Abstract

This experiment was conducted to evaluate the potential of yarrow in comparison with probiotic as growth promoter on performance, immune responses, and some biochemical and hematological parameters in broiler chicks. One hundred and ninety two day-old mix broiler chicks (Ross 308) were randomly assigned to four treatment groups (control, probiotic 15 mg/kg Protoxin™, and yarrow powder of 5 and 10 g/kg of diet). Four floor pen replicates of 12 chicks were randomly allocated to each treatment. Body weight, feed intake, and feed conversion ratios were recorded at 14, 28 and 42 d. On day 42 blood samples were collected in heparinized and none-heparinized vials from the wing vein and hematological and biochemical parameters were determined, respectively. Albumin to globulin and heterophil to lymphocyte ratios were also calculated. Antibody titers against Newcastle and Influenza viruses and sheep red blood cell (SRBC) were measured at 24 and 28 d of age, respectively. Results showed that body weight of broilers significantly (P<0.05) increased in probiotic treatment and decreased in 10 g/kg yarrow. Feed intake of broilers not significantly tended to decrease in control but feed conversion was not affected by dietary treatments. Most of the carcass characteristics of broilers slaughtered at 42 d were not influenced by treatments but abdominal fat pad significantly reduced (P<0.05) in probiotic group compared to control birds. Serum triglyceride level in probiotic and dietary yarrow groups was significantly lower than control birds (P<0.05). Other blood parameterswere not statistically affected by dietary treatments. No significant impact of additives was observed on humoral immune responses but H/L ratio decreased markedly in birds fed probiotic. The current results suggest that addition of yarrow powder seem not to have a positive influence on growth performance and failed to elevate immune responses thus, it could not be considered as a natural growth promoter for broiler chicks.

Key words: Broiler, yarrow, probiotic, immunity, serum biochemistry, blood hematology.