ABSTRACT
Coccidiosis is a well-known poultry disease that causes the severe destruction of the intestinal tract, resulting in reduced growth performance and immunity, disrupted gut homeostasis and perturbed gut microbiota. Supplementation of probiotics were explored to play a key role in improving growth performance, enhancing innate and adaptive immunity, maintaining gut homeostasis and modulating gut microbiota during enteric infection. This study was therefore designed to investigate the chicken gut whole microbiota responses to Bacillus subtilis (B. subtilis) probiotic feeding in the presence as well as absence of Eimeria infection. For that purpose, 84 newly hatched chicks were assigned into four groups, including (1) non-treated non-challenged control group (CG - ET), (2) non-treated challenged control group (CG + ET), (3) B. subtilis-fed non-challenged group (BS - ET) and (4) B. subtilis-fed challenged group (BS + ET). CG + ET and BS + ET groups were challenged with Eimeria tenella (E. tenella) on 21 day of housing. Our results for Alpha diversity revealed that chickens in both infected groups (CG + ET and BS + ET) had lowest indexes of Ace, Chao 1 and Shannon, while highest indexes of Simpson were found in comparison to non-challenged groups (CG - ET and BS - ET). Firmicutes was the most affected phylum in all experimental groups following Proteobacteria and Bacteroidota, which showed increased abundance in both non-challenged groups, whereas Proteobacteria and Bacteroidota affected both challenged groups. The linear discriminant analysis effect size method (lEfSe) analysis revealed that compared to the CG + ET group, supplementation of probiotic in the presence of Eimeria infection increased the abundance of some commensal genera, included Clostridium sensu stricto 1, Corynebacterium, Enterococcus, Romboutsia, Subdoligranulum, Bacillus, Turicibacter and Weissella, with roles in butyrate production, anti-inflammation, metabolic reactions and the modulation of protective pathways against pathogens. Collectively, these findings evidenced that supplementation of B. subtilis probiotic was positively influenced with commensal genera, thereby alleviating the Eimeria-induced intestinal disruption.
ABSTRACT
AIM: This study aimed to determine the potential prophylactic efficacy of probiotic individually and/or in combination with anti-coccidial drug on the performance and immunity of broilers under an induced coccidial infection over a 28-day of experimental trial. METHODS: One hundred and eighty 1-day-old Cobb broiler chicks were randomly divided into five groups, included control group (CG), control positive group (CPG), probiotic-treated group (Prob), diclazuril-treated group (Dic), and probiotic + diclazuril-treated group (Prob + Dic). On day 21 of age, all birds, except group CG, were orally inoculated with 1 ml of tap water containing 25,000 Eimeria tenella sporulated oocysts. RESULTS: Our results showed that the probiotic treatment did not influence pre-challenge body weight, feed intake and feed conversion ratio (FCR). During the post-challenge period, chickens in groups probiotic and diclazuril individually and in combination exhibited higher body weight and lower (better) FCR, reduced oocyst shedding (throughout the day four, five, six and seven post-infection), cecal lesions and mortality compared with control positive chickens. Moreover, Compared to CPG group, Prob + Dic group showed increased (p < 0.05) serum levels of interleukin-10 (IL-10) and immunoglobulin M (IgM) and decreased the concentrations of interferon gamma (IFN-γ). On the other hand, individual treatment with probiotic exhibited highest serum levels of IL-10 and IgM, while diclazuril alone increased the blood concentrations of IL-10 and decreased the levels of IFN-γ compared to control positive group; however, there was no significant effect of Prob on IFN-γ, Dic on IgM and all groups on interleukin-17. CONCLUSION: In conclusion, supplementation of probiotic, with and/or without anti-coccidial drug, enhances immunity and inhibits the negative effects of Eimeria infection. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reveals the anti-coccidial mechanisms of probiotic in the presence and absence of anti-coccidial drug in preventing the coccidia infection.
