Genetic analysis of quantitative traits and selection of superior breeds in the fourth generation of Pinan hybrid cattle H1-H4
In order to improve the germplasm performance of Pinan hybrid cattle,a total of 14 030 cows,from the first generation(H1)to the fourth generation(H4),born between 2000 and 2020,were selected for breeding and cultivation.36 individual phenotypic traits such as weight,body size,and appearance score of the cows were observed;and the genetic relationships of the three generations of each cow were recorded.After sorting and verifying the obtained data,a selection index(CBI)was calculated,and normal distribution probability genetic parameter analysis and discriminant analysis screening were performed on the populations of different genders and classifications(core cattle herds and superior cattle herds).The result were as follows:28 seed bulls and cows with good comprehensive performance in all indicators were selected from the core cow and bull populations of the H3 generation,and 56 seed bulls and cows with good comprehensive performance in all indicators were selected from the core cow and bull populations of the H4 generation.There were 100 heads with a CBI index greater than 116.40.The phenotype value ofthe core bulls was higher than that of the core cows,but the heritability and genetic progress coefficient R of the core cows are greater than those of the core bulls.The heritability of the same type of the cattle population was higher than that of the previous generation,with the average heritability of the core cattle population ranging from 0.4 to 0.5.The selection response coefficient R of the excellent breeding cattle herds selected from the H3 and H4 core cattle herds was higher in the H4 generation than in the H3 generation.The results of this study was of important reference value and guiding significance for breed selection and breeding.An increase in the R value of the selection response indicated that the next generation of the selected excellent breed of cattle might have a significant improvement in multiple observed phenotypic trait indicators,compared with the current generation.The population normal distribution probability genetic pa-rameter analysis and discriminant analysis methods proposed in this study were of important theoretical and practical significance,and were worthy of reference and discussion.
万方数据
维普
