Growth performance, nutrient digestibility, fecal microbial diversity and volatile fatty acid, and blood biochemical indices of suckling donkeys fed multienzyme-supplemented diets

Abstract

Background Roughage and concentrate supplement contain large amounts of soluble non-starch polysaccharides (NSP). They not only reduce nutrient digestibility but also induce indigestibility in livestock. Moreover, starch particles embedded in the cereal protein matrix are not easily decomposed by starch-degrading enzymes. Glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase added to cereal diets can alleviate the adverse effects of NSP and cellulose. The current study determined the effects of adding glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase to the diet of 2-month-old suckling donkeys on their growth performance, apparent nutrient digestibility, fecal VFA and pH, fecal bacterial composition, and blood biochemical indices.Results On day 120 of the trial, fecal samples were collected from the rectum of donkeys for determining bacterial diversity, VFA content, and pH. Moreover, fresh fecal samples were collected from each donkey on days 110 and 115 to determine apparent digestibility. The multienzymes did not affect growth performance (P > 0.05) and apparent nutrient digestibility (P > 0.05) in the donkeys; however, they tended to increase (P = 0.0544) total height gain. At the study end, multienzymes increased (P < 0.05 or P < 0.01) the Observed species, ACE, Chao1, and Shannon indices by 10.56%, and 10.49%, 10.47%, and 5.01%, respectively. The multienzymes also increased (P < 0.05 or P < 0.01) the abundance of Firmicutes, Oscillospiraceae, Lachnospiraceae, Christensenellaceae, Christensenellaceae_R-7_group, and Streptococcus in feces and decreased (P = 0.0086) the abundance of Proteobacteria.Conclusions Conclusively, a multienzyme-supplemented basal diet for suckling donkeys can improve their total height gain and increase fecal microbial diversity and abundance.