Study of the genetic structure of the Holando Uruguayan breed using genetic markers

Intra-racial comparison

Abstract

A total of 354 blood samples were collected from Holstein Friesian cattle in Uruguay, distributed as follows: 138 cows, 42 bulls and 177 calves. Blood groups were determined by using 39 reagents from 8 systems (A, B, C, F, J, L, S, Z). In order to evaluate the degree of genetics variability in our sample, the average Heterozygosity was calculated. On the other hand, the average Heterozygosity was higher in cows than in calves, that together with a diminished nimber of alleles in B locus for progeny, points out a fall in genetic variability in the next generation. The significance of differences between the obtained and expected values of genotypic frequencies found in the progeny for systems J and Z seem to be caused by a limited number of sires rather than by other factors effecting the changes in gene frequencies. Nei's measures of normalized genetic identity and standard genetic distance between two populations were calculated for populations from Uruguay and USA over 7 loci. Those measures show that HF populations from the USA and Uruguay are the closest ones. Summing up all the results, we conclude that there is a decreaase in the genetic variability of the Uruguayan HF progeny generation and a high similarity between HF populations from the USA and Uruguay.