The association between microsatellite Bm6438 and milk performance traits in Polish Holstein-Friesian cattle

Abstract

The objective of this study was to verify the hypothesis postulating the location of QTL linked marker for milk performance traits in the proximal section of chromosome BTA1 by analyzing the microsatellite BM6438 alleles from heterozygous sires and the milk performance traits of the investigated cattle. The experiment covered 484 Polish Holstein-Friesian primiparous cows, the progeny of three unrelated sires, including 317 cows ‒ the progeny of two sires with 256/268 genotype and 167 cows – the progeny of a sire with 258/268 genotype. BM6438 polymorphism was determined by PCR and polyacrylamide gel electrophoresis. Three alleles (256, 258 and 268), forming 6 genotype groups, were identified among the studied cattle. In the progeny of sires with 256/268 genotype, statistically significant differences were found out in protein yield (the progeny of 2 sires) and in milk yield (the progeny of 1 sire). In both cases, the highest values of performance traits were recorded in 268/268 genotype groups, and the lowest in half-sib groups with 256/258 and 258/268 genotypes. The analysis covering the progeny of two sires with 256/268 genotype confirmed the regularities noted in individual families. 268/268 homozygotes had a highly significantly higher (P ≤ 0.01) protein yield than the remaining genotype groups. Statistically significant differences were also reported in the values of milk yield (P ≤ 0.05).