The Role of Reproduction and Genetic Variation in Polish White-Backed Cows in the Breed Restoration Process

SIMPLE SUMMARY: One of the few cattle breeds in the world undergoing restoration is the Polish White-Backed breed. The objective of this study was to use autosomal microsatellite markers to investigate genetic diversity in cows of this breed, taking into account their origin, and to evaluate their reproductive parameters. The findings of this work not only confirm the value of protecting local cattle breeds around the world, but may also be of importance in developing selection indices for highly productive breeds, in which reproductive functioning should be one of the most important factors considered. ABSTRACT: Local breeds are the main reservoir of biodiversity of farm animals. According to FAO, they account for 87% of all described breeds in the world. To ensure that they are adequately protected, they should be continually monitored for genetic variation. Another crucial factor is reproduction, which is the most important guarantee of population growth. In the present study, genetic variation in 372 Polish White-Backed cows was determined using DNA microsatellite sequences, taking into account their parentage. Reproductive parameters were analysed as well, based on data from 3658 lactations of 1128 Polish White-Backed cows. The results indicate that despite the small initial population and the implementation of a moderate selection of animals, the existing population of Polish White-Backed cattle has a high level of genetic variation, reflected in the degree of heterozygosity (0.761). Regarding reproductive traits, despite their late age at first calving, Polish White-Backed cows were shown to be distinguished by very good fertility parameters in comparison to other breeds raised in Poland. These findings not only confirm the value of protecting local cattle breeds around the world but may also be of importance in developing selection indices for highly productive breeds, in which reproductive functioning should be one of the most important factors considered.