Transferrin Genotypes and Their Relationship with Blood Constituents, Fertility and Cow Productivity

Abstract

The transferrin genotypes in a herd of Hereford cattle were determined. There were only two alleles present, Tf A and Tf D. The relationship between transferrin genotypes and levels of several blood constituents was studied in postweaning feeding periods along with calf performance using approximately 55 Hereford bull and heifer records over 2 years. All these measurements were recorded on weaned calves during a maintenance feeding period and a full feeding period to market weight and were collected by Johnson (1965). Of these measurements, only glutathione was significantly affected by different transferrin genotypes. Cow productivity and two measures of fertility were also studied using from 161 to 360 records over an 11-year period. Transferrin genotypes were not related with fertility measures nor was there an excess of heterozygous offspring born. Transferrin genotype differences were found for measures of cow productivity. Tf AA cows weaned lighter calves which had slower rates of gain and lower adjusted weights at 205 days than Tf AD or DD cows. There were no differences in birth weights related to transferrin genotypes. The agreement between these findings in beef cattle and those in dairy cattle milk production is discussed. Copyright © 1967. American Society of Animal Science . Copyright 1967 by American Society of Animal Science