Agriculture & Food, Volume 10, 2022

Abstract: The Lusitano Horse (LH) is a Portuguese equine breed, with special economic relevance in the national and international scene and one of the most ancients in the world. A group of 2699 males of the LH breed, representatives of all possible paternal lineages of the breed, born over three decades (between 1985 and 2010) and registered as stallions in the Studbook, were genotyped with the current and the additional panel of microsatellite markers recommended for horse genotyping by the International Society for Animal Genetics. All loci were polymorphic and informative. The genetic diversity, quantified by the expected heterozygosity, was 70 %, which is above the average estimated for the genetic diversity for American and other European breeds. The mean allelic richness was 8.19 for the whole group and the mean inbreeding index value was 3.4 %, which is within the average values for other equine breeds. All loci but two showed deficit in heterozygotes and only four were in Hardy-Weinberg Equilibrium. Monitoring the genetic diversity of males along the years could contribute to informed decisions in the management of paternal lineages and for LH breeding and conservation strategies.