بررسي اثر سطوح مختلف پروبيوتيك بر فاكتورهاي خوني عملكرد و خصوصيات لاشه جوجه هاي گوشتي تحت شرايط تنش گرمايي حاد

Evaluation of the effect various levels of probiotic on blood factors, performance and carcass characteristics of broiler chicks under acute heat stress

Three hundred male Ross chicks were randomly distributed among three groups of 100 chicks with four replicates per group. First group (control ) received a diet without any antibiotic and coccidiostate. Two other groups received, 0.05% and 0.1% probiotic Bioplus 2B in diets. The results indicated that various levels of probiotic Bioplus 2B had no significant effect on body weight and feed intake in comparison to the control. However, body weight increased insignificantly during 4-6 weeks of age. Diet supplemented with probiotic significantly improved feed conversion ratio of chicks during 4-6 weeks of age(P<0.05). The diet supplemented with 0.1% probiotic significantly increased WBC count and resulted in decreased NIL when compared to the control (P<0.05). Addition of various levels of probiotic to the diet had insignificant effect on antibody titer against SRBC and Newcastle disease antigen in relation to the control. The serum cholesterol level of chicks fed 0.1% probiotic supplemented diet was significantly lower than the control group(P<0.05). The inclusion of 0.1% probiotic significantly improved carcass yield (P<0.05). Percentage of abdominal fat was not significantly different between probiotic supplemented group and control group.