Breeding and Genetics: Dairy Crossbreeding and Breeding Objectives

First-parity Holstein (H), Normande-Holstein (NxH) crossbred, Montbeliarde-Holstein (MxH) crossbred and Scandinavian-Holstein (SxH) crossbred cows calving from June 2001 to December 2003 were compared for dystocia and stillbirths from seven California herds. Dystocia scores ranging from 1 (no assistance) to 5 (hard pull) and stillbirths (1 for alive and 0 for dead) were recorded for 1695 Holstein cows, 205 Normande-Holstein cows, 157 Montbeliarde-Holstein cows and 110 Scandinavian-Holstein cows. Cows were bred to Brown Swiss, Holstein, Jersey, Normande, Montbeliarde and Scandinavian sires. Investigated were effects of calf sex, breed composition of cow, age at calving, breed of service sire, calving year and herd. For dystocia, sex of calf, calving year, breed of dam, breed of service sire and herd were significantly different (P<.05). The least squares mean for calf sex were 1.55 for males and 1.19 for females. Mean scores for dystocia for breed of dam were 1.59 (H), 1.44 (NxH), 1.26 (MxH) and 1.19 (SxH). Holstein sired calves (1.52) differed significantly (P<.05) from Jersey sires (1.11), and Holstein sires differed (P<.01) from Scandinavian sires (1.30). For stillbirths, sex of calf, calving year, breed of dam, breed of service sire and herd were significantly different (P<.01). Male calves (12%) had higher stillbirths than females (2%). Mean scores for stillbirths for breed of dam were 12% (H), 8% (NxH), 3% (MxH) and 5% (SxH). Holstein sires had the highest rate of stillbirths (12%), and rates for the other breeds of sires were 10% for Brown Swiss, 3% for Jersey, 7% for Montbeliarde, 4% for Normande, and 5% for Scandinavian sires. Holstein sires differed significantly from Jersey (P<.05) and Scandinavian sires (P<.01). Brown Swiss differed significantly from Scandinavian sires (P<.05).