We identified six more suggestive QTL by within-family analysis. 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 performed a whole genome scan in 12 paternal half-daughter groups for a total of 768 cows, corresponding to the ~10% most and least infected daughters within each family (selective genotyping). The heritability of faecal egg counts ranged from 7 to 21% and was generally higher than for larval counts. Results and Conclusion 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. Sustainable control strategies complementing anthelmintics are desired, including selective breeding for enhanced resistance. Mapping QTL influencing gastrointestinal nematode burden in Dutch Holstein-Friesian dairy cattleĬoppieters, Wouter Mes, Ted HM Druet, Tom Farnir, Frédéric Tamma, Nico Schrooten, Chris Cornelissen, Albert WCA Georges, Michel Ploeger, Harm Wīackground Parasitic gastroenteritis caused by nematodes is only second to mastitis in terms of health costs to dairy farmers in developed countries. The results illustrate the power of restriction fragment length polymorphism methodology in visualizing genetic variability in dairy cattle populations. The chymosin locus was monomorphic with the restriction enzymes utilized. A low level of polymorphism was also observed at one of the beta-actin gene family loci. The population proved to be polymorphic at the growth hormone locus, with evidence consistent with the phenotypes being inherited in allelic fashion.
Israeli Holstein-Friesian dairy bulls were screened for restriction fragment length polymorphisms by hybridizing cloned DNA probes for bovine growth hormone, for chymosin, and for rat muscle beta-actin to restriction endonuclease-digested DNA immobilized on nitrocellulose filters. Restriction fragment length polymorphism among Israeli Holstein-Friesian dairy bulls.īeckmann, J S Kashi, Y Hallerman, E M Nave, A Soller, M