BLONDE-DAQUITAINE FOR COMMERCIAL CROSSBREEDING WITH GERMAN BROWN CATTLE

The aim of our investigation was to compare the sire breeds Blonde d'A quitaine (BA) and German Simmental (GS) for commercial crossbreeding w ith purebred German Brown (GB) in fertility and calving traits based o n field data. Fertility of the terminal sire, calving ease, calf survi val and effects of dystocia, stillbirth and twins on the consecutive f ertility, milk production and survival probability of the mother of ca lf were investigated. The analysis was based on milk recordings and AI -data from the years 1985 to 1990 of the German Brown cattle in Bavari a. About 485 000 and 650 000 observations, resp. in up to 5 200 herds were available for fertility and calving traits, resp. BA sires showed better paternal fertility than German Brown and German Simmental sire s, but dystocia occurred more frequently in BA crossbred calves. Morta lity of calves did not differ significantly in all three breeds. The i nfluence of calving problems on fertility, milk production and culling rate of the mother in the consecutive lactation did not show any sign ificant differences between sire breeds, but negative influence on fer tility and milk production traits is worse after birth of GS than afte r birth of BA crossbred calves. Culling rates were increased after vet erinary assisted calvings of GS crossbreds. In contrast stillbirth of BA crossbred calves extended culling of mothers.