Xylanase in diets for growing pigs and broiler chicks

The results of experiments designed to determine the effects of feeding graded levels of xylanase to 10-kg pigs (exp. 1) and 1-d old broiler chicks (exp. 2) are presented. Pigs received diet composed of corn, rye, wheat, and SBM for 28 d, whereas chickens were fed diet composed of rye, wheat, and SBM for 21 d. Six dietary treatments consisting of a control diet or control plus xylanase (in units kg(-1)) at 400, 800, 1600, 3200 or 32 000 were fed. Graded levels of xylanase had no effect on growth performance of 10-kg pigs. There were diet and age effects (P < 0.05) on digestibility of DM, CP, and Ca in pigs. Linear and quadratic responses (P < 0.05) in final weight, weight gain, and gain:feed of broiler chicks to graded levels of xylanase were observed in exp. 2. In exp. 2, the effect of xylanase became apparent (P < 0.05) at 800 U kg(-1); there were no differences in response to xylanase at 3200 and 32 000 U kg(-1). In conclusion, xylanase improved growth performance in 1-d-old broilers fed a diet composed of rye, wheat, and SBM but not in 10-kg pigs that received a diet composed of corn, rye, wheat, and SBM.