Breeding climate smart dairy cattle: from phenotyping to genetic selection for low methane emitting cattle

Summary

Several strategies have been proposed to reduce enteric methane emissions from dairy cattle, focusing on management, feeding strategies, feed additives, and animal breeding. Among these, animal breeding currently offers the most potential due to its permanent and cumulative effects, and the limited costs for farmers. To enable selective breeding, during this PhD project methane emissions were recorded from the cows' breath, using 'sniffers', during visits to milking robots on Dutch dairy farms. Data was collected from over one million milking sessions, involving more than 7,000 cows across 68 dairy farms, forming one of the largest experiments that record methane world-wide. The collected dataset was then used for genetic analyses, which aimed to investigate the applicability of sniffer sensors for measuring methane, the degree of heritability of methane emissions, and the genetic relationships between methane emissions and milk yield, body weight, and feed intake. The results are now being applied to set up practical breeding strategies to mitigate methane emissions, available to all dairy farmers in the Netherlands.