Comparison of the sensitivities of growth and digestibility studies using intact, cecectomized, and cannulated...

The sensitivity of several bioassays was determined using soybean meal and two autoclaved soybean meals. Chick growth study results revealed that a four percent difference in weight gain was sufficient to show statistical significance (P less than .05) between the diets. Lysine quantities and digestibility values were compared using excreta obtained from intact (excreta collected on mats or in bags), cecectomized. and ileal-cannulated roosters. A 30% difference in lysine quantity in the excreta (collected on mats) was required to detect statistically significant effects of different diets fed to intact birds. Using intact birds (excreta collected in bags), cecectomized, and cannulated birds, differences in lysine quantity of 41, 42, and 67% were required to show statistically significant effects. Results showed that altering birds did not significantly change lysine values obtained nor reduce variability among birds (P greater than .05).