Group Title: Animal science mimeograph report - Florida Agricultural Experiment Station ; AN64-5
Title: The influence of feeding a constant level of feed from 100 pounds liveweight to market weight on feedlot performance and carcass characteristics of swine
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 Material Information
Title: The influence of feeding a constant level of feed from 100 pounds liveweight to market weight on feedlot performance and carcass characteristics of swine
Series Title: Animal science mimeograph report
Physical Description: 6 p. : ; 28 cm.
Language: English
Creator: Wallace, H. D ( Harold Dean )
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1963
 Subjects
Subject: Swine -- Feeding and feeds -- Florida   ( lcsh )
Swine -- Growth -- Florida   ( lcsh )
Swine -- Carcasses -- Quality -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: H.D. Wallace ... et al..
General Note: Caption title.
General Note: "July, 1963."
Funding: Animal Science Department mimeograph report ;
 Record Information
Bibliographic ID: UF00072940
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 77520231

Full Text






Animal Science Florida Agricultural
Mimeograph Report AN64-5 Experiment Station
Gainesville, Florida
July, 1963


THE INFLUENCE OF FEEDING A CONSTANT LEVEL OF
FEED FROM 100 POUNDS LIVEWEIGHT TO MARKET WEIGHT ON
FEEDLOT PERFORMANCE AND CARCASS CHARACTERISTICS OF SWINE

H. D. Wallace, A. 2. Palmer,
J. W. Carpenter and G. E. Combs


In an earlier report ( An. Sci. Mlmeo series No. 63-16) pigs
allowed a constant level of 5 Ib. feed per head per day starting at
100 lb. liveweight gained slower than self fed pigs and required 17
days longer to reach a market weight of 200 Ib. Feed conversion was
not improved by the restricted feeding. Percent of four lean cuts was
significantly increased and dressing percent and carcass firmness were
significantly decreased by limited feeding.

The present study was undertaken to further investigate the con-
stant level of feed intake method as a means of improving the effi-
ciency of producing good quality lean pork.
Experimental

This study consisted of two experiments, each of which involved
forty-eight crossbred pigs. In each experiment the pigs were allotted,
at an approximate weight of 100 lb. from outcome groups formed on the
basis of weight, sex and litter, to two lots of 24 pigs each. In
experiment I there were fifteen gilts and nine barrows on each treat-
ment. In experiment 2 there were 9 gilts and 15 barrows on each treat-
ment. The feeding treatments were as follows for both experiments:

Lot I constant level of 5 lb. feed per head daily divided
equally between a morning and evening feeding. In experiment I the
feed was wetted at each feeding while in experiment 2 the feed was
offered dry.

Lot 2 self fed.



I/ Wallace, Animal Nutritionist; Palmer, Associate Meat Scientist;
Carpenter, Assistant Meat Scientist; and Combs, Associate Animal
Nutritionist, Animal Science Department. The assistance of
W. E. Collins and L. S. Taylor, Swine Herdsmen; Jeff Jeter,
Meats Laboratory Manager and Richard Newman and Mrs. Barbara
Sullivan, Laboratory Assistants is gratefully acknowledged.










The composition of the feed mixture fed all pigs in both experi-
ments Is shown in Table 1.

Table I, COMPOSITION OF
FEED MIXTURE FED ALL PIGS IN BOTH EXPERIMENTS

Ground yellow corn 80.25
Soybean meal (50%) 17.00
Ground limestone 1.00
Steamed bonemeal 1.00
Iodized salt 0.50
Trace minerals 1/ 0.05
Vitamin supplement 2/ 0.10
Tylan (tylosin supplement) 3/ 0.10

100.00
I/ Adds in p.p.m.: Manganese (29.6), Iron (36.5), copper (2.5),
cobalt (.83), zinc (42.0) and potassium (3.9).

2/ Adds per pound of ration: vitamin B12 (4.5 mcg.), Niacin
(9.0 mg.), riboflavin (2.0 mg.), pantothenic acid (4.0 mg.) and
choline chloride (98 mg.).

3/ Eli Lilly and Co., contains 10 gm. tylosin per lb.

Experiment I was initiated on September 5, 1962 and Experiment 2 was
initiated on December 22, 1962. Both experiments were conducted in lots
with limited forage available. In experiment I the lots were about acre
in size while in experiment 2 the lot size was I acre.

The-pigs iere individually woighed off test for slaughter at 200+ 5
pounds. The pigs were weighed on and off test in a "full" state of fill.
In order to minimize the variation in fill between full-fed and restricted
pigs all animals were weighed off at approximately 9 A.M. or about I hour
after the restricted pigs had consumed their morning feed.

The pigs were slaughtered and dressed packer style for carcass study.
Carcass weights and measurements were taken after the carcasses had been
chilled for 48 hours at 34 36 degrees F. Length of carcass was obtained
by a measurement from the anterior edge of the aitch bone (pelvis) to the
anterior edge of the first rib. Backfat thickness was calculated as an
average of measurements taken at the first rib, last rib and last lumbar
vertebra. A tracing was made of the perimeter of the longisslmus dorsi
muscle (loin eye), exposed by cutting the loin perpendicular to the
vertebral column equidistant between the tenth and eleventh ribs. The
area of the loin eye muscle was then determined by use of a compensating
polar planimeter. The carcasses were broken down by a standard procedure
(Reciprocal Meat Conference, 1951).











Results and Discussion

A summary of the data obtained on feedlot performance and carcass
effects Is presented in Table 2. A presentation of data compiled which
compare the performance of gilts and barrows under the two feeding regimes
is presented in Table 3.

Experiment Ir Full-fed pigs gained much faster as would be expected.
Pigs in this group required approximately 20 days less time to reach 200
lb. liveweight. Feed conversion also favored the full-fed pigs.

Dressing percent was significantly higher for the restricted pigs.
Carcass length was slightly greater, backfat thickness significantly less,
carcass firmness significantly less, loin eye area greater, percent 4 lean
cuts greater and percent liver significantly less for the restricted or
constant level pigs.

Experiment 2 The overall performance of the pigs in this experiment
was not as good as In experiment 1. Full-fed pigs again gained much
faster and required approximately 23 days less to reach 200 lb. livewe!ght.
Feed conversion was very much in favor of the full-fed pigs.

In this experiment full-fed pigs dressed significantly higher than
restricted pigs. This is in contrast to results of experiment I, but in
agreement with previous work. No reason is readily apparent for the
discrepancy. Carcass length was slightly greater, backfat thickness
significantly less, carcass firmness significantly less, loin eye area
greater, percent 4 lean cuts significantly greater and percent liver sig-
nificantly less for the restricted pigs.

Work at the Illinois station has consistently demonstrated about a 10 -
15 percent saving In feed with a feed restriction method similar to that
employed In this experiment. In the Illinois work the pigs were individ-
ually fed, the feed had been wetted, and the animals were shrunk prior to
tabulating final weights. Any one or all of these factors plus the
difference in the type of hogs used may have contributed to results rela-
to feed conversion. It did appear that In the present study the 5 Ibs. of
feed was too severe a restriction for the animals, particularly during the
final days of the experiment.

The data comparing gilts and barrows (Table 3) show the usual sex
differences. Carcass lengths were slightly greater for gilts, backfat was
greater for barrows, and loin eye area and percent 4 lean cuts were
markedly in favor of the gilts. Feed restriction appeared to effect gains
and carcass measurements in a similar manner for gilts and barrows. Car-
casses from barrows were firmer, probably reflecting the greater degree of
finish.











Table 2. THE INFLUENCE OF FEED RESTRICTION ON
FEEDLOT PERFORMANCE AND CARCASS CHARACTERISTICS OF SWINE
- --II


EXPERIMENT I
CONSTANT-LEVEL


Number of animals
Initial wt., lb.
Final slaughter wt. lb.
Daily gain, lb.
Daily feed intake, lb.
Feed per lb. gain, lb.
Number days on feed
Dressing percent
Carcass length, in.
Backfat thickness, in.
Carcass firpeoss score I/


Loin eye area, sq. in.
Percent 4 lean cuts 2/
Percent liver 2/


- 7
198.8
1.46
5.00
3.46
68.6
70.0
30.1 I
1.04
2.38
4.05
54.44
2.57


EXPERIMENT 2


FULL-FED

24
99.6
205.9
2.03**
6.73
3.34
52.7
68.5**
30.0
I. 18**
1.92*
3.71
52.94
3.10**


CONSTANT-LEVEL


24
101.7
194.0
1.27
5.00
4.04
74.6
68.8
29.6
1.05
2.58
3.93
55.17
2.35


FULL-FED

24
101.2
196.9
1.84**
6.41
3.55
53.0
69.6*
29.4
1.25**
1.88**
3.87
53.18**
2.57**


I! Hard I, medium hard 2, medium soft 3, soft 4, oily 5

2/ Based on chilled carcass weight

* Significantly different (P<.05)


** Significantly different (P <.O)


-2.35


~~----











Table 3. THE RELATIONSHIP OF SEX TO THE INFLUENCE OF
FEED RESTRICTION ON FEEDLOT PERFORMANCE AND CARCASS CHARACTERISTICS OF SWINE


CONSTANT-LEVEL
GILTS


Number of animals
Initial wt., lb.
Final wt., Ib.
Daily gain, lb.
Dressing percent
Carcass length, in.
Backfat thickness, in.
Carcass firmness score I/
Loin eye area, sq. in.
Percent 4 lean cuts 2/
PpreAnt liver 2/


24
98.6
196.9
1.35
69.7
29.9
1.00
2.71
4.31
55.54
2.48


BARROWS

24
102.8
195.9
1.38
69.0
29.8
1.10
2.25
3.66
54.07
2.46


FULL-FED
GILTS

24
98.9
202.0
1.93
68.9
29.9
1.14
2.13
3.95
54.10
2.85


I/ Hard I, medium hard 2, medium soft 3, soft


- 4, oily 5


2/ Based on chilled carcass weight


BARROWS

24
101.8
200.8
1.95
69.3
29.5
1.30
1.67
3.68
52.03
2.81


--


-~--









Summary

Two experiments, involving a total of 96 pigs, were conducted to
study the effect of constant-level feeding (5 Ib. per heed per day) from
initial weight of 100 lb. to a slaughter weight of 200 lb. on feedlot
performance and carcass characteristics.

The constant-level feeding procedure Increased the time required
to reach 200 lb. by approximately three weeks, reduced efficiency of
feed conversion, Increased length of carcasses slightly, reduced back-
fat thickness significantly, increased loin eye area, and Increased percent
4 lean cuts considerably (highly significant In Experiment 2). Full-fed
pigs yielded significantly firmer carcasses.

The data Would not support favorable recommendations for the constant-
level feeding regime as applied under the conditions of this experiment.

However, additional work is needed to determine the possibility of
using higher levels of feed and/or initiating the restriction at heavier
weights. The very lean type pigs used In this study did not seem to be
well suited to severe feed restriction.



























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7/17/63
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