Astragalus polysaccharide and Agaricus Blazei polysaccharides improve growth performance, meat quality and health status of lambs via rescheduling the rumen microbiota

From the paper

Abstract

Since the banning of antibiotics, the use of green feed additives has become crucial for the healthy farming of mutton sheep. Astragalus polysaccharides (APS) and Agaricus Blazei polysaccharides (ABP) exhibit various functions such as antioxidation, immunomodulation, and meat quality improvement. Therefore, this study aimed to investigate the effects of APS and ABP supplementation on growth performance, blood biochemistry, immunity, meat quality, ruminal microbiota, and rumen epithelial gene expression in lambs. Thirty-six 2.5-month-old weaned male lambs (weighing 20.85 ± 1.62 kg) were randomly divided into three groups (n = 12). They were as follows: 1) CON group (basal diet), 2) APS group (basal diet + 0.30 % APS), and 3) ABP group (basal diet + 0.20 % ABP). All lambs were reared on a large, well-managed farm in China, with each group housed in separate pens. The pre-feeding period was 10 d and the treatment period was 120 d. Dietary APS and ABP increased the final body weight, Total VFA and acetate concentration in the rumen, and serum levels of glucose (GLU), IgG, and IgM in lambs (p < 0.05). In addition, the ADG and ruminal butyrate concentration were higher in the ABP group (p < 0.05). Dietary ABP increased muscle C18:1n9t and unsaturated fatty acid (UFA) contents and reduced muscle drip loss, whereas APS increased C22:2 and C20:5n3 contents and decreased saturated fatty acid (SFA) contents (p < 0.05). About ruminal microbiota, the relative abundances of unclassified_Bacteria and Spirochaetota were lower in the ABP and APS groups than in the CON group, while that of Desulfobacterota was reduced only in the ABP group (p < 0.05). The relative abundance of Rikenellaceae_RC9_gut_group was decreased in both treatment groups, whereas that of unclassified_Prevotellaceae was decreased in the APS group (p < 0.05). Furthermore, dietary ABP and APS increased the expression of MCT1 and NHE2, both of which were positively correlated with Rikenellaceae_RC9_gut_group. In summary, the addition of APS and ABP to the diet can improve the growth performance, meat quality, rumen fermentation, and microbiota of lambs. It is worth noting that the overall effect of ABP is superior to that of APS.