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

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 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 g/kg, 5 g/kg or 6 g/kg CBP, respectively; (6) the CON- birds fed diets containing 0.2 g/kg diclazuril; (7) the CON- birds fed diets containing 0.5 g/kg salinomycin.

RESULTS

Infection alleviated daily feed intake and growth of broilers fed a basal diet during 31-38 days of age (p < 0·05), which ameliorated after supplementation of 6 g/kg CBP (p < 0.05). Dietary 4 or 6 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 < 0.05). Coccidiosis challenge increased OPG; however, the OPG value decreased when the diet contained CBP or anti-coccidiosis drugs (p < 0.05). Antibody titer against sheep red blood cells improved in challenged birds fed 6 g/kg CBP (p < 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.