Barrido genómico con el SNP-CHIP ovino 50k para la detección de QTL con influencia sobre la resistencia a nematodos intestinales en el ganado ovino de raza churraAnálisis de ligamiento para el recuento de huevos en heces

Zusammenfassung

Infections with gastrointestinal nematodes (GIN) remain one of the most prevalent parasitic diseases causing major economic losses in the sheep industries worldwide. In the last years, the increasing prevalence of resistance to anthelmintic has led to the search for alternative control methods such as selective breeding for increased GIN resistance. This study presents a linkage analysis for detection of QTL for faecal egg count (FEC), the traditional indicator trait commonly used to assess the level of GIN by the number of eggs per gram of faeces, in a commercial population of Spanish Churra sheep. The resource population included 596 adult ewes from 21 flocks and 15 half-sib families of the selection nucleus of the Churra sheep breeding programme. Faecal samples were collected from the studied animals for which genotypes for the Illumina OvineSNP50 BeadChip were already available. Chromosome-wise significant QTL were detected on chromosomes 4, 6, 8 and 25. The QTL identified on the first two of these chromosomes showed interesting coincidences with QTL previously reported in sheep for indicators of resistance to GIN. The results reported here suggest that the most significant QTL previously reported for FEC in Churra sheep by a microsatellite-based genome scan, on chromosome 6, is confirmed in the new analysed population.