Digestibility of nitrogen and certain amino acids in soybean meal determined with intact and caecectomized roosters

Ten samples of soybean meal were collected from various agencies across the country. These were precision fed to intact or caecectomized roosters, separately. Digestibility of dry matter, nitrogen, lysine, methionine and tryptophan were determined using TME bioassay. The dry matter digestibility (DMD) ranged from 63.42 ± 0.12 to 70.85 ± 0.27% and 57.04 ± 0.27 to 69.79 ± 0.88%, in intact and caecectomized birds, respectively. In caecectomized roosters the DMD was found to be significantly lower than that of intact counterpall. The digestibility of nitrogen, lysine, methionine and tryptophan ranged from 64.53 ± 1.15 to 82.32 ± 0.59, 70.00 ± 1.17 to 89.41 ± 0.96, 85.51 ± 0.75 to 95.88 ± 0.83, and 85.00 ± 0.71 to 94.03 ± 0.45%, with intact roosters and from 64.48 ± 0.70 to 82.29 ± 0.72, 69.71 ± 1.19 to 89.34 ± 0.62, 85.32 ± 0.35 to 94.71 ± 0.59 and 84.89 ± 0.19 to 93.82 ± 0.75% with operated roosters, respectively. There was no significant difference in digestibility of nitrogen and amino acids between intact and operated birds in the samples. It was observed that the caecectomy had no influence on the digestibility of nitrogen, lysine, methionine and tryptophan except on DMD.