New feed additives for broiler diets to replace antibiotics, enhance gut immunity and reduce ammonia volatilization.

摘要

Two experiments were conducted to evaluate the use of feed additives against coccidia and to replace antibiotics and ionophores, the Yucca schidigera plant extract and exogenous enzyme (Avizyme RTM1502).; All broilers were fed with the same starter and grower diets. Diets changed in the content of additives according to the treatments. Chickens were vaccinated with Cocci-Vaccine (AdventRTM) at the first day and assigned to vaccinated treatments. All broilers, except those of the negative control (Trt 1) were challenged with standard oral inoculums of sporulated oocysts and lesion scores evaluated. Body weight gain, feed intake, and feed conversion ratio were recorded. Oocyst identification was performed and oocyst count was done at 7 days post challenge and Anti-coccidial Index was calculated.; The two feed additives evaluated are not better than the antibiotics or ionophores used for comparison and their responses to enhance immunity against coccidia are very variable.