Effects of using Different Levels of Crude Protein with or Without Probiotic Addition on Blood Indicators, Carcass Traits and Immunity Response

Abstract

Abstract This study was performed to statement the effect of different levels of dietary protein with or without probiotic addition on blood and immune indictors and carcass trait. Three hundred broiler chicks 308 were obtained from a commercial hatchery and reared for 35 d. At the beginning of the second week, the experiment was conducted on 240 birds 203.5 ± 7.25 g by using completely randomized design of a factorial arrangement (3 × 2). 3 levels of crude protein [standard level; 5% less than standard level (PR1); and 10% less than standard level (PR2)] and 2 levels of probiotic (0 and 0.5 g/kg). Results showed that birds fed probiotic had a higher (p<0.01) dressing percentage and breast relative weight than birds fed a diet without probiotic. While reducing dietary protein did not influence relative weight of breast and dressing percentage (p>0.05). The relative weight of the thigh, back, neck, wings, liver, and heart was not impacted by reducing protein, probiotic addition, or their interaction (p>0.05). The total cholesterol and glucose concentrations were significantly reduced in the birds fed a diet containing probiotic compared to the birds fed a diet without probiotic (p<0.01 and p<0.05 respectively). Neither protein nor probiotic effect on concentration of antibodies for Kumboro, Newcastle, and bronchitis infectious (p>0.05). There is interaction effect between protein levels and probiotic levels for antibody titer against bursal disease (p<0.05).