Animal Husbandry and Nutrition Florida Agricultural
Mimeograph Series No. 60-11 Experiment Station
February, 1960 Gainesville, Florida
PASTURE vs. CONCRETE FOR GROWING-FINISHING
SW1NE WITH SPECIAL EMPHASIS ON THE CARCASSES PRODUCED
H. D. Wallace, G. E. McCabe, A. Z. Palmer, M. Koger,
J. W. Carpenter and G. E. Combs I/
In previous reports by Wallace and Combs (Fla. An. Husb. and Nutr.
Mimeo. Series No. 59-3, 1958.) and Christmas et al. (Fla. An. Husb. and
Nutr. Mimeo. Series No. 59-6, 1959.) pigs fed in concrete confinement
gained at approximately the same rate as pigs fed on good legume or millet
pastures. The feed.replacement values of the pastures were small and were
considerably less than the cost involved in growing the forage. In the
latter study carcass data indicated that pasture-fed pigs were somewhat
leaner than the pigs fed on concrete. The present experiment was under-
taken to further investigate the effects of the two systems of feeding on
feedlot performance with special emphasis on the meatiness of carcasses
Eighty weanling pigs of mixed breeding were divided into eight lots
of ten pigs each according to weight, breed, sex and litter. Four lots
were self-fed on concrete and four lots on a mixture of wheat and oats
pasture. The pigs were slaughtered individually as they reached designated
weights shown in Table I.
Table I. EXPERIMENTAL TREATMENTS
Lot No. Initial Av. Initial Slaughter Feeding Meho
No. pigs weight, lb. weight, Ib.L/ Feeding
1 10 42.9 150 In concrete confinement
2 10 41.1 180 in concrete confinerrw-i
3 10 42.8 210 In concrete confinement
4 10 42.7 240 In concrete confinement
5 10 43.1 150 On pasture
6 10 43.2 180 On pasture
7 10 42.9 210 On pasture
8 10 41.6 240 On pasture
1/ Individual slaughter weight f 3 lb.
1/ All pigs were self-fed. -
./ Wallace, McCabe, Palmer, Koger, Carpenter and Combs; Asso 'Animal'.
Husbandman, Graduate Assistant, Associate Animal Husband ,Animal Hus
bandman, Assi.stant Animal Husbandman and Assistant Ani na u I ndran,
respectively, Department of Animal Husbandry and Nutriti The ssi
tance of W. E. Collins and L. S. Taylor, Swine Herdsmen s ratefulft'VO,
The compositions of experimental rations are presented in Table 2.
Table 2. COMPOSITIONS OF EXPERIMENTAL RATIONS I/
Constituents 14% protein 12% protein
Ground yellow corn 77.0 84.3
Soybean oilmeal (44%) 20.3 13.0
Ground limestone 1.0 1.0
Steamed bonemeal 1.0 1.0
Iodized salt 0.5 0.5
Trace minerals 0.1 0.1
Lederle Fortafeed 2-49C / 0.1 0.1
A urofac 10-A ./ 0.1 0.1
The 14 percent ration was fed until the pigs averaged 125 pounds. At
this time the protein level was reduced to 12 percent.
2/ Contains 2,000 mg. riboflavin, 4000 mg. pantothenic acid, 9,000 mg.
niacin, 10,000 mg. choline chloride and 60 mg. folic acid per pound.
./ Contains 10 gm. chlortetracycline per pound.
All hogs were dressed packer style. Carcass weights and measurements
were taken after chilling 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
longissimus dorsi muscle (loin eye), exposed by cutting the loin perpen-
dicular to the vertebral column at the tenth rib. The area of the loin eye
muscle was then determined by use of a compensating polar planimeter. Per-
centage lean cuts was determined on a carcass basis by combining the weights
of the trimmed hams, loins, picnics and Boston butts and relating this
weight to the chilled carcass. Percentage lean cuts was also determined on
the basis of live weight by relating the weight of these cuts to the live
weight of the animals.
The experiment was initiated in December, 1958 and terminated in June,
Results and Discussion
A summary of the experimental results is presented in Table 3.
There were marked differences in all criteria studied due to weight
at slaughter. However, the details of this aspect of the study will be
considered in a subsequent report and will not be discussed in this paper.
Pigs fed in concrete confinement gained 1..41 pounds per day while those
fed on oats-wheat pasture gained 1.50 pounds. The difference was highly
significant. This difference in gain was similar to previous observations
in which pigs fed on pasture during the winter months in Florida have usually
outgained similar pigs fed in-concrete-confinement. On the other hand pigs
Table 3. COMPARATIVE FEEDLOT PERFORMANCE AND CARCASS
CONCRETE CONFINEMENT AND ON PASTURE
DATA FOR P!CS FED IN
Lot No. Daily Feed per Dressing Carcass Av. Backfat Loin eye Percent Percent
No. Pigsl/ Gain Ib. gain Percent Length thickness area Lean cuts Lean cuts
(Ib.) (b.) (in.) (in.) (sq. in.) carcass live wt.
wt. basis basis
1 0 1.34 3.24 71.2 26.7 1.11 3.19 53.4 38.0
2 9 1.39 3.20 70.9 28.4 1.21 3.75 53.9 38.2
3 10 1.48 3.35 71.7 29.1 1.42 3.89 50.2 36.0
4 10 1.43 3.52 72.1 30.7 1.46 4.20. 50.3 36.2
Concrete pigs, 1.41 3.33 71.5 28.7 1.30 3.76 51.9. 37.1
5 9 1.42 3.28 71.7 26.8 1.03 3.41 54.3 38.9
6 9 1.50 3.32 71.0 28.5 1.22 3.59 .. 53.0 37.6
7 10 1.54 3.36 71.2 29.1 1.48 3.91 51.3 36.5
8 9 1.53 3.40 72.8 30.7 1.47 4.55 49.6 36.1
Pasture pigs, I.50** 3.34 71.7 28.8 1.30 3.87 52.0 37.3
One pig was
removed from each of
lots 2, 5, 6 and 8 early in the experiment due to anal prolapse.
SSignificantly faster than concrete pigs (P L .01).
in confinement invariably outgain pigs fed on pasture during the summer and
early fall months.
Feed required per pound gain was almost identical (3.33 vs. 3.34) for
the concrete and pasture pigs. This indicates that the forage did not re-
place any feed under the conditions of this experiment. Thus, when well
fortified rations are fed it is difficult to justify the use of costly
forage in the growing-finishing ration.
Carcass evaluation criteria indicated only slight and non-significant
differences in the carcasses produced on concrete as compared to those
produced on pasture. Both groups of pigs dressed well (71.5 vs. 71.7).
Average carcass'lengths were very similar (28.7 vs. 28.8). Backfat thick-
nesses averaged exactly the same at 1.30 inches. Loin eye area measurements
favored slightly the pasture pigs (3.76 sq. in. vs. 3.87 sq. in.). Per-
centage lean cuts were almost identical (51.9 vs. 52.0 on the carcass basis
and 37.1 vs. 37.3 on the live weight basis). These results suggest that
pigs reared in concrete confinement produce carcasses comparable to those
produced from pigs fed on pasture.
Eighty pigs were used to study feedlot performance and carcass value
as influenced by feeding growing-finishing pigs in concrete confinement as
compared to feeding on oats-wheat pasture during the winter and early spring
months of 1958 and 1959.
Pigs fed on pasture during this winter trial gained significantly faster
(P L .01) than pigs fed in confinement.
Total feed requirements were similar for pasture-fed and confinement-
reared pigs, indicating that the forage did not replace any feed under the
conditions of this experiment.
The method of feeding appeared to have very little influence on the
leanness and quality of carcasses produced.