Effect of biotin and(or) lysine additions to corn-soybean meal diets on the performance and nutrient balance of growing pigs.

Supplementation of a basal corn-soybean meal diet with 0 or .2% L-lysine and 0, .25 or .55 ppm biotin produced six dietary treatments in a factorial arrangement. Pig performance, post-weaning scour scores, plasma urea N (PUN) levels, N and energy balance and liver pyruvate carboxylase activity (PC) were response criteria. Crossbred pigs were fed from weaning at 4 wk of age (8.0 kg) to market weight in performance trials utilizing 552 pigs in the 35-d starter period and 384 pigs in the subsequent grower (about 21 to 50 kg) and finisher (about 50 to 95 kg) periods. Pigs remained on their respective dietary treatments for the entire experiment. Energy and N balance trials were conducted utilizing 36 barrows from the grower period (avg 44.7 kg) and 36 barrows from the finisher period (avg 90.3 kg) of the performance study. Barrows were sacrificed following completion of the 6-d collection periods to measure liver PC activity. The basal starter diet contained 17.0% crude protein (CP), 86% lysine and .22 ppm biotin. Increasing the corn:soybean meal ratio reduced the dietary levels of CP, lysine and biotin to 14.8%, .69% and .19 ppm for the basal grower diet and to 11.1%, .50% and .17 ppm, respectively, for the basal finisher diet. Lysine supplementation improved (P less than .05) average daily feed intake and average daily gain for all periods, gain:feed ratios for the starter and grower periods and reduced (P less than .01) PUN levels at the end of the starter and finisher periods.(ABSTRACT TRUNCATED AT 250 WORDS)