Rumen microbiota and its relation to fermentation in lactose-fed calves

In our previous studies, we revealed the effect of lactose inclusion in calf starters on growth performance and gut development calves. We conducted present study as a follow-up to identify shift rumen microbiota its relation fermentation when calves are fed lactose-containing starter. Thirty Holstein bull were divided into 2 starter treatment groups: texturized (i.e., control; n = 15) or which starch was replaced with at 10% LAC10; dry matter basis. All their respective ad libitum from d 7, kleingrass hay 35. Rumen digesta collected 80 3 wk after weaning) used analyze products. There no apparent feeding α-diversity overall composition microbiota. Amplicon sequencing real-time PCR quantification 16S rRNA gene confirmed that abundance butyrate-producing bacteria Butyrivibrio group Megasphaera elsdenii) did not differ between control LAC10 groups. Conversely, relative Mitsuokella spp., produce lactate, succinate, acetate, significantly higher lactose, whereas lactate concentration These findings suggest production can be elevated by an increase spp. then converted butyrate, propionate, since proportion propionate lower lactose-fed addition, observed Coriobacteriaceae Pseudoramibacter-Eubacterium group. Both these bacterial taxa include acetate-producing bacteria, positive correlation acetate-to-propionate ratio observed. Therefore, Coriobacteriaceae, partially explains acetate study.