Compound probiotics alleviating aflatoxin B₁ and zearalenone toxic effects on broiler production performance and gut...

In order to alleviate toxic effects of aflatoxins B₁ (AFB₁) and zearalenone (ZEA) on broiler production performance and gut microbiota, three kinds of compound probiotics (CP) were selected. The optimal ratios of Bacillus subtilis, Lactobacillus casei and Candida utilis in broiler diets were 7, 5 and 6 log CFU/g for ZEA biodegradation (CP1); 6, 7 and 7 log CFU/g for AFB₁ biodegradation (CP2); 7, 6 and 7 log CFU/g for ZEA + AFB₁ biodegradation (CP3). A total of 350 1-day-old Ross broilers were randomly divided into 7 groups. Group A was the basal diet, group B-G contained ZEA, AFB₁, ZEA + AFB₁, ZEA + CP1, AFB₁+CP2, ZEA + AFB₁+CP3, respectively. The experiment showed that AFB₁ or AFB₁+ZEA significantly decreased broiler production performance, damaged liver and jejunum, increased mycotoxin residues in broiler body; however, three kinds of compound probiotics additions could alleviate mycotoxin negative effects on the above parameters (p < 0.05). The gut microbiota analysis indicated that AFB₁+ZEA increased jejunal microbial richness, but which were decreased to almost the same level as the control group by CP3 addition. CP3 addition significantly increased jejunal Firmicutes and Lactobacillus aviarius abundances. The correlative analysis showed that gut Lactobacillus aviarius abundance was positively correlated with average daily gain (ADG) of broilers (p < 0.05), while AFB₁+ZEA addition decreased its relative abundance, indicating that CP3 addition increased broiler growth by increasing Lactobacillus aviarius abundance. AFB₁ and ZEA residues in broiler body were negatively correlated with the gut beneficial bacterial abundances (p < 0.01), but positively correlated with the potentially harmful bacterial abundances (p < 0.05), which inferred that CP3 addition could decrease mycotoxin residues through positively regulating gut relative bacterial abundances. In conclusion, compound probiotics could keep gut microbiota stable, degrade mycotoxins, alleviate histological lesions, increase production performance and reduce mycotoxin toxicity for broilers.