Genetic and Environmental Correlations Among Female Fertility Traits,and Between the Ability to Show Oestrus and Milk Production in Dairy Cattle |
| |
| Authors: | Anki Roxström Erling Strandberg Britt Berglund Ulf Emanuelson Jan Philipsson |
| |
| Institution: | 1. Department of Animal Health and Bioscience, Faculty of Agricultural Sciences , University of Aarhus , 8830, Tjele, Denmark Elke.Burow@agrsci.dk;3. Department of Animal Health and Bioscience, Faculty of Agricultural Sciences , University of Aarhus , 8830, Tjele, Denmark;4. Department of Genetics and Biotechnology, Faculty of Agricultural Sciences , University of Aarhus , 8830, Tjele, Denmark;5. Department of Farm Animal Behaviour and Husbandry, Faculty of Organic Agricultural Sciences , University of Kassel , 37213, Witzenhausen, Germany |
| |
| Abstract: | Genetic and environmental correlations were estimated both between the ability to show oestrus and milk production, and among different fertility traits (heat-intensity score, number of days between consecutive inseminations, number of inseminations per service period, interval between calving and first or last insemination, and interval between first and last insemination). Milk production was measured as the average of the energy-corrected milk yield on second and third monthly test days. The number of records were approximately 450000, 350000, 180000 and 75000 in the heifer period, first, second and third lactations, respectively. A linear, trivariate model that included the effects of herd-year, year, month, age and cow's sire was applied. The results indicated that further selection for increased milk production is not expected to deteriorate heat intensity. The number of days between calving and first insemination, the number of inseminations and the heat intensity were complementary, and can be recommended for a selection index for fertility. |
| |
| Keywords: | Dairy Cows Genetic Parameters Heat Intensity Heifer Period Milk Yield Reproduction |
|
|
