APPARENT ILEAL DIGESTIBILITIES OF AMINO-ACIDS IN NEWLY WEANED PIGS FED DIETS WITH PROTEASE-TREATED SOYBEAN-MEAL

Apparent ileal digestibilities of amino acids were determined in pigs fed cornstarch-based diets with untreated or protease-treated soybean meal as the protein source. Sixteen pigs were fitted with a modified p ost valve T-cecum cannula on d 14, 15, and 16 after birth and then ret urned to their sows until d 20 when they were weaned. Twelve of the pi gs were selected for the study, which was conducted according to a two -period balanced change-over design. Treatments consisted of soybean m eal that was I) untreated (SBM), 2) processed by incubation (1:2 wt/vo l distilled water adjusted to pH 4.5, for 16 h at 50 degrees C; CI-SBM ), 3) sprayed with protease (supplied at 1 mu L/g of soybean meal; PS- SBM), and 4) processed by incubation, as for CI-SBM, with protease in the water at the rate of 1 mu L/g of soybean meal (PI-SBM). Each perio d consisted of 5 d of adaptation to diets followed by three 8-h collec tion periods (total of 24 h) that alternated with 8-h periods in which digesta were not collected. Apparent CP digestibilities were similar (P > .05) at 70.4, 72.4, 65.2, and 70.3% for the SBM, CI-SBM, PS-SBM, and PI-SBM diets, respectively. Corresponding amino acid digestibiliti es were also similar (P > .05), ranging from 62.5, 67.5, 57.9, and 65. 0% for alanine to 83.5, 83.4, 78.7, and 84.1% for arginine. Apparent d igestibilities were less (P < .05) for Period 1 (on d 7 after weaning) than for Period 2 (on d 16 after weaning). In conclusion, protease tr eatment of soybean meal had no effect on ileal digestibilities of CP a nd amino acids in newly weaned pigs.