Antibiotics used in feed as a growth promoter has become increasingly controversial, and is banned in some countries. Thus, finding safe and effective alternatives to traditional antibiotics will allow swine producers to maintain competitive advantages provided by antibiotics. 

As the most stressful phase in the life of pigs, weaning is commonly associated with post-weaning syndrome including diarrhea, growth retardation and intestinal barrier disruption. 

Researchers from the Institute of Subtropical Agriculture (ISA) of the Chinese Academy of Sciences found that yeast glycoprotein (YG) affected growth performance, intestinal mucosal morphology, immune response and colonic microbiota in weaned piglets. 

A total of 240 weaned piglets (d 23 ± 2) were randomly allocated to an antibiotics group (25% Quinocetone 200 mg/kg and 4% Enduracidin 800 mg/kg of the basal diet), and a YG group (800 mg/kg YG of the basal diet), respectively. The researchers found that piglets fed diets containing YG increased average daily gain and decreased F/G (P < 0.05) when compared with the antibiotics group. 

Histological evaluations showed that YG contributed to the improvement of the intestinal development via increasing villous height (P < 0.05) and the villous height to crypt depth ratio (P < 0.01), and decreasing crypt depth (P < 0.01) and villous width (P < 0.05) in the ileum. 

They also found that YG was conducive to the improvement of intestinal development via upregulating the m-RNA expression of occludin gene (P < 0.05) in the duodenal and jejunal mucosa. YG supplementation down regulated the m-RNA expression of IL-12 gene (P < 0.05) and up regulated the m-RNA expression of Hsp-70 gene (P < 0.05) in the duodenal and ileal mucosa. 

In addition, YG supplementation down regulated the m-RNA expression of Hsp-70 (P < 0.05) and IFN-γ gene (P < 0.05) and up regulated the m-RNA expression of Hsp-90 gene (P < 0.05) in the jejunal mucosa. 

Moreover, YG supplementation increased the relative abundance of Lactobacillus (P < 0.05) in the genus level and decreased the content of acetate (P < 0.05). The researcher found that YG would be a potent alternative to prophylactic antibiotics in improving the gut health in weaned piglets. 

The study, published in Food and Function, was supported by the National Key Research and Development Program of China.