Group Title: Department of Animal Science mimeograph series - Florida Agricultural Experiment Station ; no. AN67-6
Title: An introduction to the use of electronic computers for least-cost feed formulation and cattle enterprise management
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 Material Information
Title: An introduction to the use of electronic computers for least-cost feed formulation and cattle enterprise management
Series Title: Department of Animal Science mimeograph series
Physical Description: 4 p. : ; 28 cm.
Language: English
Creator: Hentges, J. F ( James Franklin ), 1925-
University of Florida -- Dept. of Animal Science
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1966
 Subjects
Subject: Cattle -- Feed utilization efficiency -- Florida   ( lcsh )
Feeds -- Economic aspects -- Data processing -- Florida   ( lcsh )
Cattle -- Economic aspects -- Data processing -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 4).
Statement of Responsibility: James F. Hentges, Jr.
General Note: Caption title.
General Note: "November, 1966."
 Record Information
Bibliographic ID: UF00072984
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 78603993

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Department of Animal Science i,.. lorida Agricultural
Mimeograph Series AN67-6 experiment Station
November, 1966 ainesville, Florida

AN INTRODUCTION TO 'HE USE LEAT IC COMITERS 1
FOR LEAST-COST FEED FORM ATION AND CATTLE ENTERPR SE MANAGEMENT-
I.F.A.S. Univ. of Florida
Jame tes J. ..


The quest for efficiency has led to the use of electronic computers in the feed
and livestock industries. Initially, these advanced data processing units were avail-
able only to large firms who could afford to lease or purchase them. Now, computer
services are available from independent firms staffed by competent nutritionists, from
some feed manufacturers through their customer services and from some universities
through their cooperative extension programs.

The application of the mathematical procedure termed "linear programming" to feed
mixing was first reported by Waugh (1951) but its use by the feed industry developed
after publications by Heady and Candler (1958) and Hutton et al. (1953).

While the computer formulation of least-cost broiler and swine rations is a common
practice, the commercial application of these techniques to feeds for ruminant animals
has largely been restricted to the formulation of supplements, not complete balanced
rations. Publications on computer formulated least-cost rations for cattle are few
but very enlightening. Least-cost dairy ration formulation by computer methods was
reported by Howard et al. (1966) and McConnell et al. (1963). Similar reports for
beef cattle are by Church (1965), Oliver (1964), and Church et al. (1963).

The advantages of using electronic computers for livestock feed formulation are
(1) saves time in the precise balancing of modern rations, especially those with numer-
ous ingredients and those in which amino acid, vitamin and mineral element balances
are desired, (2) permits lowering of feed costs because the computer is able to check
all possible combinations of available ingredients and come up with the mixture which
will meet the nutrient requirements of the animal at the lowest possible cost, (3) pro-
vides useful information for enterprise management decisions such as the prediction of
kind of cattle to feed for most profit or rate of gain to give highest returns, best
weights and grades to buy and to sell, etc. Stated in another way, they can be used
to provide "least-cost gains" as well as "least-cost feed mixtures".

The terminology used by those who computer formulate least-cost diets may be
puzzling. The brief definitions of the following underlined terms should convey
enough knowledge for one to discuss this subject with nutrition consultants:

Nutrient Specs (specifications) give the specified quantity of each nutrient,
nutrient source, drug and other component in a feed mixture (formula) for a specific
group of cattle. The nutrient specifications must accurately reflect the nutrient
requirements of the animals being fed. NAS-NRC publications 1137 and 1349 are widely
used for some of these data. A maximum and minimum permissible range is often speci-
fied for nutrients. The content of moisture may be a fixed or variable specification


L/ Prepared by Dr. James F. Hentges, Jr., Professor and Animal Nutritionist, Institute
of Food and Agricultural Sciences, University of Florida, Gainesville, for distri-
bution at 23rd Annual Florida Nutrition Conference on November 4, 1966.







- 2-


permitting the feed mixture to be formulated on any desired dry matter basis. The
total weight specification may be for a batch mix of any .eight or for a 100 pound
mix for convenience of calculating percentages and relative nutrient values of in-
gredients.

See Table 1 for an example (not a recommendation) of the nutrient specifications
for four different diets to be offered ad libitum to growing and fattening steers in
drylot.

Ingredient Specs (specifications) give .the quantity of each ingredient permit-
ted in a given diet. Either or both maximum and minimum quantities are specified.
The judgment of the nutritionist in making these specifications often determines the
texture (appearance) of the feed mixture and its consumption (voluntary feed intake)
by cattle. Where least-cost diets are calculated frequently (some are calculated
weekly) thereby causing frequent changes in the formula, it is necessary for the per-
missible degree of ingredient change to be specified. Also, to avoid toxicity, bloat,
rumenitis, founder, and other disorders, the nutritionist must supply restrictions
and safeguards to the non-thinking computer. Mill and equipment limitations sometimes
are factors which dictate ingredient, especially molasses, specifications. See Table 2.

Estimated Nutrient Content of Ingredients is shown in tables listing the quan-
tity of each nutrient in a specified ingredient. Revised, updated tables of feed
ingredient composition are available from the National Academy of Sciences National
Research Council. These new tables employ a standardized system of nomenclature,
show all analytical data for each ingredient in one place and are part of a program
of continual recording of new data on punched cards for computer handling. One limi-
tation in cattle feed formulation by hand or by computer is an inadequacy of chemical
composition, energy utilization and voluntary intake data for ingredients, especially
forages, according to season, location, maturity, method of processing, etc. See
Table 3 for an example of the estimated nutrient content of some ingredients for fat-
tening beef cattle.

Relative Value of Ingredients (including those which may:not appear in a given
least cost formula). "Relative values" of all available ingredients are calculated
by the computer and are usually printed out for each diet for each class of cattle
or other livestock being fed. :These values are in dollars and cents so they can be
compared with actual costs per lb. in deciding on which ingredients to purchase. Also,
this affords the nutritionist who is formulating'several different diets for different
kinds of animals a better basis for deciding which ingredients to purchase because a
single ingredient might have different relative nutrient values for different classes
of animals and diets. Also, it gives the nutritionist a measure of the relative val-
ues of all ingredients in case one unexpectedly becomes available. See Table 5 for
an example of the use of "relative values" of feed ingredients.







-3 -


Examples of format for reporting computer formulated, least-cost beef cattle
diets: Table 4 shows a diet formulated during the winter of 1965-66 for the growth
and fattening of weaned calves previously conditioned to a high-concentrate :diet
containing urea.


TABLE 4



Lower Upper
Lb./Ton Ingredient Percent Cost/Cwt. Limit Limit Restrictions


177 Hominy feed 8.858 2.87 2.69 2.88
301 Wheat shorts 15.067 2.97 2.94 3.20
22 Urea, 262% C.P.E. 1.098 4.75 2.90 5.94
50 Alfalfa meal, 17% C.P. 2.500 2.84 1.43 -- 2.5 lb.
12 CDP defluorinated phosphate .599 3.89 -- 6.82
416 Dried citrus pulp 20.822 1.97 1.78 2.75
600 Bermuda grass hay 30.000 1.00 -- 1.40 < 30.0 lb.
400 Standard cane molasses-USSC 20.000 1.05 -- 1.48 < 20.0 lb.
20.0 Carey's Flo-Min 1.000 1.75 -- -- 1.0 lb.
1.1 Aurofac 10 0.056 69.50 -- -- = .056 lb.




Note in the column headed "Restrictions" that the level of alfalfa meal was
restricted to not less than 2.5%, the level of grass hay to not more than 30%, the
level of cane molasses to not more than 20%, the level of Carey's Flo-Min (trace
mineralized salt) was fixed at 1% and the level of Aurofac 10 was fixed at 0.056%.
Under the columns headed "Lower Limit" and "Upper Limit", note that more than the
minimum level of 2.5 lb. of alfalfa meal would not be included in the formula until
the cost per cwt. dropped to $1.43. Likewise, note that the cost per cwt. of hominy
($2.87) is near the upper limit ($2.88) indicating that this ingredient is near the
point where it may go out of the formula; hence, the supply of this commodity should
be depleted. On the other hand, the cost per cwt of wheat shorts ($2.97) is near the
lower limit ($2.94) or the point where a higher level may come into the formula.

Table 5 shows a different format for reporting a computer formulated, least-cost
diet for the finishing of 900 pound yearling beef steers in drylot.

In conclusion, it must be stated that a computer formulated, least-cost diet may
not give least-cost production; ultimately, the useage of electronic computers will
include, in addition to least-cost diet formulation, an analysis and prediction of
production data- rate of gain, feed consumption, efficiency of feed conversion to
weight, cost of gains, etc. See Table 6 for illustration of the latter with four
different diets. An electronic computer is a tool. It does not think. It does







-4-


not see the effect of its output on the physical well-being of the animal. It has
no control over the accuracy of the data it receives. It cannot replace the expert
nutritionist or feeder. Yet, in spite of these limitations, the advantages of elec-
tronic data processing have made the electronic computer a tool which the feed and
livestock industries must use either directly or through nutrition consultants to
stay abreast of competitors who are seeking labor and money-saving procedures for the
formulation of diets and management of livestock enterprises.



References Cited

Church, D. C. 1965. Feedstuffs 37(38):28.

Church, D. C., W. G. Brown and A. T. Ralston. 1963. J. Animal Sci. 22:898.

Heady, E. 0. and W. Candler. 1958. Linear Programming Methods. The Iowa
State University Press, Ames.

Howard, W. T., J. L. Albright, M. D. Cunningham, R. B. Harrington, and C. H.
Noller. 1966. Purdue University Research Progress Rpt. 259.

Hutton, R. F., G. A. King, and.R. V. Boucher. 1958. U.S.D.A. Prod. Res. Rpt.
No. 20.

McConnell, D. J., R. W. Stanley, and Mao Lin Liu. 1963. Hawaii Agr. Exp.
Sta. Agr. Econ. Rpt. 64.

Oliver, William W., V. 1964. Master of Science Thesis, Va. Polytechnic
Institute, Blacksburg.

Waugh, F. V. 1958. J. Farm Econ. 33:299.








JFH:jw
An.Sci.
500 copies
10-66









TABLE 1. NUTRIENT SPECIFICATIONS


Nutrient


S-F #1


Total weight
Crude protein, max.
Crude protein, min.
Digestible protein, max.
Digestible protein, min.
Added fat, max.
Added fat, min.
Crude fat, max.
Crude fiber, max.
Crude fiber, min.
Ash
Added NPN, 262% C.P., max.
Added NPN, 262% C.P., min.
TDN
ENE, megcal
ENE M, megcal
ENE P, megcalA
Calcium, max.
Calcium, min.
Phosphorus, total max.
Phosphorus, total min.
Salt, trace mineralized
Aureomycin 10'
Coarse particles, max.-
Coarse particles, min.
Moisture


100.0
100.0
0
9.0
8.2
4.0
0
8.0
13.0
7.0
0
1.5
0.5
0
63
31
32
1.0
0.5
0.5
0.4
1.0
0.056
30.0
10.0
0


S-F #2

100.0
100.0
0
9.0
8.2
4.0
0
8.0
13.0
7.0
0
1.5
0.5
0
63
31
32
1.0
0.5
0.5
0.4
1.0
0.046
30.0
10.0
0


I-F

100.0
100.0
0
8.8
8.0
4.0
0
8.0
12.0
7.0
0
1.75
0.5
0
63
27
36
1.0
0.5
0.5
0.4
1.0
0.033
25.0
10.0
0


H-F

100.0
100.0
0
8.6
7.8
4.0
0
8.0
11.0
7.0
0
2.0
0.5
0
69
29
40
1.0
0.5
0.5
0.4
1.0
0.031
20.0
10.0
0


' ENE P added to ENE M in amounts to permit daily gain of 2.25 on S F and
3.0 on others. The expected average gains are lower than these figures but
the formulae are calculated to allow efficient individuals to reach peak pro-
duction.

/ System for insuring bulk content:
Particle Factor
Hays, particles 1" 100
Corn cobs, 1/2" screen 100
Cottonseed hulls 100
Silages 100

c_ Contains 10 grams Aureomycin per lb. An average daily intake of 70 mg. per
steer is specified.










TABLE 2. INGREDIENT SPECIFICATIONS


SPECS

S-F #1 S-F #2 I-F H-F

Citrus pulp, dried, max. .30 30 30 35
Corn meal, max. 100 100 100 100
Hominy feed, max. 75 75 75 75
Corn gluten feed, max. 50 50 50 50
Corn gluten meal, max. 50 50 50 50
Wheat std. middlings or shorts, max. 35 35 35 35
Rice bran, max. 35 35 35 35
Bermudagrass hay, max. 30 30 25. 20.
Bermudagrass hay, min. 10 10 10 10
Alfalfa meal, dehyd., max. 15 15 15 15
Alfalfa meal, dehyd., min. 2.5 2.5 2.5 2.5
USSC molasses, std., max. 20 20 20 20
USSC molasses, std., min. 5 5 5 5
Defluorinated phosphate, max. 2. 2. 2. 2.







TABLE 3. ESTIMATED RELATIVE NUTRIENT CONTENT OF INGREDIENTS


Net
energy Crude Dig. Crude Cal- Phos-
megcal/lb. Prot. % Prot. Fiber cium phorus Crude
Feedstuffs NEm NEp % NPN % % % % Fat


Corn meal, yellow
Hominy feed
Corn gluten meal*-
Milo, up to 45%
of mix, SW
Corn gluten feed*
Dried citrus pulp
up to 35% of mix c/
Wheat std. middlings-
Molasses, citrus
at 5-15%*
Rice bran, solvent
Cottonseed meal,
41% solvent
Rice bran
Soybean oil meal,
44%, expeller
Urea, 262%*
Added fat, tallow
Alfalfa meal, dehy.
G. snap corn,
coarse particles
Cottonseed hulls
Peanut hulls*
Gr. corn cobs*
Grass hays
<6% protein
Alfalfa hay
>15% protein
Corn silage, well-
eared, 25% DM
Sorghum silage, all
analyses
USSC std. blackstrap
molasses at 5 to 15%
Ditto at 20%
USSC molasses #1 at
5-15%
USSC molasses premix*


95 65
101 70
95 65


71
83

83
72

80
67

75
67

95
0
170
65

85
41
5
46


49
57

57
50

53
46

52
46

65
0
117
31

59
20
3
30


8.7
10.0
42.0

9.0
26.6

6.6
16.3

4.7
14.5

41
11.5

44
262
0
17


7.8
3.6
6.8
2.5


45 22 6.0


26 15.0


28 13 2.1

23 11 2.3


-- 6.7
-- 7.1
-- 35.7

-- 5.9
-- 22.9


2.0 .02 .27 3.0
5.5 .05 .50 6.0
4.0 .15 .40 2.0

2.5 .02 .25 2.5
7.2 .48 .82 2.7


-- 4.6 11.9 2.04 0.15 3.8
-- 13.5 7.5 0.09 0.93 4.1

2.3 0 1.00 0.08 0.2
-- 9.9 12.0 0.10 1.48 2.0

- 32.5 13.0 0.15 1.10 1.5
7.8 11.6 0.08 1.36 13.5


40.5
236.0
0
12.3


4.4
0.0
1.6
--


6.0
0
0
25

10.5
43.0
60.4
32.4


- 3.0 27.6


0.27
0
0
1.58

.06
.13
.23
.11

.42


0.63 3.5
0 0
0 90.0
.26 2.0


3.0
0.9
1.1
0.5


.18 1.5


-- 10.5 28.9 1.47 0.24 2.0


-- 0.8 6.4

- 0.8 .7.8


6.5 0.0 3.9 0
6.5 0.0 3.3 0


89* 59* 15.0 3.0 11.0 0
85 58 25.0 7.2 21.0 0


.08


.06 0.8


.10 .06 0.8

1.00 .08 0
1.00 .08 0

1.4 .12 0
0.77 0.34 0


a/ Estimates mostly taken


from Lofgreen, Proc. AFMA Nutrition Council, Dec., 1963


- Asterisks indicate rough estimates based on Morrisons Feeds and Feeding, 22nd ed.
and unpublished data

/ With screenings. Wheat shorts assumed to have same relative nutrient content.


--










TABLE 6. PREDICTED FEEDLOT PERFORMANCE


Starter
Finisher #1


Wt. Range
Mean Body Wt.
Days on Feed

Daily Gain, Lb.
Gain Per Period, Lb.

Est. Consumption, Lb.
Feed Per Period, Lb.
Feed Per Lb. Gain, Lb.

Feed Cost Per Cwt of Feed

Cost Per Lb. Gain:
Feed
L & M
Total

Cost Per Period:
Feed
L & M
Total


Total Cost,
Feed
L & M
Total


All Periods:


420-525
475
70

1.7
119.0

12.5
875.0
7.4

1.81


0.134
0.05
0.184


15.95
5.95
21.90


94.19
26.67
120.86


Starter
Finisher #2

525-675
600
70'

2.0
140.0

15.2
1004.0
7.6

1.81


0.134
0.05
0.188


19.32
7.00
26.32


Intermediate
Finisher


675-808
741
70

2.5
175.0

21.5
1505.0
8.6

1.87


0.161
0.04
0.201


28.18
7.00
35.18


Heavy
Finisher

808-983
900
70

2.4
168.0

22.8
1596.0
9.5

1.95


0.183
0.04
0.223


30.74
6.72
37.46









TABLE 5. LINR PRGM 2/23/66 FINISHER NO. 5 900 LB. TO MARKET COST 2.4682

INGRED
INGRED POUNDS COST/LB. REL. VALUE ITEM SPECS NUTRIENT SEECS NUTRIENT CONTENT


BRLY-A
BRLY-B
BRLY-C
MILO-A
HMNYFD
CORN
FAT
MOLASP
BETPLP
ALFDHY
ALFOCT
OATHAY
WHEAT
DYNFRM
W iTSHT
SALT
RICBRN
PREMIX
WATER


0.
0.
47.743
0.
0.823
0.
5.000
10.000
15.000
3.000
10.000
0.
0.
5.000
0.
1.000
0.
2.000
0.434


WEIGHT 100.000


0.02500
0.02500
0.02500
0.02450
0.03250
0.02850
0.07500
0.01353
0.02410
0.02410
0.01450
0.01300
0.99999
0.01099
0.99990
0.01300
0.99990
0.05000
0.
0.


0.02625
0.02625
0.02500
0.02319
0.03250
0.02703
0.10896
0.01783
0.02238
0.01221
0.00250
0.00153
0.02830
0.01246
0.02825
-0.02718
0.01667
0.
0.
0.


BRLY-A MX
BRLY-B MX
BRLY-C MX
MILO-A MX
HMNYFD MX
CORN MX
FAT MX
FAT MN
MOLASP MX
MOLASP MN
BETPLP MX
BETPLP MN
ALFDHY MN
ALFOCT MX
ALFOCT MN
OATHAY MX
SALT EX
WHEAT MX
DYNFRM MX
DYNFRM MN


0.
0.
100.00
0.
10.00
0.
5.00
0.
10.00
5.00
15.00
15.00
3.00
20.00
10.00
0.
1.00
0.
5.00
0.


PROTEIN
PROTMN
DIGPMX
DIGPRO
FAT-MX
FAT
FIBRMX
FIBR
ASH
CALCMX
CALCIUM
P-TOTL
IOPHOS
NPNMX
NPN
TDN
ENE
EN-ME
EN-PE
D-E-S
VIT-D
VIT-A
TEXTURE
RFAGMX
RUFAGE
MSTRMX
MOISTR
BCTRCN
PREMX
PREMN
WGHTMX
WEIGHT


100.0000
0.
8.3000
7.8000
8.0000
0.
11.0000
7.0000
0.
0.6200
0.4500
0.3500
0.0300
2.0000
0.3000
0.
69.0000
0.
0.
0.0400
0.0100
0.1200
100.0000
20.0000
10.0000
17.0000
14.0000
0.2800
2.0000
2.0000
100.0000
100.000


10.9088
10.9088
7.8000
7.8000
6.4836
6.4836
8.2333
8.2333
6.3488
0.4500
0.4500
0.3500
0.1074
1.7627
1.7627
72.0986
69.0000
81.9625
55.3560
0.0400
0.0100
0.1200
-0.
13.0000
13.0000
14.0000
14.0000
0.5500
2.0000
2.0000
100.0000
100.0000




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