Probiotics and Achyranthes bidentata Polysaccharides Improve Growth Performance via Promoting Intestinal Nutrient Utilization and Enhancing Immune Function of Weaned Pigs

SIMPLE SUMMARY: It is frequent to see that in-feed antibiotics are added to piglets diets because of their enteric problems after weaning. However, in-feed antibiotics have been forbidden to used in livestock production since 1 July 2020 in China. Therefore, it is urgent to develop some promising alternatives to in-feed antibiotics. Probiotics and plant extracts are considered to be the potential replacements, which have been studied or applied in animal production. In our study, we found that probiotic or Achyranthes bidentata polysaccharides used alone or in combination, the combination augmenting the positive effect more than the independent supplement, could improve piglets’ growth performance via promoting intestinal nutrient digestion and absorption and enhancing immune funtion, and the beneficial role was comparable to that of the selected in-feed antibiotics. ABSTRACT: The experiment aimed to investigate the effects of probiotics and Achyranthes bidentata polysaccharides on the growth performance, nutrients digestibility, and immune function of weaned pigs. One hundred and twenty weaned pigs (about 7 kg BW, 23 ± 2 d) were allotted to five dietary treatments (CON: antibiotics-free basal diet; ANT: CON + antibiotics; PRO: CON + probiotics; ABPS: CON + Achyranthes bidentata polysaccharides; P-ABPS: PRO + ABPS) for a 28-day trial. Compared with CON, pigs in ANT, PRO, ABPS, and P-ABPS had greater (p < 0.05) ADG, ATTD of CP and GE, serum ALB, IgA and IL-2, duodenal intraepithelial lymphocyte, ileal VH and jejunal mucosa sIgA, but lower (p < 0.05) fecal scores, serum BUN, and IL-1β. Meanwhile, ANT, PRO, ABPS, and P-ABPS exhibited similar beneficial roles on growth performance, nutrients digestibility, serum parameters, and immune function. Interestingly, P-ABPS effects were similar to those obtained with ANT rather than with PRO or ABPS. In conclusion, Dietary PRO or ABPS used alone or in combination (P-ABPS), the combination augmenting the positive effect more than the independent supplement, could improve piglets’ growth performance via promoting intestinal nutrient digestion and absorption and enhancing immune function, indicating it had the potential to act as an alternative to in-feed antibiotics used in piglet diets.