Selection And Breeding For Nucleus Herd In Dairy Cow Using Animal Model BLUP

Data were collected from Baoding dairy farm, containing records of 1952 milk yield, fat percentage, and fat yield for Holsteins between 1989 and 2000, as well as records of type classification for 192 cow in herd. Genetic evaluation was made using least squares model and animal model BLUP. The individual inbreeding coefficients, the fixed effects, the animal additive genetic effects of milk yield, fat percentage, fat yield, and type classification were calculated. Animal were ranked according to their BLUP-EBVs of main economic traits and TPI to provide information for selection. The phenotypic and genetic trends of the traits by year of birth were analyzed.The results suggest that year, calving month, lactation number all affected production performance. Recently, production performance was in upward trend. Summer had the most negative effect on production. Milk yield increased continuously as lactation parity increased. The fifth lactation reached the peak production, since then decreased.The first three bulls arrayed by TPI were H761, 530, H61, purchased from Beijing , and Tianjin bull station. Their TPI was 1111.28, 1068.08, 864.92, respectively. The cow arrayed first three were 9695, 9848, 9731, 9847, 9628, 9831, 9857, 94126, 9837, 9855, and their TPI was 1207.65, 1112.72, 1110.48, 1101.68, 1091.48, 1086.20, 1053.29, 1024.58,931.35.70 dairy cows (TPI>450, and milk yield>7500Kg) were selected to set up nucleus herd. The means of milk yield, fat percentage, fat yield, type classification, and TPI were 1292.3, 0.0064, 10.97, 0.4757, 677.76, respectively. The number of cows were 32, 29, and 9 which milk yield was 7500~8000, 8001 ~ 9000, 9001~ 10000, respectively.