title: Mapping QTL influencing gastrointestinal nematode burden in Dutch Holstein-Friesian dairy cattle.
abstract: BACKGROUND
  Parasitic gastroenteritis caused by nematodes is only second to mastitis in terms of health costs to dairy farmers in developed countries. Sustainable control strategies complementing anthelmintics are desired, including selective breeding for enhanced resistance.
  
  
  CONCLUSIONS
  To quantify and characterize the genetic contribution to variation in resistance to gastro-intestinal parasites, we measured the heritability of faecal egg and larval counts in the Dutch Holstein-Friesian dairy cattle population. The heritability of faecal egg counts ranged from 7 to 21% and was generally higher than for larval counts. We performed a whole genome scan in 12 paternal half-daughter groups for a total of 768 cows, corresponding to the approximately 10% most and least infected daughters within each family (selective genotyping). Two genome-wide significant QTL were identified in an across-family analysis, respectively on chromosomes 9 and 19, coinciding with previous findings in orthologous chromosomal regions in sheep. We identified six more suggestive QTL by within-family analysis. An additional 73 informative SNPs were genotyped on chromosome 19 and the ensuing high density map used in a variance component approach to simultaneously exploit linkage and linkage disequilibrium in an initial inconclusive attempt to refine the QTL map position.
authors.affiliation: Unit of Animal Genomics, Faculty of Veterinary Medicine and Centre for Biomedical Integrative Genoproteomics, University of Liège (B43), Liège, Belgium. wouter.coppieters@ulg.ac.be
authors.forename: Wouter
authors.initials: W
authors.lastname: Coppieters
authors.forename: Ted H M
authors.initials: TH
authors.lastname: Mes
authors.forename: Tom
authors.initials: T
authors.lastname: Druet
authors.forename: Frédéric
authors.initials: F
authors.lastname: Farnir
authors.forename: Nico
authors.initials: N
authors.lastname: Tamma
authors.forename: Chris
authors.initials: C
authors.lastname: Schrooten
authors.forename: Albert W C A
authors.initials: AW
authors.lastname: Cornelissen
authors.forename: Michel
authors.initials: M
authors.lastname: Georges
authors.forename: Harm W
authors.initials: HW
authors.lastname: Ploeger
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000469:parasitology*; D002418:Cattle Diseases / Q000235:genetics / Q000469:parasitology; D002874:Chromosome Mapping / Q000662:veterinary*; D003612:Dairying; D005243:Feces / Q000469:parasitology; D005260:Female; D016678:Genome; D005838:Genotype; D007411:Intestinal Diseases, Parasitic / Q000235:genetics / Q000469:parasitology; D015810:Linkage Disequilibrium; D008297:Male; D009348:Nematoda / Q000502:physiology; D009349:Nematode Infections / Q000235:genetics / Q000469:parasitology; D010063:Ovum / Q000469:parasitology; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci