Genetic and genomic solutions to improve feed efficiency and reduce environmental impact of dairy cattle

Traits related to resource use efficiency are dry matter intake (DMI), residual feed intake (RFI) and methane (CH4) emission. In an experimental dataset of 588 heifers, we showed that it is possible to decrease CH4 emission (predicted from DMI and ration composition) by selecting more efficient cows. Resource use efficiency phenotypes are difficult and expensive to measure, but genomic selection is a promising tool to enable selection for resource efficient cows. Using genomic selection, a reduction in predicted CH4 (g/d) of 15% in 10 years is theoretically possible. For DMI, an international collaboration between 9 countries in Europe, US and Australiasia has been established to assemble DMI data on >6,000 cows with phenotypes and genotypes. With all these developments, genetic selection is likely to make a major contribution to improving resource use efficiency, as long as feeding and management are adapted accordingly