Intestinal microbiota of commercial pigs at different growth stages
DNA was extracted from 250 mg of fecal samples and The V4 region of bacterial 16S rRNA gene was amplified from the total extracted DNA. PCR amplification was performed using the Takara Ex-taq polymerase and universal primers. The amplification program consisted of 1 cycle of 94 °C for 3 min; 40 cycles of 94 °C for 45 sec, 55 °C for 1 min, and 72 °C for 1.5 min; and finally 1 cycle of 72 °C for 10 min. DNA library was constructed using NEBNext Ultra DNA Library Prep Kit for Illumina.