In recent years, there has been an interest in improving the robustness, efficiency, and profitability of dairy cattle. In pasture-based seasonal calving systems, failure to become pregnant during the breeding season results in important economic losses as maximum profit is attained by minimizing costs and increasing the proportion of grass in the diet of the lactating dairy cow. For conventional dairy production systems, dairy producers primarily strive to maximize production but are becoming increasingly aware of the economic consequences of sub-optimal cow fertility and survival. By crossbreeding, the dairy producer’s objective is to exploit the favorable characteristics of ‘alternative’ breeds, remove the negative effects associated with inbreeding, and capitalize on a phenomenon known as heterosis.
Recent research results illustrate greater fertility and survival with crossbred cows compared with pure Holstein cows using a range of modern breeds, and within the context of both grass-based and high input confinement production environments. Research conducted in Ireland during the early 2000's concluded that of dairy breeds used for crossbreeding (Normande, Montbéliarde, and Norwegian Red), the Norwegian Red was most suited to seasonal grass-based production because of their advantage for fertility and survival.
A follow-up study confirmed a fertility advantage (higher proportion pregnant after the breeding season) with Norwegian Red×Holstein compared with Holstein. Studies conducted in Northern Ireland also found superior fertility performance with Jersey crossbred cows offered low and moderate concentrate diets. In New Zealand, crossbred dairy cattle (primarily Jersey×Holstein) are achieving similar rates of genetic gain for profitability compared to the purebred populations, but creating additional gain derived from economic heterosis.
In the United States, analysis of data from California showed higher first-service conception rates for Scandinavian Red×Holstein and Montbéliarde×Holstein compared with Holsteins. The crossbreds also had fewer days open and greater survival. At Penn State University, Brown Swiss×Holstein cows had 17 fewer days open than Holstein cows during first lactation. At the University of Minnesota, Jersey crossbred cows had higher first-service conception rates, fewer days open, and a higher percentage calving a third time compared with Holsteins. The literature clearly illustrates favorable animal performance benefits from crossbreeding, using a range of modern breeds, and within the context of both grass-based and high-input confinement production environments.