Weights and Body Measurements of Purebred Holstein and Guernsey Females and Their Crossbreds

Abstract

Body weights and five linear body measurements of purebred Holstein and Guernsey females and their crossbreds in generation 3 were analyzed and compared. The two crossbred groups in generation 3 were Holstein- Guernsey and Holstein-5/8 Guernsey. Weights and measurements were taken at 3, 6, 12, 18, 24, 30, 36, and 48 mo of age. Means of crossbreds exceeded means of purebreds in most cases at all ages for all variables even though in more than half the cases the differences between means were not significant. The percentage increase for weight ranged from 1.6 to 5.8%. Percentage increases were greater for weight than for body measurements. Mean squares associated with breed of sire, breed of dam, and purebred versus crossbred comparison were significant in 46, 43, and 18 out of the 48 cases. Nonadditive genetic effects from crossing Holsteins and Guernseys on linear body measurements and weights are small compared to the additive genetic differences between and within these two breeds.