Effects of mixed orchard hay on bacterial diversity in the gastrointestinal tract of lambs

The effects of different ratios of mixed hay on the rumen and intestinal microflora of male dairy goats were studied using high-quality forage grass planted between rows in Weibei orchard, thereby providing a theoretical basis for the ecological breeding cycle model of “orchard – grass – livestock” in Weibei dry highland. (Method) Twenty-four 2 month-old healthy male goats of similar weight were selected and randomly divided into four groups with three replicates in each group and two goats in each replicate. The local traditional feeding method was used for the control group (CK), which included crop stalks (corn stalks and wheat stalks), alfalfa, and a small amount of field weeds. The three treatment groups consisted of a mixture of two types of hay (1 ꞉ 1), alfalfa + oat mixed hay (group Ⅰ), alfalfa + perennial ryegrass (group Ⅱ), and vetch + perennial ryegrass (group Ⅲ). Sampling and determination were conducted after 85 d of feeding. The bacterial composition of the rumen and cecum was determined using the 16S rDNA technique. (Results) The results showed that 1) group Ⅱ significantly increased the alpha diversity of the lamb intestinal flora (P < 0.05) compared with that of CK. Groups Ⅰ and Ⅲ had higher alpha diversity of lamb rumen bacteria, but this difference was not significant (P > 0.05). 2) For intestinal bacteria, the three orchard mixed hay combinations (groups Ⅰ, Ⅱ, and Ⅲ) had a significant effect on the relative abundance of Firmicutes compared with CK (P < 0.05). The relative abundance of Bacteroides in group Ⅱ was significantly higher than that in the other three groups (P < 0.05), and the relative abundances of Romboutsia and Clostridium in groups Ⅰ, Ⅱ, and Ⅲ were significantly higher than those in CK (P < 0.05). For rumen bacterial flora, the relative abundance of Bacteroides in group Ⅲ was significantly higher than that in the other three groups (P < 0.05), the relative abundance of Proteobacteria in group Ⅱ was significantly higher than that in the other three groups (P < 0.05), the relative abundance of Prevotella in group Ⅲ was significantly higher than that in the other groups (P < 0.05), and the relative abundance of Rikenellaceae RC9 in groups Ⅱ and Ⅲ was significantly higher than that in CK (P < 0.05). (Conclusion) In summary, feeding mixed hay from different orchards can increase the diversity of the gastrointestinal bacterial community, increase the abundance of beneficial bacteria in the gastrointestinal tract, and reduce the abundance of pathogenic bacteria in lambs, thereby keeping the lambs healthy. Alfalfa + perennial ryegrass was the best hay mixture.