نعمت ضیائی

A study was conducted to compare the effects of different levels of a suspension of Scenedesmus Microalgae (SM) on growth, immune response, carcass traits, and some blood parameters of broilers. Two hundred 1-d-old broiler chicks were randomly assigned to each of 5 dietary treatments. Treatments consisted of: T1 (100% drinking water), T2 (50% drinking water+50% SM), T3 (25% drinking water+75% SM), T4 (100% SM) and T5 [(Basal diet (BD) + 2.5 mg Virginamycin kg-1 diet)] with 4 replicate cages of 10 birds each. The birds receiving T3 and T4 had higher feed intake compared with the control and antibiotic groups at 1-10 days (P< 0.001). Water replacement by 100% SM increased body weight (P< 0.001) and reduced feed conversion ratio (P< 0.05) in broilers. Inclusion of 100% SM increased SRBC antibody titer in primary and secondary responses compared to that of the control group. (P< 0.05). The birds receiving T4 had lower serum content of triglycerides and cholesterol compared with the control group (P< 0.05). Chickens at the T4 group showed higher relative breast weight compared with the control group (P< 0.05). It was concluded that SM at the levels of 75 and 100% can improve growth performance, immune responses, and some blood parameters of broiler chicks.