This study was carried out to investigate the effects of probiotics and Chinese medicine polysaccharides (CMP) on carcase characteristics, meat quality, muscle fibre type and intramuscular fat deposition in lambs. Forty female lambs with 4-5 months old and 21.69 ± 0.46 kg were randomly divided into four groups as follows: control, probiotics, CMP and probiotics + CMP groups. The results showed that supplemental probiotics increased carcase yield, the percentage of abdominal fat and perirenal fat of lambs, the levels of moisture and intramuscular fat in Longissimus thoracis (LT) muscle and the mRNA expression of MyHC I but decreased the value of shear force, lightness (L*) and yellowness (b*) and the percentage of heneicosanoic acid (C21:0) in LT muscle compared with the control group (p < .05). Supplemental CMP declined the value of b*, the percentage of C21:0 and mRNA expression of MyHC I but enhanced the percentage of arachidonic acid (C20:4N6) and the content of moisture in LT muscle compared with the control group (p < .05). The percentage of abdominal fat and perirenal fat, the value of meat redness (a*) and the mRNA expression of MyHC IIx were higher, while pH_24 h value was lower in lambs fed probiotics + CMP diets than those fed control diets (p < .05). All groups increased muscle fibres density of lambs compared with the control group (p < .05). Current results suggested that supplemental probiotics can affect muscle fibre characteristics, increase intramuscular fat deposition and improve meat quality. Probiotics should be a promising feed additive for production of high-quality lamb meat.

This study aimed to investigate the effects of Pogostemon cablin essential oil (PEO) on rumen development in heat-stressed beef cattle. Eighteen male Jingjiang cattle were randomly assigned to two groups and fed a diet containing PEO at 0 mg/kg (Control) and 50 mg/kg in the feed concentrate (n = 9 per group). The rumen fluid samples had lower ammonia nitrogen and higher cellulase activity, propionate and total volatile fatty acids concentrations in the 50 mg/kg PEO group. Compared with the control group, 50 mg/kg dietary supplementation with PEO increased crude protein and neutral detergent fiber digestibility. Additionally, the ruminal tissue papilla height, the papilla surface area, and the activities of glutathione peroxidase, total superoxide dismutase, and total antioxidant capacity were also higher, while the malondialdehyde content was lower for the heat-stressed cattle in the 50 mg/kg PEO group. Furthermore, PEO increased the average optical density values and mRNA expression of zonula occludens-1 (ZO-1) and occludin (p < 0.05). Transcriptomics analysis of the rumen epithelium showed that PEO upregulated the expression levels of genes related to tight junction proteins and the DNA replication/repair pathways, while it downregulated pro-apoptotic genes. In summary, dietary PEO supplementation improved nutrient digestibility, enhanced rumen antioxidant capacity, and promoted the repair of damaged rumen epithelium in heat-stressed cattle, indicating that PEO exerts a prominent protective effect on rumen function.

Puerarin has been suggested to improve ruminant productivity, but its effects on rumen fermentation and rumen microbiota in sheep remain insufficiently understood. In this study, Hu sheep were fed diets supplemented with 0, 50, 100, 200, 400, or 800 mg/kg puerarin for 30 d to evaluate growth performance, apparent nutrient digestibility, serum biochemical and antioxidant indices, rumen fermentation, and rumen microbial community structure. Puerarin supplementation improved growth performance, with the 100 mg/kg group showing the greatest average daily gain. Acid detergent fiber digestibility was also significantly increased in the 100 mg/kg group. In the rumen, microbial crude protein concentration was significantly increased in the 100 and 400 mg/kg groups, propionate concentration was significantly increased in the 50 and 100 mg/kg groups, and the acetate-to-propionate ratio was significantly decreased in the 100 mg/kg group. In serum, albumin and glucose concentrations were significantly increased at appropriate supplementation levels, whereas malondialdehyde was reduced in the 100 mg/kg group but increased in the 800 mg/kg group. 16S rRNA sequencing showed limited effects on overall bacterial diversity, but changes in specific rumen microbial taxa and predicted microbial functions were observed. Collectively, these findings suggest that dietary puerarin, particularly at 100 mg/kg, may improve growth performance in Hu sheep, at least in part, through improving rumen fermentation.