Department of Animal Science Florida Agricultural
Mimeograph Series No. AN66-9 Experiment Station
January, 1966 Gainesville, Florida
THE INFLUENCE OF DIETARY SAND ON THE
FEEDLOT PERFORMANCE AND CARCASS CHARACTERISTICS
OF GROWING-FINISHING SWINE
H. D. Wallace, A. Z. Palmer, J. W. Ca center, G. E. Combs
and R. H. Houser-
This investigation was undertaken to determine whether sand might be used to
advantage in the diet of the growing-finishing pig. Of particular interest was
the possibility that sand might serve as a useful diluent, and thus provide a means
of restricting nutrient intake. Various high-fiber feed materials have been used
in this manner to improve carcass leanness. However, these materials have gener-
ally increased feed costs, probably because of the added cost of grinding the dil-
uent material and a greater tendency toward feed wastage. Sand would have the ad-
vantage of being a very cheap material that would not have to be ground.
Ninety-two crossbred pigs (Duroc-Landrace x Hampshire) were divided into out-
come groups according to weight, litter and sex, and allotted to four pens of twenty-
three pigs each. The feeding treatments were as follows:
Lot 1 Basal
Lot 2 Basal diluted with 5% of sand
Lot 3 Basal diluted with 10% of sand
Lot 4 Basal diluted with 20% of sand
The basal feed mixture is shown in Table 1. The sand used was a white build-
ers' sand of medium fine texture which blended well with the basal mixture. All
pigs were fed ad libitum by self-feeder in concrete floored pens and water was sup-
plied by automatic waterers.
1/ Wallace, Animal Nutritionist; Palmer, Meat Scientist; Carpenter, Associate
Meat Scientist; Combs, Associate Animal Nutritionist; and Houser, Graduate
Assistant, Animal Science Department. The assistance of B. R. Cannon and
L. S. Taylor, Swine Herdsman, and Jeff Jeter, Meats Laboratory Manager, is
- 2 -
Table 1. Composition of basal diet (17% protein).
Ingredient .. in Mixture
Yellow corn 77.35
Soybean meal (50%) 20.00
Defluorinated phosphate 1.50
Ground limestone 0.50
Iodized salt 0.50
Trace minerals-1 0.05
Vitamin premix2/ 0.10
Vitamin B12 supplement-/ 0.05
1/ Adds in ppm: manganese (29.6), iron (36.5), copper (2.5), cobalt (0.83),
zinc (42.0) and potassium (3.9).
2/ Merck vitamin supplement No. 1231. Contains 8000 mg. riboflavin, 14,720 mg.
d-pantothenic acid, 36,000 mg. niacin and 40,000 mg. choline chloride per
3/ Commercial Solvents Corporation Proferm-12. Contains not less than 12 mg.
vitamin B12 activity per lb.
The pigs averaged approximately 97 lb. initially. On November 11, 1965, all
pigs which had attained a liveweight of 190 lb. or more were slaughtered. On Dec-
ember 1, 1965, all remaining pigs were slaughtered. The pigs were dressed packer
style for carcass study. Carcass weights and measurements were taken after the
carcass had been chilled for 48 hours at 34-36 degrees F. Length of carcass was
obtained by a measurement from the anterior edgeof 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.
Full and empty stomach weights were obtained for all pigs at time of slaughter.
The stomach linings were carefully examined for ulcers and other abnormalities which
may have been related to the feeding of sand.
Results and Discussion
A summary of results is presented in Table 2. Pigs fed the basal mixture with
no sand added (Lot 1) gained 1.71 lb. per head daily and required 3.57 lb. of feed
per lb. of gain. All pigs fed sand (Lots 2, 3 and 4) gained slower than the basal
pigs (Lot 1). However, the reduction in gain was not directly related to the level
of sand added. The performance of pigs in Lot 2 (5% sand) appeared to be somewhat
out of step with the rest of the lots. An examination of individual pig performance
revealed that the rate of gain of two pigs in this lot was unaccountably slow. Al-
so, this lot was slaughtered at the lightest average weight of any of the lots, which
may have had some adverse influence on rate of gain. When feed conversions were
Table 2. Influence of dietary sand on the feedlot performance and carcass characteristics of
% dietary sand as diluent 0 5 10 20
Lot number 1 2 3 4
Number of pigs 23 23 23 23
Av. initial weight, lb. 97.7 97.7 97.2 97.6
Av. slaughter weight7 lb. 217.0 207.5 213.3 210.4
Av. daily gain, lb.- 1.71 1.57 1.66 1.51
Av. daily feed intake, lb. 6.10 6.09 6.59 6.87
Feed/lb. gain (+ sand) ----- 3.88 3.97 4.55
Feed/lb. gain (- sand) 3.57 3.69 3.57 3.64
Percent stomach tissue/ 0.65 0.64 0.62 0.66
Percent stomach contents- 1.15 1.23 1.41 1.16
Dressing perce tage-7 71.67 72.36 72.03 71.45
Percent liver2 1.82 1.71 1.60 1.66
Carcass length, in. 30.71 30.54 30.53 30.79
Backfat thickness, in. 1.41 1.37 1.44 1.37
1/ Pigs in Lot 1 gained significantly faster (P < .01) than pigs in Lots 2 and 4. Pigs in Lot 3 gained sig-
nificantly faster (P < .01) than pigs in Lot 4 and significantly faster (P < .05) than pigs in Lot 2.
2/ Expressed as a percentage of slaughter weight.
adjusted for the sand present in the feed, the requirements for all lots were not
greatly different. It appears that the pigs in Lots 2, 3 and 4 were simply trying
to overcome the presence of the sand in their diets by eating more feed.
Values obtained for percent stomach tissue and percent stomach contents revealed
no statistically significant differences. Pigs in Lot 3 showed an average of approxi-
mately 0.5 lb. more fill per pig than pigs in the other lots. This would tend to
give pigs from Lot 3 a very slight advantage in daily gains. The stomachs were ex-
amined for ulcers and other abnormalities that might possibly be related to the feed-
ing of sand. No ulcers were found in any of the pigs. Some erosion and inflammation
was observed, but the incidence was about equally divided among the pigs from the var-
Carcass measurements revealed no statistically significant differences due to
the feeding of sand. Backfat thicknesses were least for Lots 2 and 4, the slowest
gaining lots, whereas pigs getting 10% sand (Lot 3) showed the greatest amount of
back fat. The limited carcass data obtained suggested no clearcut picture as to
the effectiveness of dietary sand for improving carcass leanness.
A comparison of the relative performance of the barrows and gilts used in the
experiment is summarized in Table 3. Barrows gained 1.65 lb. per head daily, com-
pared to 1.58 for the gilts. Dressing percent and percent liver were very similar
for the two sexes. As in previous comparisons, gilts tended to yield longer car-
casses with less backfat.
Table 3. A comparison of the performance of barrows and gilts.
Sex Barrows Gilts
Number of pigs 44 48
Average initial weight, lb. 96.1 98.8
Average slaughter weight, lb. 212.5 211.7
Average daily gain, lb. 1.65 1.58
Dressing percent 71.82 71.93
Percent liver :1.68 1.71
Carcass length, in. 30.54 30.71
Backfat thickness, in. 1.43 1.37
A feeding experiment, involving 92 pigs which averaged 97 lb. initially, was
conducted to determine the effect of diluting a typical corn-soybean meal diet
with 5, 10 and 20% of white builders' sand.
Rate of gain was adversely influenced by the inclusion of sand, but the effect
was not a true linear expression relative to sand level. Pigs fed 5% sand did not
perform as well as pigs fed 10% sand. Possible explanations for this observation
are presented. In no case was the gain per unit of non-sand feed improved by the
inclusion of sand. With the exception of the 5% level of sand, it appeared that
sand stimulated feed intake, suggesting that the pigs were attempting to compensate
for the reduced energy intake by greater consumption.
Limited carcass measurements revealed no statistically significant effects of
the dietary sand.
Pigs consumed the feed mixtures readily, with no apparent ill effects, and feed
wastage was not a problem at the levels of sand studied.