title: Genetic analysis on accumulated productivity and calving intervals in Nelore cattle.
abstract: The aim of this study was to estimate genetic parameters for accumulated productivity (ACP), first calving interval (CI1), second calving interval (CI2), and mean calving interval (MCI) in Nelore beef cattle. The ACP trait is a reproduction index and comprises the total number of calves born per dam, weight of weaned calves, and age of the dam at calving. Genetic parameters were estimated by the average information restricted maximum likelihood method in two-trait analyses. The average heritability estimate for ACP was 0.17 (0.03). For CI1, CI2, and MCI, the heritability estimates were 0.02, 0.02, and 0.06, respectively. Genetic correlations between ACP with CI1, CI2, and MCI were -0.16 ± 0.47, -0.29 ± 0.53, and -0.40 ± 0.27, respectively. Despite of the low heritability estimates obtained in our study, reproduction traits should be further studied and their inclusion in the selection criteria must be evaluated in order to improve the performance of females because these traits are of great economic importance in beef cattle. Accumulated productivity could contribute to decrease the mean calving interval in Nelore cattle.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Centre for Genetic Improvement of Livestock (CGIL), N1G 2W1, Guelph, ON, Canada.
authors.forename: Daniela do Amaral
authors.initials: Ddo A
authors.lastname: Grossi
authors.affiliation: Departamento de Zootecnia, UNESP-Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 14884-900, Jaboticabal, SP, Brazil.
authors.forename: Mariana Piatto
authors.initials: MP
authors.lastname: Berton
authors.affiliation: Departamento de Ciências Exatas, UNESP-Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 14884-900, Jaboticabal, SP, Brazil.
authors.forename: Marcos Eli
authors.initials: ME
authors.lastname: Buzanskas
authors.affiliation: Departamento de Ciências Exatas, UNESP-Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 14884-900, Jaboticabal, SP, Brazil.
authors.forename: Tatiane Cristina Seleguim
authors.initials: TC
authors.lastname: Chud
authors.affiliation: Departamento de Ciências Exatas, UNESP-Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 14884-900, Jaboticabal, SP, Brazil.
authors.forename: Natália Vinhal
authors.initials: NV
authors.lastname: Grupioni
authors.affiliation: Instituto de Zootecnia, Centro APTA de Bovinos de Corte, 14174000, Sertãozinho, SP, Brazil.|Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900, Ribeirão Preto, SP, Brazil.
authors.forename: Claudia Cristina Paro
authors.initials: CC
authors.lastname: de Paz
authors.affiliation: Associação Nacional de Criadores e Pesquisadores, 14020-230, Ribeirão Preto, SP, Brazil.
authors.forename: Raysildo Barbosa
authors.initials: RB
authors.lastname: Lôbo
authors.affiliation: Departamento de Ciências Exatas, UNESP-Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 14884-900, Jaboticabal, SP, Brazil. danisio@fcav.unesp.br.
authors.forename: Danísio Prado
authors.initials: DP
authors.lastname: Munari
mesh_terms: D000818:Animals; D001938:Brazil; D002417:Cattle / Q000235:genetics / Q000502:physiology*; D005260:Female; D016013:Likelihood Functions; D008460:Meat; D010641:Phenotype; D012098:Reproduction / Q000235:genetics / Q000502:physiology*
keywords: Beef cattle; Genetic parameters; Heritability; Reproductive traits