Genealogical analysis of the Gochu Asturcelta pig breed: Insights for conservation

Abstract

The Breeders Association of Gochu Asturcelta (ACGA) initiated a recovery programme with six founders (three boars and three sows) in 2002. Information provided by a total of 3156 records (515 litters, 109 boars, and 309 sows) with father and mother known included in the Gochu Asturcelta herdbook was analyzed. The aim of the analyses was to assess if the mating policy implemented by the breeders association ACGA has been successful in preserving the genetic background of the founders in the present population. Two reference populations were defined: 232 individuals born in 2013 and 2014 (PopO), and 18 individuals born in 2012 and 2013 and kept for reproduction (PopR). Mean inbreeding was very high (0.230 ± 0.078 for the whole pedigree) with mean individual increase in inbreeding (ΔFi) of 0.067 ± 0.021 for PopO and PopR. However, mean ΔFi tended to keep steady values (around 0.07) after 2009. The number of founders identified for PopO and PopR was 4 and 5, respectively. The ratio between the effective number of ancestors (fa) and effective number of founders (fe) was roughly 1 for both PopO and PopR. This suggests that the ACGA's mating policy has avoided an extreme bottleneck in the population. However, drift caused noticeable losses of genetic diversity: ratio between the founder genome equivalents (fg) and fe was around 0.6 for the two reference populations. The current results highlight the need of unbalancing further genetic contributions to the population towards descendants of a very poorly represented founder (Fema 1).