Characterization of best linear unbiased estimates generated from national genetic evaluations of reproductive performance, survival, and milk yield in dairy cows

摘要: Genetic evaluations decompose an observed phenotype into its genetic and nongenetic components; the former are termed BLUP with solutions for systematic environmental effects in statistical model best linear unbiased estimates (BLUE). Geneticists predominantly focus on rarely consider BLUE. The objective of this study, however, was to define quantify association between 8 herd-level characteristics BLUE 6 traits dairy herds, namely (1) age at first calving, (2) calving service interval (CFS), (3) number services, (4) (CIV), (5) survival, (6) milk yield. Phenotypic data along fixed random were generated from Irish national multi-breed cow fertility 3,445,557 cows; individual contemporary groups collapsed mean herd-year estimates. Data 5,707 spring-calving herds years 2007 2016 inclusive retained; analyses undertaken using mixed multiple regression models. Pearson coefficient correlations used relationships among trait BLUE, transition matrices understand dynamics herd over years. Based annual trends raw, BLUP, it estimated that associated least two-thirds improvement CIV production past 10 yr. Milk recording calved heifers time average 15 d younger, had almost 2 longer CFS but 2.3 shorter than non-milk-recording herds. Larger sizes worse both CIV. Expanding highest proportion cows born farm itself, average, younger By separating raw performance a selection their respective possible identify inferior management practices being compensated by superior genetics; similarly, identified because merit, not reaching full potential. This suggests could have pivotal role tailored decision support tool would enable producers most limiting factor hindering them achieving maximum performance.