Genetic and nongenetic variation of multiple births in Austrian dual-purpose cows.

In recent decades, a general increase in multiple birth (MB) rate has been reported in both dairy and dual-purpose cattle breeds. As there is evidence that MB has negative effects on economically important traits in dairy cows, the aims of this study were to (i) investigate environmental and genetic factors affecting MB rate and (ii) assess the impact of MB on productive and nonproductive traits of the Austrian dual-purpose breeds Pinzgauer and Tyrol Grey. The dataset included 99,141 calvings of 33,791 Pinzgauer and 68,454 calvings of 19,244 Tyrol Grey cows recorded from 2000 to 2022.