Effects of weaning stress and Bacillus licheniformis intervention on rumen and intestinal microflora of Hu lambs

The aim of this experiment was to investigate the effect of early weaning on the diversity of rumen and intestinal microbiota in Hu lambs, and the role of adding Bacillus licheniformis to the ration in regulating weaning stress in lambs. Ninety newborn Hu lambs with natural delivery and birth weight close to (3.82 ± 0.46 kg) were selected for the experiment, and were randomly divided into three treatment groups: normal weaning group (CON group, 49 d weaning), early weaning group (EW group, 21 d weaning), and B. licheniformis group (BL group, fed with 60 mg/kg BW B. licheniformis, viable count ≥ 2 × 109 cfu/g, weaned at 21 d), were slaughtered at 26, 35, and 63 d, rumen contents, rumen fluid samples, and jejunal segments were collected for subsequent experiments. The results showed that weaning stress reduced the abundance and diversity of flora in the rumen and jejunal contents and mucosa of lambs in the short term, but allowed the flora to enter a steady state earlier without affecting the final flora abundance and diversity, early feeding of B. licheniformis helped to restore the abundance of some genera in the rumen and jejunum of lambs.