Evaluación de la consanguinidad por métodos clásicos y de descomposición ancestral en la raza Negra Andaluza

The Negra Andaluza cattle breed has improved its status, moving from “endangered” to “threatened” thanks to the significant efforts made by breeders, universities, and governments in developing the breeding program that has been ongoing since 2012. This program is based on maintaining genetic diversity and maternal reproductive efficiency. Genetic diversity studies have been conducted using genealogical information, revealing a higher contribution to inbreeding from the bulls, which could lead to a bottleneck. On the other hand, the negative impact of inbreeding depression on productive and reproductive traits is well known, with the latter being more significantly affected. In recent years, new methods have been developed to analyze inbreeding within populations, such as the “pedigree purging” methodologies, which divide inbreeding into ancestral and new components. Among these methods are those proposed by Ballou, Kalinowski, and the Ancestral History Coefficient (AHC). The aim of this research was to evaluate both classical and purging-based methods for estimating inbreeding in this breed. A database was used containing 8,555 animals born between January 1994 and May 2020, with sire and dam information. Pedigree completeness and inbreeding were estimated using classical and recursive methods, as well as the Ballou, Kalinowski, and AHC methods, employing the software ENDOG, CFC, RelaX2, and GRAIN. The results showed inbreeding values of 5.95% (classical), 9.45% (recursive), 1.98% (Ballou), 2.06% (AHC), and 0.79% (old Kalinowski) and 5.16% (new Kalinowski). Additionally, Ballou and AHC methods showed an increasing trend, while new inbreeding and classical inbreeding have tended to decrease since 2017. In conclusion, the Negra Andaluza breed is undergoing a process of increased inbreeding due to the introduction of new ancestors compared to older ones, which highlights the need to pay careful attention to future matings in order to reduce this trend.