Phylogenetic variation in raw cow milk microbiota

The microbiota of bulk tank raw milk is known to be closely related to that of microbial niches of the on-farm environment. Preserved forage types are part of this ecosystem and previous studies have shown variations in their microbial ecology. However, little is known of the microbiota of forage ration combinations and the transfer rates of associated species to milk. This study provides new insights into the microbial composition and structure of five forage rations fed to cows and associated raw milk from commercial dairy farms. Our results show that the mixture of grass/legume and corn silage significantly impacts the raw milk microbiota compared with a single forage-based ration.