title: Detection of quantitative trait loci for maternal traits using high-density genotypes of Blonde d'Aquitaine beef cattle.
abstract: The genetic determinism of the calving and suckling performance of beef cows is little known whereas these maternal traits are of major economic importance in beef cattle production systems. This paper aims to identify QTL regions and candidate genes that affect maternal performance traits in the Blonde d'Aquitaine breed. Three calving performance traits were studied: the maternal effect on calving score from field data, the calving score and pelvic opening recorded in station for primiparous cows. Three other traits related to suckling performance were also analysed: the maternal effect on weaning weight from field data, milk yield and the udder swelling score recorded in station for primiparous cows. A total of 2,505 animals were genotyped from various chip densities and imputed in high density chips for 706,791 SNP. The number of genotyped animals with phenotypes ranged from 1,151 to 2,284, depending on the trait considered.
  
  
  
  QTL detections were performed using a Bayes C approach. Evidence for a QTL was based on Bayes Factor values. Putative candidate genes were proposed for the QTL with major evidence for one of the six traits and for the QTL shared by at least two of the three traits underlying either calving or suckling performance. Nine candidate genes were proposed for calving performance among the nine highlighted QTL regions. The neuroregulin gene on chromosome 27 was notably identified as a very likely candidate gene for maternal calving performance. As for suckling abilities, seven candidate genes were identified among the 15 highlighted QTL. In particular, the Group-Specific Component gene on chromosome 6, which encodes vitamin D binding protein, is likely to have a major effect on maternal weaning weight in the Blonde d'Aquitaine breed. This gene had already been linked to milk production and clinical mastitis in dairy cattle.
  
  
  
  In the near future, these QTL findings and the preliminary proposals of candidate genes which act on the maternal performance of beef cows should help to identify putative causal mutations based on sequence data from different cattle breeds.
authors.affiliation: UMR GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78352, France. alexis.michenet@jouy.inra.fr.|AURIVA, Les Nauzes, Soual, 81580, France. alexis.michenet@jouy.inra.fr.
authors.forename: Alexis
authors.initials: A
authors.lastname: Michenet
authors.affiliation: UMR GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78352, France.|ALLICE, 149 rue de Bercy, Paris, 75012, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Barbat
authors.affiliation: UMR GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78352, France.|ALLICE, 149 rue de Bercy, Paris, 75012, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Saintilan
authors.affiliation: UMR GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78352, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Venot
authors.affiliation: UMR GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78352, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Phocas
mesh_terms: D000818:Animals; D000833:Animals, Suckling / Q000235:genetics; D002417:Cattle; D005260:Female; D005838:Genotype; D009035:Mothers; D040641:Quantitative Trait Loci / Q000235:genetics*
keywords: Beef cattle; Calving performance; Milk yield; Quantitative trait locus (QTL); Suckling performance