title: Effect of polymorphisms at the STAT5A and FGF2 gene loci on reproduction, milk yield and lameness of Holstein cows.
abstract: The objective of this study was to investigate the association of polymorphisms at the STAT5A and FGF2 gene loci with fertility, lactation milk yield and lameness in dairy cattle. Five hundred and eighteen primiparous Holstein cows were included in the study. Several reproductive traits were considered including conception rate (0/1) at first insemination, conception rate (0/1) in a 305-day lactation, number of inseminations per conception, interval (days) from calving to conception for cows that conceived in the first 305 days of lactation and age at first calving. Milk yield and lameness incidence were also recorded. Genotyping was performed using PCR-RFLP. The effect of allele substitution at each gene locus on reproductive traits, milk yield and lameness was assessed with single-trait mixed linear models. No significant associations were found between reproduction traits and any of the studied polymorphisms, apart from age at first calving, for which STAT5A polymorphism had a suggestive effect (P = 0.077). In addition, no significant effect of any polymorphism on lameness was found. Replacement of the C by G allele at the STAT5A locus was associated with a significant (P<0.05) increase in lactation milk yield, suggesting that this locus could be considered in gene assisted selection for the genetic improvement of milk production.
authors.affiliation: Department of Animal Production, Aristotle University of Thessaloniki, PO Box 393, GR-54124 Thessaloniki, Greece. goikon@vet.auth.gr
authors.forename: G
authors.initials: G
authors.lastname: Oikonomou
authors.forename: G
authors.initials: G
authors.lastname: Michailidis
authors.forename: A
authors.initials: A
authors.lastname: Kougioumtzis
authors.forename: M
authors.initials: M
authors.lastname: Avdi
authors.forename: G
authors.initials: G
authors.lastname: Banos
mesh_terms: D017677:Age Distribution; D000818:Animals; D002417:Cattle / Q000235:genetics / Q000502:physiology; D002418:Cattle Diseases / Q000235:genetics*; D005260:Female; D005298:Fertility; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D006115:Greece; D007774:Lactation; D007794:Lameness, Animal; D016014:Linear Models; D008892:Milk / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D012098:Reproduction; D050799:STAT5 Transcription Factor / Q000235:genetics*
chemical_list: D050799:STAT5 Transcription Factor; D016222:Fibroblast Growth Factor 2