Genetic parameters for production traits, resistance and resilience to Nematode parasites under different worm burden challenges in Corriedale sheep.

Characterized as the most important gastrointestinal parasite (GIP) in the world, Haemonchus contortus is also the most predominant and pathogenic genus in Uruguay, causing high morbidity and mortality rates in sheep flocks. For approximately 26 years resistance to GIP has been included in the National Genetic Evaluation (NGE) of Corriedale and Merino breeds, using Faecal Egg Count (FEC) as the selection criterion. The aim of the present study was to estimate genetic parameters for FEC, post-weaning Body Weight (BW), Packed Cell Volume (PCV), FAMACHA© and Body Condition Score (BCS), to determine the possibility to include these traits in the NGE of GIP resistance and resilience, as complementary selection criteria and to investigate the sensitivity of breeding values to different environmental worm burden challenges.

Genomic variation and population structure detected by single nucleotide polymorphism arrays in Corriedale, Merino and Creole sheep.

THE AIM OF THIS STUDY WAS TO INVESTIGATE THE GENETIC DIVERSITY WITHIN AND AMONG THREE BREEDS OF SHEEP: Corriedale, Merino and Creole. Sheep from the three breeds (Merino n = 110, Corriedale n = 108 and Creole n = 10) were genotyped using the Illumina Ovine SNP50 beadchip(®). Genetic diversity was evaluated by comparing the minor allele frequency (MAF) among breeds.