Improvement of fertility and calving ease of German Holsteins by crossing with North American Jerseys?

The Holstein cattle breed is dominating in milk production. Unfortunately, Holstein cattle also have disadvantages besides clear advantages in milk production, however, primarily in fitness traits. Due to the very low heritabilities of these traits only very restricted genetic progress by selection within a purebred population (e.g. Holstein) can be expected. The question which arises therefore is: Does a crossing of Holstein cows with Jerseys bulls offer a chance to increase the fertility of cows? Some results of a special crossing project with North American Jerseys are presented for the first time.