Objective   Effects of substituting refined meal in forage with beer brewing residues on the digestion and microbial diversity of rumen of Hu sheep were studied to explore the feasibility of utilization of the waste material.

  Methods   Twenty-four healthy Hu sheep with similar body weight of (15.90±0.36) kg were randomly divided into 4 groups. The animals were fed with a basic forage that consisted of corn and soybean meal at 36% as control (Group I) or one that used beer lees to replace 1/3 (Group II), 2/3 (Group III), or total (Group IV) of the meal. At end of the feeding period, 3 sheep were randomly selected from each group to determine the digestion indicators and microbial diversity in the rumen fluid.

  Results   (1) None of the substitutions showed significant differences on volatile fatty acids, pH, ammonia nitrogen, or acetic acid in the rumen (P＞0.05), but significantly higher on isobutyric acid in Group II than others (P＜0.05). (2) At phylum level, no significant differences on richness of diversity were introduced by the substitutions on Firmicutes, Bacteroidetes, Proteobacteria, Synergistetes, Fibrobacteres, Actinobacteria, Epsilonbacteraeota, Spirochaetes, and Tenericutes (P＞0.05). However, the diversity of Verrucomicrobia in Group I was significantly lower (P＜0.05). At genus level, the beer lees replacements in the forage did not significantly alter the diversity on Prevotella, Succiniclasticum, Intestinimonas, Tyzzerella, Ruminococcus, Faecalicatena, Pseudobutyrivibrio, and Hungateiclostridiumhad (P＞0.05).

  Conclusion  The replacement of the refined meal in forage with beer lees reduced the relative richness of Verrucobacteria but did not significantly changed the microbial community structure and diversity of the rumen fluid.