Colonic microbiota of weanling piglets fed diets containing rice distiller’s by-product

This study was conducted to evaluate the effects on gut microbiome of different levels of rice distiller’s by-product (RDP) in diets of weaned piglets. A total of 48 weaned castrated male crossbred pigs, initial body weight (IBW) 7.5±0.97 kg, and age about 4 wks, were used. They were randomly allocated into 3 diet groups of 4 blocks (4 pigs per block) according to similar IBW and sow origin by treatment. The piglets were fed either a control diet, a diet with 15% RDP, or a diet with 30% RDP for a total of 35 days experiment. On days 14 and 35, eight piglets per treatment (2 per block) were exsanguinated and eviscerated for collection of digesta samples at 6 hours after feeding. Individual samples of each colonic digesta were collected in sterile tubes (PSP@ Spin Stool DNA Plus Kit, Germany), and DNA extracted in Biotechnology laboratory and stored at −20°C. PCR-amplification of the V1-V3 hypervariable region of bacterial 16S rRNA and sequencing on a MiSeq sequencer using v3 reagents (ILLUMINA, USA) were performed. Gene amplicon profiling of 16S rRNA revealed that colonic microbiota composition of weaned pigs differed between treatment groups and over periods, especially at family and genus levels. On day 14, a decreased proportion of Lachnospiraceae_ge, Ruminococcaceae_ge, Ruminococcaceae_UCG-005, Bacteroidales_ge, and Prevotella_1, and an increased proportion of Prevotellaceae_ge, Prevotella_2, and Prevotella_9 were observed with inclusion of RDP, while opposite effect was found on day 35. Additionally, the proportion of genera Lachnospiraceae_ge, Ruminococcaceae_ge, Ruminococcaceae_UCG-005, and Bacteroidales_ge decreased over periods in control diet but increased largely in RDP30, which was considered as beneficial to host. In conclusion, RDP in a favourable way modulated gastrointestinal microbiota composition in piglets.