72 54 36


ADG, day 17-58, lb.* 1.8 1.7 1.7 1.7 2.4

ADG, 142 day trial, lb. 2.6 2.7 2.6 2.6-- 2.5



i Hay was reduced from ad libitum offering to 0.5 lb. per day
from day 17 to 44 and none was fed from day 45 to 58.















- 14 -


TABLE 5. RATIO OF VOLATILE FATTY ACIDS IN RUMEN FLUID
SAMPLED BY STOMACH TUBE AT END OF TRIAL

Lot No. I III V
Corn, % 72 36 0

Acetate 44.9 56.4 69.2

Propionate 39.9 29.4 -15.9

Butyrate 11.2 10.5 12.5

Valerate 2.1 1.5 1.5

Isovalerate 2.0 2.2 0.9

Acetate:Propionate ratio 1.13:1** 1.92:1* 4.35:1*


A* P<.01.













- 15 -


TABLE 6. RETICULORUMEN (RR) DATA


Lot No..
Corn, %


RR weight, lbi/
RR wt./EBW /
Papillae color:
Dark
Gray
Flesh
Papillae length, mm.
Papillae width, mm.
Papillae shape, incidence$/
Smooth-
Serrated-
Serrated
Serratea+
Irregular
Regressed papillae, incident
30% .
31 to 59%
60%
Encrusted papillae, incident
'30%
.31-59%
60% "


I .... II Il
72 54 36

22.2 25.1 23.3
3.4 '4.0 3.7


2
8
4
15.4
5.1

.9
3
2
0'
0

: 14' -
0
0

14
0
0


d/
ce-



ce_/


3
6
6
15.6
5.3

S6
6
3
.0
0

15
0
0

'14
1-
'0


0

14
'13.8
4.0

0
3
6
5
.1

7
7
1

2
6
7


a/ Wet weight of reticulorumen at time of slaughter.

b/ Adjusted to 100 lb. empty body weight (live slaughter weight less'weight
of reticulorumen and its contents)..

c/ Describes shape of perimeter of leaf-like papilla; irregular being notched
or deeply serrated in irregular patterns.

d/ Spiralled, eroded, club-shaped and fragmented.

e/ Papillae encased in a crusty coating except for 11 stomachs in lot V where
coating resembled a crusty mud which covered lower 2/3 rather than tip of
papillae.


..IV .- V
18 0


23.1
3.9

4
7
3
13.9.
4.6

-0
0
4
8
2

5

4

14
1
0


25.2
4 2.

7
S3
2
S14.2
4.0

.O

4
1

5;'
2

2
5
5

0
1
11'











16 -


TABLE 7. SUMMARY OF CARCASS DATA

Lot No. I II I II IV V
Corn, % 72 54 36 18 0

Dressing percent/ 59.9 59.0 59.3 59.2 58.3
USDA grade:
Choice 13 11 9 11 5
Good 1 4 6 3 7

USDA yield grade/ 3.4 3.7 3.6 3.2 3.0
Estimated yield, %C/ 49.8 49.1 49.4 50.3 50.8*
Marbling scored/ 13.4 12.1 12.3 11.6 11.3
Backfat, in. 0.52 0.48 0.46 0.39** 0.35**
Internal, fat, % 2.9 3.2 2.8 2.7 2.8
Ribeye area, sq. in. 11.8 10.8 10.8 11.3 11.1

Steak tenderness:
Shear tests/ 7.52 7.40 .6.59 7.59 6.94
Panel score/ 6.65 6.67 6.64 6.13 6.53
Juiciness score-/ 5.82 5.82 5.97 5.96 5.99


* P<.05.
** P<.01.
a/ Based-on-feedlot scale weights shrunk 3% and 48-hour chilled carcass weight.
b/ Based on estimated percent yield.
C/ Estimated percent boneless, closely trimmed lean from round, rump, loin, rib
and chuck.
d/ Average small, small plus and modest minus is represented by 11,-12 and 13
respectively.
e/ Rating from 1 to 13 (less than 8 is very tender) by Warner-Bratzler instrument.
f/ Rating from 1 to 9 (6 is above average, 7 is very tender) by trained taste
panel.
g/ Rated from 1 to 9 (5 is average, 6 is very juicy) by trained taste panel.




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