Genome-wide association identifies methane production level relation to genetic control of digestive tract development in dairy cows

The global temperatures are increasing. This increase is partly due to methane (CH(4)) production from ruminants, including dairy cattle. Recent studies on dairy cattle have revealed the existence of a heritable variation in CH(4) production that enables mitigation strategies based on selective breeding. We have exploited the available heritable variation to study the genetic architecture of CH(4) production and detected genomic regions affecting CH(4) production. Although the detected regions explained only a small proportion of the heritable variance, we showed that potential QTL regions affecting CH(4) production were located within QTLs related to feed efficiency, milk-related traits, body size and health status. Five candidate genes were found: CYP51A1 on BTA 4, PPP1R16B on BTA 13, and NTHL1, TSC2, and PKD1 on BTA 25. These candidate genes were involved in a number of metabolic processes that are possibly related to CH(4) production. One of the most promising candidate genes (PKD1) was related to the development of the digestive tract. The results indicate that CH(4) production is a highly polygenic trait.