FEED LIMITATION ON PERFORMANCE AND CARCASS CHARACTERISTICS OF FINISHING SWINE
Research Progress Report 78
September, 1963 Final
R. A. Pickett, J. R. Foster and D. H. Bache, Animal Sciences and Agricultural Economics Departments
Summary
Reducing feed intake to 5 pounds per pig per day at pig weights of 125 or 150 pounds resulted in slightly lower rate of gain, feed required per pound of gain, backfat thickness and dressing percent. None of these differences were statistically significant.
Feed costs were similar for full-fed and limit-fed pigs, but limit-fed pigs required a longer feeding period.
Limit Feeding
Limit feeding during the finishing period has been shown to reduce rate of gain and increase carcass leanness. Feed efficiency has also been improved in some cases by restricting feed intake during the finishing period. The purpose of this experiment was to further investigate the merits of limited feeding and to determine the effect of starting feed limitation at pig weights of 125 and 150 pounds.
Experimental Procedure
Two groups of 32 pigs each were allotted to two replications of four treatments each according to breeding, sex and weight. The first group averaged 74 pounds initially and the second group averaged 93 pounds. Treatments were as follows:
1--Self-feeder to market weight
2--Self-feeder to market weight
3--Self-feeder to 125 pounds; 5 pounds per
head per day to market weight
4-	-Self-feeder to 150 pounds; 5 pounds per
head per day to market weight
Each of the eight pens were approximately 4' x 15' with a slotted dunging area. They were allowed 6. 8 square feet per pig while on the self-feeder and 7.6 square feet per pig when the feeders were removed in treatments 3 and 4. Limit-fed pigs received their daily ration in two equal portions fed morning and evening on the floor.
From initial weight to approximately 125 pounds the pigs received a 16 percent protein ration which was a mixture of ground corn and a 40 percent protein supplement (Table 1). The protein level was reduced to 13 percent for the finishing phase of the experiment.
Table 1. Composition of supplement
Ingredient	Percent
Soybean meal (44%)	62.5
Meat and bone scraps	20.0
Dehydrated alfalfa meal	10.0
Dicalcium phosphate	3.2
Calcium carbonate	0.3
Salt, iodized	2.5
Premix a/	1.5
	100.0
a/ Premix supplied the following ingredients per pound of supplement: 2, 500 IU vitamin A, 500 IU vitamin D, 30 mcg. B12, 5 mg. riboflavin, 15 mg. pantothenic acid, 25 mg. niacin, 6.5 mg. copper, 95 mg. iron, 80 mg. manganese, 114 mg. zinc and 225 mg. arsanilic acid.
PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana