Potential use of ground brown rice for weanling pigs.

The current study was to assess the effects of substituting corn with ground brown rice (GBR) on growth performance, immune status, and gut microbiota in weanling pigs. Seventy-two weanling pigs [28-day-old with 6.78 ± 0.94 kg body weight (BW)] were randomly allotted to 2 dietary treatments with 6 pens and 6 pigs (3 barrows and gilts) per pen with in a randomized complete block design. The control pigs were fed a typical diet for weanling pigs based on corn and soybean meal diet (control diet: CON), and the other pigs were fed a diet formulated by replacing corn with GBR for 35 days. Growth performance, immune status, and gut microbiota of weanling pigs were measured. The substitution of corn with GBR did not affect growth performance or diarrhea frequency. Additionally, there were no differences in white blood cell number, hematocrit, cortisol, C-reactive protein, serum TNF-α levels between pigs fed CON or GBR for the first 2 weeks after weaning. However, weanling pigs fed GBR had lower (P < 0.05) serum TGF-β1 level than those fed CON. Furthermore, weanling pigs fed GBR had increased (P < 0.05) relative abundance of phylum Firmicutes and genus Lactobacillus and Streptococcus and decreased (P < 0.05) relative abundance of phylum Bacteroidetes and genus Clostridium and Prevotella in the gut microbiota compared with those fed CON. In conclusion, there was no significant difference in growth performance when corn was replaced with GBR in diets for weanling pigs. Furthermore, the substitution of corn with GBR in weaning diet modulated immune status and gut microbiota of pigs by increasing beneficial microbial communities and reducing harmful microbial communities. Overall, GBR-based diet is a potentially alternative to corn-based diet without negative effects on growth performance, immune status and gut microbiota changes of weanling pigs.