Control of inbreeding in Banija spotted pig population using Optimisation methods

Abstract

The aim of the study was to estimate genetic diversity parameters for Banija spotted pig population and to apply optimisation methods to control the inbreeding in the population in three different scenarios. The first scenario consisted of minimizing inbreeding by minimizing the average kinship without considering breeding values. The second scenario was to minimize inbreeding by minimizing the average kinship accounting for breeding values. The third scenario was to apply traditional optimal contribution selection by maximizing the breeding value of the offspring. A total of 5 boars and 49 sows were selected to create mating plan minimise inbreeding in the next generation. The average inbreeding coefficient in the population was 6.97, while effective population size was 8.47. In the first scenario, different kinship constrains between candidates resulted in a change in the number of selected animals and a change in the average breeding values, such that the number of selected candidates increased when the constraint on kinship was stronger, with a simultaneous decrease in breeding values. The second scenario resulted in increased inbreeding when additional weight was placed on genetic gain. The Maximisation of breeding values resulted with drastically increased average inbreeding coefficient in the next generation. Due the small total and effective population size, the application of optimisation methods demonstrated that genetic improvement is possible at a high cost of loss of the genetic variability and preservation of diversity remains the first objective in the breeding programme for Banija spotted pig.

Keywords

• banija spotted pig
• inbreeding
• selection
• optimal contribution selection