Feeding of dried sweet orange (Citrus sinensis) peel on humoral immune response of broiler chickens

Abstract

An experiment was conducted to evaluate the effect of dried sweet orange ( Citrus sinensis ) peel (DCSP) on humoral immune response of broiler chickens. Four hundred 1-day-old Ross 308 broilers were distributed according to a completely randomized design into five treatments with four replicates of 20 chicks each. The following five dietary treatments were applied: control group with 0% DCSP; diet containing 1.5% DCSP from 1 to 21 days of age (starter phase) and from 1 to 42 days of age, respectively; and diet containing 3% DCSP from 1 to 21 days of age (starter phase) and from 1 to 42 days of age, respectively. The DCSP treatments influenced positively total anti-SRBC and IgG titers on days 28 and 42, whereas no differences were found for IgM titer. The anti-NDV titers were not affected by diets; conversely, the anti-AIV titers were different among treatments. The anti-IBD titers were different on days 14 and 42 among diets, whereas anti-IBV titers were not influenced by treatments. Average white blood cell, heterophil, lymphocyte, and monocyte counts, as well as heterophil/lymphocyte ( H / L ) ratio, were different among treatments. The findings suggested that the dietary inclusion of dried Citrus sinensis promoted some effects on the immune humoral response of chickens; however, these effects were not completely effective to protect birds from the main diseases.