Group Title: Department of Animal Science mimeograph series - Florida Agricultural Experiment Station ; no. AN67-3
Title: Effects of dietary protein levels and amino acid supplementation on the feedlot performance and carcass characteristics of growing-finishing swine
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 Material Information
Title: Effects of dietary protein levels and amino acid supplementation on the feedlot performance and carcass characteristics of growing-finishing swine
Series Title: Department of Animal Science mimeograph series
Physical Description: 6 p. : ; 28 cm.
Language: English
Creator: Wallace, H. D ( Harold Dean )
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
Subject: Swine -- Feeding and feeds -- Florida   ( lcsh )
Proteins in animal nutrition   ( lcsh )
Amino acids in animal nutrition   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references (p. 3).
Statement of Responsibility: H.D. Wallace ... et al..
General Note: Caption title.
General Note: "September, 1966."
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00072981
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 78591162

Full Text

Department of Animal Science Florida Agricultural
Mimeograph Series No. AN67-3 Experiment Station
September, 1966 Gainesville, Florida


H. D. Wallace, L. A. Britt, J. W. Carpenter,
A. Z. Palmer and G. E. Combs 17

Recent work at the Florida Station (1,2,3,4) has demonstrated the important
role of dietary protein in the production of lean pork. From these experiments it
appears that presently recommended protein levels, particularly during the finish-
ing period, are somewhat low to encourage the production of lean pork. Present-day
meat-type hogs may need a higher level of dietary protein than typical hogs of 10
years ago.

The present study was designed to compare protein levels and to study the prac-
ticality of supplementing an inadequate protein diet with the amino acids calculated
to be most limiting.


The main factors of the experimental design are shown in Table 1. The pigs
were group-fed in concrete confinement. Feed was offered ad libitum with self-feeders
and water was provided by automatic watering devices. The composition of the exper-
imental diets is shown in Table 2.

The pigs were individually slaughtered at final weights between 195 and 205
pounds. Slaughter procedures and meat analyses were similar to those outlined in
Florida Bulletin 706 (5).

Results and Discussion

Results of the experiment are summarized in Table 3.

During the first four weeks of the experiment pigs in Lot 1, which were on the
highest protein level, gained most rapidly. However, these pigs did not gain sig-
nificantly faster than the pigs in Lot 2, on the next lower protein level. Lots 1
and 2 gained significantly (P < .01) faster than Lots 3 and 4. It was clearly evi-
dent that 13 percent protein was inadequate during this early growth period. The
addition of lysine, methionine and tryptophan (Lot 4) improved rate of gain signifi-
cantly (P < .01) over the unsupplemented group (Lot 3), but did not improve perform-
ance to the level of Lots 1 and 2. Daily gains over the entire period were very
similar for Lots 1 and 2 (1.64 vs. 1.63) and both lots gained significantly faster
than Lpts 3.and 4, which registered gains of 1.36 and 1.44, respectively. The dif-
ference in rate of gain between Lots 3 and 4 was not statistically significant over
the entire period.

1/ Wallace, Animal Nutritionist; Britt, Graduate Assistant; Carpenter, Associate
Meat Scientist; Palmer, Meat Scientist; and Combs, Associate Animal Nutrition-
ist, Animal Science Department.

- 2-

The feed requirements per pound gain were quite similar for Lots 1, 2 and 4
respectively (3.37, 3.45 and 3.36). However, the low protein lot without amino acid
supplementation required 3.76 pounds of feed per pound of gain. It is evident that
amino acid supplementation improved feed utilization.

Differences between lots were not statistically significant for dressing per-
centage or carcass length. Carcasses from pigs of Lot 3 showed considerably more
backfat than those from the other three lots (P < .01). As might be expected, since
they were the fattest, carcasses from Lot 3 were also firmest. Carcasses from Lot 4
showed the least firmness.

Percent lean cuts were 52.14, 52.00, 49.20 and 52.69, respectively, for pigs
from Lots 1, 2, 3 and 4. The value of 49.20 percent for Lot 3 was significantly
less than for each of the other lots (P < .01). The values for Lots 1, 2 and 4 did
not differ significantly. It is very clear that a 13-117 protein sequence is not
adequate for maximum lean tissue development, just as it was not adequate for good
feedlot performance. The addition of amino acids produced a pronounced beneficial
effect on the lean tissue deposition, Loin eye area measurements were 3.86, 3.78,
3.24 and 3.74 square inches, respectively, for carcasses from Lots 1, 2, 3 and 4.
The same statistical differences were noted as for percent four lean cuts.

Loin eye marbling scores of 8.70, 7.96, 17.48 and 8.83 for the respective lots
indicated much greater marbling or fat infiltration for the pigs fed in Lot 3. This
value-of 17.48 was significantly greater (P < .01) than all of the.other values,
which did not differ significantly. Similarly, ether extract values for the loin
eye muscle tissue reflected the same relative differences. An inadequate dietary
protein level, or more specifically an amino acid deficiency, clearly tends to en-
courage a higher relative rate of.fat deposition.

Tenderness scores, as determined by the Warner-Bratzler'shear, showed that
chops from pigs fed in Lot 3 were significantly more tender (P < .01) than chops
from pigs fed in the other three lots. The high level of fat present in the chops
from Lot 3 would account for this difference. However, the real value of this great-
er tenderness is certainly open to question, inasmuch as the chops from the leaner
hogs (Lots 1, 2 and 4) were quite satisfactory in tenderness. Taste panel scores
also indicated a difference in tenderness favoring Lot-3 pigs, but in general did
not reveal the marked differences shown by the shear apparatus.

A sex comparison is presented in Table 4. The expected differences between
gilts and barrows were observed. Barrows gained significantly faster, while gilts
generally excelled in all carcass characteristics.


Eighty-eight pigs were fed in an experiment to study the relationship of dietary
protein to feedlot performance and carcass characteristics. The following treatments
were involved: 19-17 percent protein, 17-15 percent protein, 13-11 percent protein
and 13-11 percent protein supplemented with lysine, methionine and tryptophan.

A comparison of the performance of pigs fed the two higher protein levels indi-
cated that the 17-15 percent sequence was adequate in all respects and no improvement
was obtained at the higher 19-17 percent sequence.


Pigs fed the 13-11 percent protein diet gained significantly slower, were much
less efficient in feed conversion and yielded carcasses that were fatter.with con-
siderably less lean cut yield.

When the 13-11 percent protein diet was supplemented with the amino acids, feed-
lot response was improved, but most noticeable was the marked improvement in carcass

Barrows gained faster, while gilts yielded superior carcasses.

Literature Cited

1. Wallace, H. D., M. E. Palmer, A. Z. Palmer, J.,W. Carpenter and G. E. Combs.
1963. The influence of protein level on feediot performance and carcass char-
acteristics of barrows and gilts. Animal Sci. Mimeo. Series AN64-7.

2. Wallace, H. D., A. Z. Palmer, J. W. Carpenter, Ghazi Taki and G. E. Combs.
1964. The influence of protein level on feedlot performance and carcass char-
acteristics of barrows and gilts. Animal Sci. Mimeo. Series AN64-16.

3. Crum, R. C., Jr., H. D. Wallace, A. Z. Palmer, J. W. Carpenter and G. E. Combs.
1964. The influence of protein level on feedlot performance and carcass char-
acteristics of barrowsi;and gilts. ,Animal Sci. Mimeo. Series AN65-3.

4. Wallace, H. D., A. Z. Palmer, J,*W. Carpenter and G. E. Combs. 1965. A study
of the relationship of feed restriction and dietary protein level'in finishing
hogs. Animal Sci. Mimeo. Series AN65-9..' ..

5. Wallace, H. D., A. Z. Palmer, Ji. W. Carpenter and G. E. Combs. 1966. Feed re-
striction of swine during the finishing period. Fla. Agr. Exp. Sta. Bul. 706.

6. A.O.A.C. 1960. Official Methods of Analysis (9th Ed.). Association of Offi-
cial Agricultural Chemists, Washington, D.C.

1200 copies


Table 1. Experimental design

1 2 3 4

Number of pigs 22 22 22 22
Number of males 11 11 11 11
Number of females 11 11 11 11
Dietary protein level fed to 100 lb.
liveweight (%) 19 17 13 13
Dietary protein level fed from 100 lb.
to slaughter (%) 17 15 11 11
Amino acid supplementation -/
L-lysine (%) ---- ---- ----- 0.27
DL-methionine (%) ----- ----- ----- 0.07
DL-tryptophan (%) ----- ----- ----- 0.03

1/ The amino acids were added at levels calculated to provide the same total of
these amino acids as provided by the 17% protein diet.

Table 2. Composition of experimental diets ; -

'. dCrude.protein level (.)
Diet components 19 17 15 13 11

Yellow corn 72.45 77.35 81.75 86.65 91.55
Soybean oilmeal (507) 24.90 20.00 15.50 10.50 5.50
Steamed bonemeal 1.50 1.50 1.60 1.70 1.80
Ground limestone 0.50 0.50 0.50 0.50 0.50
Iodized salt 0.50 0.50 0.50 0.50 0.50
Trace mineral premix 1/ 0.05 0.05 0.05 0.05 0.05
Vitamin premix 0.10 0.10 0.10 0.10 0.10
Vitamin B12 supplement 3/ 0.05 0.05 0.05 0.05 0.05

1/ Contained 11% calcium, 10% manganese, 10% iron, 10% zinc, 17 copper, 0.3%
iodine and 0.1% cobalt.

2/ Contained 8,000, 14,720, 36,000 and 40,000 mg. per lb., respectively, of ribo-
flavin, pantothenic acid, niacin and choline chloride.

3/ Contained a minimum of 20 mg. B12 per pound.

- 5 -

Table 3. Influence of dietary protein level and amino acid supplementation
on the feedlot performance and carcass characteristics of growing-
finishing swine.

Lot number 1 2 3 4
Protein level (%) 19-17 17-15 13-11 13-11
Amino acid supplementation / +

Number of pigs 22 22 22 22
Average initial weight, lb. 45.5 45.5 45.4 45.4
Average slaughter weight, lb. 199.5 200.4 200.0 200.3
Average daily gain, lb.
First 4 weeks 1.49 1.42 0.99 1.18
Entire period 1.64 1.63 1.36 1.44
Feed required per lb. gain :lb. 3.37 3.45 3.76 3.36
Dressing percent 2/ 71.08 70.90 71.15 71.09
Carcass length, in. 2/ 30.28 30.72 30.44 30.57
Backfat thickness in. / 1.28 1.29 1.41 1.26
Carcass firmness 2.13 2.18 1.72 2.59
Percent 4 lean cuts 2/ 52.14 52.00 49.20 52.69
Loin eye area, sq. in. 2/ 3.86 3.78 3.24 3.74
Loin eye marbling3 core 8.70 7.96 17.48 8.83
Firmness of lean -4 3.50 3.68 2.54 3.37
Percent protein in loin eye muscle 22.36 22.43 20.15 22.27
Percent ether extract in loin eye
muscle l/ 4.05 4.89 8.10 4.21
Percent moisture in loin eye muscle 73.59 73.11 71.77 73.58
Warner-Bratzler shear score 2/5 6.84 6.72 5.55 6.65
Tenderness taste panel score 2/5/ 5.54 5.77 5.93 5.74

1/ See Table 1.

2/ See Florida Bulletin 706.(Reference No. 5).

3/ Scale of 1 5 with 1 designating firm; 2, medium firm; 3, medium
5, oily.

soft; 4, soft;

4/ Closely trimmed eye muscle taken at tenth rib. Triplicate samples analyzed by
Association of Official Agricultural Chemists (1960) procedures (Reference No. 6)

5/ On one-inch thick loin chops taken at the 8th and 9th ribs, fried for 5 minutes
in a deep fryer pre-heated to 3500 F; two 1/2 inch cores taken from 8th rib for
Warner-Bratzler shear; both chops tested by taste panel.

- 6-

Table 4. Influence of sex on feedlot

performance and carcass character-

Gilts Barrows

Number of pigs 44 44
Daily gain, 1st 4 weeks, lb. 1.24 1.31
Daily gain, entire period, lb. 1.43 1.60**
Dressing percent 72.00**- 70.41
Carcass length, in. 30.66** 30.35
Backfat thickness, in. 1.28 1.35**
Carcass firmness 2.13 2.18
Percent four lean cuts 52.11* 50.91
Loin-eye area, 3.75* 3.54
Loin-eye marbling 9.70 11.79*
Firmness of lean 3.27 3.27
Percent protein in loin eye muscle 22.04* 21.56
Percent ether extract in loin eye muscle 5.06 5.55
Percent moisture in loin eye muscle 72.94 72.92
Warner-Bratzler shear score 6.59 6.29
Taste panel score .. 5.69 5.81

* Significantly greater (P < .05)w'.
** Significantly greater (P < .01).

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