title: Repeatability and heritability of response to superovulation in Holstein cows.
abstract: The objective of this study was to estimate the relative effects of genetic and phenotypic factors on the efficacy and efficiency of superovulation for Holstein-Friesian cows reared in Brazil. A database, established by the Associacao Brasileira de Criadores de Bovinos da Raca Holandesa, consisting of a total of 5387 superovulations of 2941 cows distributed over 473 herds and sired by 690 bulls was used for the analysis. The records were analyzed by MTDFREML (Multiple Trait Derivative-Free Restricted Maximum Likelihood), using a repeatability animal model. The fixed effects included in the model were contemporaneous group (veterinarian, herd, year and season of the superovulation); number of semen doses; cow age; and superovulation order. The estimated repeatability of the number of the transferable embryos was low (0.13), and the estimated heritability was 0.03. These results indicate that environmental factors play a critical role in the response of a cow to a superovulation treatment. There is little evidence that future responses to superovulation by individual females can be predicted by previous treatment(s) or that superovulation response is an heritable trait.
authors.affiliation: UNESP, Jaboticabal, SP, Brazil.
authors.forename: H
authors.initials: H
authors.lastname: Tonhati
authors.forename: R B
authors.initials: RB
authors.lastname: Lôbo
authors.forename: H N
authors.initials: HN
authors.lastname: Oliveira
mesh_terms: D000375:Aging; D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000502:physiology*; D004624:Embryo Transfer; D004777:Environment; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary; D015203:Reproducibility of Results; D012621:Seasons; D013480:Superovulation / Q000235:genetics*