Efficacy of Dietary Cottonseed Bioactive Peptides Compared to Diclazuril or Salinomycin on Reducing Adverse Effects of Coccidiosis Challenge in Broiler Chickens.

Abstract

BACKGROUND: Bioactive peptides present antimicrobial, antioxidative and immunomodulatory activities with beneficial effects on broiler chickens. OBJECTIVES: This experiment was conducted to examine the influence of dietary supplemental cottonseed bioactive peptides (CBP) on growth performance, oocysts per gram of faeces (OPG), intestinal morphology, immune responses and interleukin-6 (IL-6) gene expression in broilers exposed to coccidial infection. METHODS: A total of 420 broiler chicks (Ross 308) were assigned to seven dietary treatments in a completely randomized design during 10-45&#xa0;days of age. Experimental treatments included: (1) CON+, broiler chickens without challenge; (2) CON-, birds challenged with coccidiosis; (3-5) the CON- birds fed diets containing 4&#xa0;g/kg, 5&#xa0;g/kg or 6&#xa0;g/kg CBP, respectively; (6) the CON- birds fed diets containing 0.2&#xa0;g/kg diclazuril; (7) the CON- birds fed diets containing 0.5&#xa0;g/kg salinomycin. RESULTS: Infection alleviated daily feed intake and growth of broilers fed a basal diet during 31-38 days of age (p&#xa0;<&#xa0;0&#xb7;05), which ameliorated after supplementation of 6&#xa0;g/kg CBP (p&#xa0;<&#xa0;0.05). Dietary 4 or 6&#xa0;g/kg CBP, diclazuril or salinomycin compensated for the impairment in the feed conversion ratio of Eimeria spp. challenged broilers during 31-45 days of age (p&#xa0;<&#xa0;0.05). Coccidiosis challenge increased OPG; however, the OPG value decreased when the diet contained CBP or anti-coccidiosis drugs (p&#xa0;<&#xa0;0.05). Antibody titer against sheep red blood cells improved in challenged birds fed 6&#xa0;g/kg CBP (p&#xa0;<&#xa0;0.05). CONCLUSIONS: Dietary CBP decreased the negative effects of coccidiosis, whereby supplemented birds had similar immune responses or even better growth performance than birds receiving anticoccidials.