title: Fertility and survival of pure Holsteins versus crossbreds of Holstein with Normande, Montbeliarde, and Scandinavian Red.
abstract: First-calf pure Holsteins and Normande/Holstein, Montbeliarde/Holstein, and Scandinavian Red/Holstein crossbreds were compared for days to first breeding, first-service conception rate, days open, and survival. First-calf heifers were in 7 commercial dairies in California and calved from June 2002 to October 2004. Holsteins were required to have a recorded sire with a National Association of American Breeders code to assure they were sired by artificially inseminated bulls. Normande-, Montbeliarde-, and Scandinavian Red-sired crossbreds were all daughters of artificially inseminated bulls via imported semen. For days open, first-calf heifers were required to be at least 250 d in milk and those with greater than 250 d open were truncated to 250 d. Least squares means for days to first breeding were 69 d for Holsteins, 62 d for Normande/Holstein, 65 d for Montbeliarde/Holstein, and 66 d for Scandinavian Red/Holstein crossbreds, and differed significantly from pure Holsteins for Normande/Holstein and Montbeliarde/Holstein crossbreds. First-service conception rates were 22% for Holsteins, 35% for Normande/Holstein, 31% for Montbeliarde/Holstein, and 30% for Scandinavian Red/Holstein crossbreds and, again, differences from Holstein were significant for the Normande/Holstein and Montbeliarde/Holstein crossbreds. Least squares means for days open were 150 +/- 4.1 d for pure Holsteins, 123 +/- 3.8 d for Normande/Holstein, 131 +/- 4.4 d for Montbeliarde/Holstein, and 129 +/- 4.6 d for Scandinavian Red/Holstein crossbreds, and all 3 cross-bred groups had significantly fewer days open than pure Holsteins. Three measures of survival were to 30, 150, and 305 d postpartum, and all crossbred groups survived significantly longer than pure Holsteins during first lactation for all 3 measures of survival. Least squares means for survival to 30 d postpartum were significantly different for pure Holsteins (95%) vs. all crossbred groups (98%), were significantly different for survival to 150 d postpartum for pure Holsteins (91%) vs. all crossbred groups (96%), and were significantly different for survival to 305 d postpartum for pure Holsteins (86%) vs. all crossbred groups (92 or 93%).
authors.affiliation: Department of Animal Science, University of Minnesota, St. Paul, MN 55108, USA. hein0106@umn.edu
authors.forename: B J
authors.initials: BJ
authors.lastname: Heins
authors.forename: L B
authors.initials: LB
authors.lastname: Hansen
authors.forename: A J
authors.initials: AJ
authors.lastname: Seykora
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D003433:Crosses, Genetic; D003612:Dairying; D005260:Female; D005298:Fertility / Q000502:physiology*; D006824:Hybridization, Genetic / Q000502:physiology*; D007774:Lactation / Q000502:physiology*; D016018:Least-Squares Analysis; D008297:Male; D016017:Odds Ratio; D016019:Survival Analysis