title: Association between polymorphisms in somatotropic axis genes and fertility of Holstein dairy cows.
abstract: The aim of this study was to determine the effect of growth hormone receptor (GHR) AluI, insulin-like growth factor type 1 (IGF-I) SnaBI, and signal transducer and activator 5A (STAT5A) BstEII polymorphisms in the reproductive performance of Holstein dairy cows and the frequency of this genotypes in cows managed in different systems. This work studied 381 and 506 Holstein cows from semiextensive and intensive systems, respectively. The frequency of genotypes GHRAluI (+/-), IGF-ISnaBI (-/-) and (+/-), and STAT5ABstEII (-/-) was higher in animals from semiextensive system, whereas the frequency of the genotypes GHRAluI (+/+) and IGF-ISnaBI (+/+) was higher in animals from intensive system (P < 0.05). In the intensive system, cows from the STAT5ABstEII (-/-) genotype had a longer calving-first heat interval (P = 0.03). In conclusion, there was no association between the genotypes of GHRAluI and IGF-ISnaBI and fertility of Holstein cows raised in semiextensive or intensive regimes, although the genotype frequencies of the evaluated polymorphisms were different between the studied systems. The STAT5ABstEII polymorphism was associated with calving-first heat interval in Holstein cows raised in the intensive system, indicating that this gene could be a molecular marker for genetic selection to improve reproductive performance.
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Lucas Teixeira
authors.initials: LT
authors.lastname: Hax
authors.affiliation: Department of Nutrition, College of Nutrition, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Augusto
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Carolina Bespalhok
authors.initials: CB
authors.lastname: Jacometo
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Mattei
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Thaís Casarin
authors.initials: TC
authors.lastname: da Silva
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
authors.forename: Géssica
authors.initials: G
authors.lastname: Farina
authors.affiliation: Research Center, Education and Extension in Livestock (NUPEEC), College of Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil. Electronic address: marcio.nunescorrea@gmail.com.
authors.forename: Marcio Nunes
authors.initials: MN
authors.lastname: Corrêa
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000502:physiology; D005298:Fertility / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology; D005838:Genotype; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D011110:Polymorphism, Genetic; D011986:Receptors, Somatotropin / Q000235:genetics / Q000378:metabolism*; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000378:metabolism*
chemical_list: D011986:Receptors, Somatotropin; D050799:STAT5 Transcription Factor; D007334:Insulin-Like Growth Factor I
keywords: GHR; IGF-I; Reproduction; SNP; STAT5A