Turopolje Pig: Between Conservation and Sustainability

Abstract

The Turopolje pig is a fatty-type pig breed created during the Middle Ages in the Turopolje region in Central Croatia. Although the population of the Turopolje pig is stable today, this breed is still one of the endangered breeds that are severely threatened by inbreeding. The aim of this work was to evaluate the genetic diversity parameters of the recent Turopolje pig population in Croatia and to consider mating strategies to limit the increase in inbreeding in the population using algorithms within an optimal contribution selection frame. The pedigree of 1155 individuals was analysed. In addition to the basic pedigree structure, the following population parameters were analysed: average coefficient of inbreeding; mean rate of increase in coancestry; increase in coancestry between any individuals; effective population size. Based on obtained parameters, mating optimization using estimated kinship between candidates in several scenarios was carried out, restricting maximal kinship between candidates on a minimal possible value 0.07, as the least possible level of kinship, candidates on a value of 0.10, and candidates on a value of 0.25. The average inbreeding coefficient (F) in the population was 0.03, while the average F of inbred animals was 0.10. The effective population size obtained from pedigrees based on the increase in coancestry (0.17) was 29.14. Mating plans were created from 5 active boars and 120 sows in different scenarios with constraint on the level of kinship between candidates. The least possible level of kinship was 0.07, and no available solutions were under this level. With the increase in the allowed kinship between candidates, the level of inbreeding increased from 0.01 to 0.06 in the next generation. Under practical conditions, mating between ideal individuals in local pig populations is not always possible, and the use of optimisation algorithms allows alternative mating within existing populations to be considered. Finally, this approach opens up the possibility of potentially improving sustainable breeding through selection by considering breeding values for economically important traits. This approach can help to differentiate the Turopolje pig breed from other commercial and local breeds, e.g., for meat quality traits.