22S rDNA-Seq:  feed
The total community DNA was extracted from feeds and intestine by use of a MoBio Power Soil DNA extraction kit. The V3V4 region of the 16S rRNA gene was amplified in triplicate using the barcoded 338F and 806R primer set. PCR products were quantified, purified and sequenced by Illumina Miseq platform for assessment of bacterial diversity and community structure.