Differential dynamics of the Jersey ruminal microbiome and immune response in the heat stress environment

Abstract

Abstract The rumen microbiome and immune cell play important roles in metabolism and immune responses of dairy cows. Accumulation data suggesting that different species of dairy cow have differential heat stress resistance, however underlying mechanism by which non-host factors contribute heat stress responses. Thus, our study was designed to understand the changes of rumen microbiome and immune cell function to heat stress response in Holstein and Jersey cows. Respiration rate and rectal temperature were measured and rumen fluid and blood were collected for microbiome analysis and immune cell analysis under normal or heat-stressed environment from eight Holstein and Jersey cows. The rumen bacteria diversity and microbial gene enrichment was analyzed by using the Illumina HiSeq™ 4000 platform. The blood of dairy cows was collected for peripheral blood mononuclear cells (PBMCs) isolation and PBMCs were analyzed by RNA sequencing (Marcrogen, Korea) under the same environmental condition. Holstein had significantly higher respiration rate compared to that of Jersey in heat stress environment. We also find that gene transcription patterns associated with functional activities in PBMCs are differ between Holstein and Jersey. Distinct and more prominent changes of rumen bacteria taxa and functional gene abundance in Jersey cows may be associated with better adaption ability to heat stress. These data suggest that different species of dairy cows had different metabolic and immunological system to adapt heat stress responses.