Document Type : Research Paper
Former M. Sc. Student, Department of Animal Science, College of Agricultural Science, University of Guilan, Rasht, Iran. P.O.Box: 58643-41889
Associate Professor, Department of Animal Science, College of Agricultural Science, University of Guilan, Rasht, Iran. P.O.Box: 58643-41889
An experiment was conducted on 240 one-day old Ross 308 broiler chicks using a completely randomized design in a 2×3 factorial arrangement with two levels of nano-adjuvant (with and without) and three levels of dietary protein (low, medium and high) during a 42 d experimental period. The main effect of protein density on feed intake was significant during the starter and grower periods (P<0.05). With regard to body weight gain, the main effect of protein density was significant in the starter, grower and whole experimental periods (P<0.01). Among the main and interaction effects, only the main effect of protein density on feed conversion ratio in the starter period was significant (P<0.01). The effect of protein density was also significant on the relative weights of carcass, legs, abdominal fat pad and bursa of Fabricius (P<0.05). The main effects of the protein density and nano-adjuvant for total anti-SRBC and IgG titers were significant at day 28 (P<0.05). Cell immunity in response to PHA-P injection was not affected by the factors. As an overall conclusion, diets with high protein density showed a better ability in improving the performance and immune response of broiler chicks compared to the diets with medium and low protein density. Also, the results showed some advantages for nano-adjuvant in humoral immune response stimulation.