Abstract
Three feeding trials with a total of 120 pigs and one trial with 24 rats were conducted to evaluate the supplementation of barley-cotton-seed meal diets. Additions of riboflavin, pantothenic acid and vitamin B12 to diets containing alfalfa meal did not increase rate of gain or feed efficiency of pigs in trial 1. In trial 2, additions of riboflavin, niacin, pantothenic acid or vitamin B12 to all-plant diets (no alfalfa meal) increased rate of gain of pigs in the growing period (30 to 60 kg.) but not in the finishing period (60 to 90 kg.) and when analyzed overall there was no effect. In trial 1, substituting soybean meal or soybean meal plus meat and bone scraps for cottonseed meal did not improve performances of pigs fed diets containing 16% crude protein (dry matter basis). In trials 2 and 3, lysine supplementation of barley-cottonseed meal diets containing lower levels of protein increased rate of gain and apparently improved feed efficiency. A similar response was obtained with rats in trial 4. None of the carcass characteristics measured were influenced by lysine supplementation except the protein content was increased and the fat content decreased in samples of lean taken from the loin. Methionine supplementation was tested in trial 3 but did not improve rate of gain, feed efficiency or carcass characteristics.