Genetic correlations in five body measurements, weight, type, and production of Holstein cows

Publisher Website
Google Scholar
Abstract
The data on 187 daughter-dam pairs were used to study phenotypic correlations, genetic correlations, and heritability of five body measurements, weight, type rating, milk production and butterfat production. This gave nine estimates of heritability and 36 estimates of genetic and 36 estimates of phenotypic correlations. The measurements, weight, and type were recorded at the animal's third birthday. The production records nearest to or including the third birthday were used to estimate production of both milk and butterfat;From the 36 phenotypic correlations between the nine variables, general, group, and special factors were derived. These factors include those genetic and environmental forces which cause phenotypic variations in the nine variables studied. The general factor had only a trace of an effect on milk production and butterfat production, and it accounted for only 4.1 percent of the variance in type rating. The general factor accounted for from 28.2 to 64.3 percent of the variance in the five body measurements and weight. The skeletal group factor accounted for 21.2, 16.0, 10.8, and 4.3 percent of the variance of wither height, chest depth, body length, and heart girth respectively, while the flesh-type group factor accounted for 7.8, 44.1, 39.4, and 1.7 percent of the variance in heart girth, paunch girth, weight, and type respectively. The special factors were of more importance to type, milk production, and fat production for they accounted for 94.2 percent of the variance of type and (100-trace) percent of the variation in both milk and fat production;The estimates of heritability ranged from 0.000 for type rating to .801 for chest depth. Paunch girth was the least heritable (.265) of any of the body measurements. Heritability of milk production and butterfat production was .254 and .350 respectively. The highest genetic correlation, .883, was between heart girth and weight. There was a genetic correlation of .707 between milk production and butterfat production, and the corresponding phenotypic correlation was .871. When type, milk production, or fat production was correlated with any of the other variables the resulting genetic correlation was zero. (Abstract shortened by UMI.)

This publication has 0 references indexed in Scilit: