16S sequencing of rumen fluid from Holstein-Friesian cows with predisposition for higher and lower milk urea concentrations

The present study aims to elucidate contributing factors that distinguish between cows with predisposed higher (HMUg) and lower (LMUg) milk urea concentration in order to assess the value of routinely recorded milk urea concentrations as a substitutive trait for N-utilisation efficiency and N-excretion. The study focuses on differences in the diversity and composition of the rumen microbial community to increase knowledge of biological mechanisms contributing to the efficiency of nitrogen utilisation given the significant contribution of the rumen microbiota to the cow's nitrogen pools. Rumen fluid samples from 10 HMUg and 10 LMUg cows were analysed by 16S sequencing.