Effects of amino acid supplementation of sorghum based diets for the growing pig
Abstract
Six experiments utilizing 284 pigs were conducted to determine the effects of amino acid supplementation of sorghum-soybean meal diets for growing pigs. Experiment 1 diets consisted of: (1) basal diet, 13.8% protein; (2) threonine balanced diet + .18% lysine; (3) threonine deficient diet + .30% lysine; and (4) as three + .07% threonine. Pigs fed diet 4 gained faster (P<.05) and were more efficient than pigs fed diet 3. The amino acid analysis in experiment 2 and 3 indicated isoleucine was second limiting. Test diets were as follows: (1) basal diets, 15.99% protein; (2) isoleucine balanced diet + .11% lysine; (3) isoleucine deficient diet + .166% lysine; and (4) as three + .05% isoleucine. Results of experiment 2 and 3 showed no differences in growth and feed efficiency for all diets except for the third experiment. During the last 14 days of this study, pigs fed diet 2 grew faster and were more efficient in their gain/feed ratio (P<.05). No differences resulted in PUN values in experiment 2. Test diets for experiment 4 consisted of: (1) basal diets, 13.36% protein; (2) threonine balanced diet + .18% lysine; (3) threonine deficient diet + .32% lysine; and (4) as three + .061% threonine. Pigs fed the basal diet grew faster (P<.05). Diets used in experiment 5 and 6 were: (1)basal sorghum diet, 9.18% protein + .25% lysine; (2) basal + .128% isoleucine and .25% lysine; (3) basal + .128% isoleucine with .25% lysine and .039% threonine; and (4) as three + .266% methionine. Experiment 5 revealed that pigs fed diet 3 grew faster (P<.05) and produced the lowest PUN values. Experiment 6, a metabolism study, again showed that diet 3 was superior to the other three treatments as these pigs retained the most nitrogen.