Different beef breed sires used for crossbreeding with Swedish dairy cows - effects on calving performance and carcass traits

•Field data for different beef x dairy breed crosses and dairy breeds were analyzed.•Beef x dairy crossbreds were superior to dairy breeds for carcass traits.•The improvement of carcass traits by crossbreeding was largest in young bulls.•The use of late maturing beef breeds as sires gave more difficult calvings.•Stillbirth was less or equally frequent in crossbred compared to dairy calves. Improved potential for weight gain and carcass classification traits in calves aimed at slaughter from dairy herds would increase the calves’ economic value, and enable an increased beef production. At present, relatively low economic weights are placed on beef traits in the comprehensive Nordic dairy cattle breeding goal. An effective way to improve beef production from dairy herds is therefore to inseminate a larger proportion of dairy heifers and cows with beef bull semen. In the choice of beef bull breed, both effects on calving traits, carcass weight gain and carcass traits need to be considered. The aim of this study was therefore to compare different beef x dairy crosses regarding calving performance and carcass traits. Field data comprising in total close to 1.6 million calving records from Swedish herds, and more than 1.1 million carcass records from commercial slaughter houses, were analyzed using linear models. Differences in least-square means between different breed combinations were estimated for percentage of calving difficulty, stillbirth, daily carcass gain, carcass weight, EUROP conformation and fat classification. The dams were purebred Swedish Red (SR) or Swedish Holstein (SH), and the sires were either of purebred dairy (SR or SH) or of the beef breeds Angus, Hereford, Limousin, Simmental or Charolais. The results showed that crossbreeding dairy cows with beef bulls, especially of late maturing breeds, has potential to considerably improve beef production from dairy herds. Improvement of carcass characteristics and carcass gain were most noticeable in young crossbred bulls, where the highest increase for single breed combinations was 67% for conformation and 17% for carcass gain. Offspring of different beef x dairy combinations displayed varying average carcass gain and characteristics in terms of fatness and conformation in heifers, steers and young bulls, and would fit different types of production systems. Whereas crossbreeding had small or favorable effects on stillbirth, the use of late maturing beef breed sires negatively influenced the calving