Group Title: Animal science mimeograph report - University of Florida Agricultural Experiment Station ; AN65-5
Title: Effects of limiting feed intake on performance and carcass characteristics of finishing pigs
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00072958/00001
 Material Information
Title: Effects of limiting feed intake on performance and carcass characteristics of finishing pigs
Series Title: Animal science mimeograph report
Physical Description: 9 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: 1964
 Subjects
Subject: Swine -- Feeding and feeds -- Florida   ( lcsh )
Swine -- Carcasses -- Quality -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 9).
Statement of Responsibility: H.D. Wallace ... et al..
General Note: Caption title.
General Note: "August, 1964."
Funding: Animal Science Department mimeograph report ;
 Record Information
Bibliographic ID: UF00072958
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 77538260

Full Text





Animal Science Florida Agricultural
Mimeograph Report AN65-5 Experiment Station
August, 1964 Gainesville, Florida

EFFECTS OF LIMITING FEED INTAKE
ON PERFORMANCE AND CARCASS
CHARACTERISTICS OF FINISHING PIGS

H. D. Wallace, N. H. Anh, A. Z. Palmer, J. W. Carpenter and G. E. Combs /


In two previous studies (I, 2) it was observed that limiting feed intake
to 5 Ib. per head per day commencing at 100 lb. liveweight reduced rate of gain
and efficiency of feed conversion. However, all factors related to carcass
leanness were favorably influenced. Backfat thickness was reduced, loin eye
area and percent four lean cuts were increased. Carcass firmness tended to
decrease with restricted feeding.

The present study was undertaken to obtain additional information on the
above factors and to also investigate the influence of breed, starting weight
and method of feeding on results obtained by limiting feed intake.


Experimental

This study consisted of two experiments using a total of 108 crossbred
pigs. The allottment design for the two experiments is shown in Table I. Pigs
were allotted from outcome groups formed on the basis of weight, sex, and litter.
The level of feeding treatments were as follows:

LIMITED: Constant level of 5 lb. feed per head per day divided equally
between a morning and evening feeding fed in open troughs.

FULL self fed.

The composition of the feed mixtures used is shown in Table 2. All animals
were fed in dirt lots.

Experiment I was initiated April 4, 1963, and terminated July 10, 1963.
Experiment 2 was initiated October 5, 1963, and terminated January 28, 1964.

The pigs were individually weighed 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





J/ Wallace, Animal Nutritionist; Anh, Graduate Student, Palmer, Meat Scientist;
Carpenter, Assistant Meat Scientist; and Combs, Associate Animal Nutritionist,
Animal Science Department. The assistance of B. R. Cannon and L. S. Taylor,
Swine Herdsmen; Jeff Jeter, Meats Laboratory Manager and Mrs. Barbara Sullivan,
Laboratory Assistant is gratefully acknowledged.






Table I. ALLOTMENT AND TREATMENT DESIGN


Lot I 2 3 4 5
Experiment I

Number of Animals 12 12 12 12
Barrows 6 6 '6 6
GiIts 6 6 6 6

Breed Composition / 3X 3X 3X 3X
Starting Weight, Lb. 100 100 100 100
Method of Feeding Individual Individual Group Group
Level of Feeding Limited Full Limited Full


Experiment II

Number of Animals 12 12 .12 12 12
Barrows 5 5 6 6 6
Gilts 7 7 6 6 6
I/
Breed Composition 2X 3X 3X 3X 3X
Starting Weight, Lb. 100 100 120 120 150
Method of Feeding Group Group Group Group Group
Level of Feeding Limited Limited Full Limited Limited


1/ 2X indicates two-way crossbred pigs (Duroc x Landrace). 3X
(Duroc-Landrace x Hampshire).


indicates three-way crossbred pigs








-3-


Table 2. Composition of Feed Mixtures



Ingredient Expt. I Expt. II


Ground yellow corn 80.25 80.20

Soybean oilmeal (50%) 17.00 17.00

Ground limestone 1.00 1.00

Steamed bonemeal 1.00 1.00

Iodized salt 0.50 -0.50

Trace minerals / 0.05 0.05

B-Vitamin supplement 2/ 0.10 0.10

Vitamin B2 supplement/ 0.05

Antibiotic supplement/ 0.10 0.10

S100.00 100.00



I/ Adds in p.p.m.: Manganese (29.6), iron (36.5), copper (2.5), cobalt (0.83),
zinc (42.0) and potassium (3.9).

2/, Exot. I Contained 2,000, 4,000, 9,000 and 10,000 mg/lb. respectively of
riboflavin, pantothenic acid, niacin and choline chloride.

Exot. II Contained 8,000, 14,720, 36,000 and 40,000 mg./lb. respectively of
riboflavin, pantothenic acid, niacin and choline chloride.

-3/ Contained a minimum of 20 mg./lb.

4/ Exot. I Tylan 10 gm. tylosin activity per Ib.

Exot. II TM-IO 10 gm. terramycin activity per lb.






-4-


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 measure-
ment 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 lonaissimus 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

The results for experiment I are summarized in Tables 3 and 4.

Level of feeding effect As would be expected, full-fed pigs gained signi-
ficantly faster and required less time to reach final slaughter weight. The feed
required per unit of gain on an overall basis (Table 4) favored the full-fed
pigs (3.51 vs. 3.41). Differences in dressing percent, carcass length, carcass
firmness score, percent 4 lean cuts and loin eye area were not statistically sig-
nificant. The limited fed pigs were leaner as indicated by less backfat (P <.01).
Full-fed pigs yielded a higher percentage of liver (P <.01).

Method of feeding effect Significant differences were not observed for
any of the measurement criteria, except for the percent of 4 lean cuts. In this
case pigs individually fed yielded a higher percentage of 4 lean cuts (P <.05).

Sex effect It is generally accepted that gilts gain slower but more effi-
ciently and yield leaner carcasses than barrows. In this experiment gilts gained
slightly slower than barrows. Gilts were more efficient in gains and produced
leaner carcasses. The most noticeable difference was in loin eye area. A signifi-
cant interaction between sex and feed level was observed for rate of gain, thus
indicating that gilts gained relatively faster on restricted feeding, whereas
barrows gained relatively faster on the full feeding program.


A summary of experiment II is presented in Table 5.

Breed composition effect The three-way crossbred pigs generally outperformed
the two-way crossbred pigs (Lot 2 vs. Lot I). They also yielded somewhat leaner
carcasses. However, the only statistically.significant difference observed was
backfat thickness (P <.01).







Table 3. Feedlot performance and carcass data as influenced by level
feeding for the individual lots (Experiment I).


and method of


Lot Number I 2 3 4
Feed Level Limited Full Limited Full
Feeding Method Individual Individual Group Group


Number animals 12 12 12 12
Initial wt., Ib. 97.0 96.9 .97.3 ... 97.0
Final slaughter wt., Ib. 198.9 199.6 197.5 202.6
Daily gain, Ib.
First 4 weeks 1.45 1.65 1.45 .1.45
Entire period 1.42 1.65 1.41 1.68
Feed/lb. gain, entire period, lb. 3.48 3 .22 3.54 3.59
Number days on feed 72 63 72 63
Dressing percent 69.5 69.5 68.4 69.0
Carcass length, in. 30.53 30.50 30.62 30.22
Carcass firmness score-/ 1.67 2.25 2.00 2.00
Backfat thickness, i7 1.08 1.10 .05 1.21
Percent 4 lean cuts 55.42 55.41 54.17 53.71
Percent ham. 21.16 21.15 20.41 20.61
Loin eye area, sq. in. 3.87 3.89 3.83 3.74
Percent liver 3/ 1.58 1.74 1.67 1.79


I/ Hard I, medium hard 2, medium soft 3, soft 4, oily 5.

2/ Based on chilled carcass weight.

3/ Based on slaughter weight.







Table 4. Foodlot performance and carcass data as influenced by main treatment
variables (Experiment I).


Level of Feeding Method of Feedinq Sex
Comparison Limited Full Individual Group Barrows Gilts

Number animals 24 24 24 24 24 24
Initial wt., lb. 97.1 96.9 96.9 97.2 97.4 96.7
Final slaughter wt., lb. 198.2 201.I. 199.2 200.1 200.1 199.2
Daily gain, lb.
First 4 weeks 1.45 1.55 1.55 1.45 1.52 1.48
Entire period 1.41 1.67** 1.54 1.54 1.55 1.52
Feed/lb. gain, entire period, lb. 3.51 3.41 3.56 3.56 3.45 3.25
Number days on feed 72 63 68 68 68 68
Dressing percent 68.9 69.3 69.5 68.7 69.2 69.0
Carcass length, in. 30.58 30.36 30.51 30.42 30.45 30.48
Carcass firmness score 1.84 2.12 1.96 2.00 1.88 2.08
Backfat thickness, in. 1.06** 1.16 1.09 1.13 1.12 1.10
Percent 4 lean cuts 54.79 54.56 55.42* 53.94 54.21 55.40*
Percent ham 20.78 20.88 21.16 20.51 20.51 21.16
Percent loin 16.76 16.34 16.67 16.43 16.28 16.82*
Loin eye area, sq. in. 3.85 3.82 3.88 3.79 3.66 4.00*
Percent liver 1.63 1.76** 1.66 1.73 1.67 1.72


Significantly different
Significantly different


(P <.05)
(P <.01)








Table 5. Feedlot performance and carcass data
level of feeding and starting weight


as influenced by breed composition,
(Experiment II).


Lot Number I 2 3 4 5
Feed Level Limited Limited Full Limited Limited
Breed Composition 2X 3X 3X 3X 3X
Starting Weight 100 100 120 120 150


Number animals 12 12 12 12 12
Initial wt., lbs. 98.5 98.3 119.8 120.2 152.8
Final slaughter wt., lb. 198.7 201.6 201.1 199.7 199.3
Daily gain, Ibs.
First 4 weeks 1.07 1.22 1.95 1.19 -
Entire period 1.18 1.25 1..93 1.11 1.16
Feed/lb. gain, entire period. lb. 4.33 3.96 3.54 4.66 4.44
Number days on feed 88 83 42 74 41
Dressing percent 67.8i 67.7 70.2 69.1 69.2
Carcass length, in. 30.98 30.67 30.13 30.68 30.39
Carcass firmness score 2.42 2.83 2.08 2.58 2.42
Backfat thickness, in. 1.18 1.10 1.30 1.17 1.12
Percent 4 lean cuts 53.31 54.31 51.83 54.64 53.55
Percent ham 20.20 20.40 19.36 20.32 20.23
Percent loin 16.25 16.65 16.09 16.69 16.29
Loin eye area, sq. in. 3.75 3.99 4.03 4.30 3.90
Percent liver 1.55 1.52 1.74 1.45 1.46







-8-


Level of feeding effect For a direct comparison of level of feeding it is
necessary to compare Lot 3 with Lot 4. The full fed pigs (Lot 3) gained signi-
ficantly faster (P <.01) and required 16 days less time to reach slaughter
weight. Full fed pigs also converted feed more efficiently than the restricted
pigs (3.54 vs. 4.66). Full fed pigs dressed significantly better (P<.05) and
yielded a higher percentage of liver (P <.01). Restricted pigs yielded carcasses
carrying significantly less backfat and a higher percentage of 4 lean cuts
(P <.0l).

Starting weight effect For this comparison it is necessary to consider
only lots 2, 4 and 5 which were restricted commencing at respective weights of
100, 120 and 150 pounds. Differences in performance and carcass characteristics
were generally not significant. Pigs in Lot 4 (initial wt. 120 Ib.) yielded
somewhat leaner carcasses as indicated by a higher per cent of 4 lean cuts and
considerably greater loin eye area (P<.01). When compared to the full fed
group (Lot 3) restricted lots, irrespective.of initial weights, yielded
leaner-carcasses. The data suggest that 50 pounds of weight gain under a
restricted feed intake was adequate to significantly improve carcass leanness.

Sex effect In this experiment gilts gained slightly faster (1.41 vs.
1.38) and more efficiently (4.13 vs. 4.29) than barrows. Percent lean cuts and
loin;eye area were 53.82 and 4.26 respectively for the gilts and 52.86 and
3.89 respectively for the barrows.


Summary

Two experiments involving a total of 108 crossbred pigs were conducted to
study the effects of Ilimiting feed intake on performance and carcass characteristics
of finishing pigs. The relationships of breed composition, method of feeding,
starting weight and sex to feed restriction were also studied.

Feed restriction reduced rate of gain (P <.01) and efficiency of feed con-
version, increased the time to reach market weight by 9 16 days, increased
carcass length slightly, reduced backfat thickness.(P <'.01) in both experiments
and increased percent of 4 lean cuts (P <.01) in the second experiment.

There were no significant influences of breed composition on any of the
factors studied except for backfat thickness which was less in the case of the
3-way crossbred pigs.(P <.01).

Method of feeding (individual vs. group) did not significantly influence
the feed restriction effects except for per cent four lean cuts which were
greater for those pigs individually fed (P <.05) than for those fed in groups.

Pigs were restricted commencing at 100, 120 and 150 pounds live weight in
experiment II. In all cases feed restriction significantly improved carcass
leanness. The leanest, best muscled pigs were in the group which was restricted
commencing at 120 pounds live weight.








-9-


Barrows and gilts gained at about the same rate; however gilts were more
efficient and produced much leaner carcasses. Gifts appeared to tolerate the
feed restriction better than barrows as indicated by a significant interaction
(P< .05) between sex and feed level.
















References Cited

I. Wallace, H. D., A. Z. Palmer, J. W. Carpenter, N. H. Anh and G. E. Combs.
1963. The influence of feed restriction, high level copper supplementation
and sex on feedlot performance and carcass characteristics of swine. Fla.
An. Sci. Mimeo. Series No. 63-16.

2. Wallace, H. D., A. Z. Palmer, J. W. Carpenter and G. E. Combs. 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. Fla. An. Sci. Mimeo. Rpt. AN64-4.

















HDW:gem
8/10/64
1000 copies




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs