Temperamento de vacas cruzadas Holandês-Gir: Resposta ao treinamento para a primeira ordenha e estimativa de parâmetros genéticos
Carregando...
Data
2021-10-22
Autores
Taborda, Paula Alicia Batista
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo com a presente pesquisa foi contribuir com o conhecimento da variabilidade genética e fenotípica do temperamento na ordenha em gado leiteiro cruzado Holandês-Gir. A pesquisa foi realizada com o desenvolvimento de dois estudos. O estudo 1 teve como objetivo avaliar as diferenças individuais nas reações comportamentais de novilhas F1 Holandês-Gir submetidas a protocolos de habituação a humanos e aos procedimentos de ordenha. Em uma fazenda comercial 31 novilhas foram submetidas a um treinamento dividido em duas fases: habituação à proximidade humana (fase 1) e à sala de ordenha e ao contato físico com humanos (fase 2). Os resultados indicam que existe variação individual nas novilhas no treinamento para primeira ordenha. A maioria delas reduziu o medo em relação aos humanos e se habituou aos procedimentos de ordenha, então um treinamento prévio ordenha para diminuir reatividade. O estudo 2 teve como objetivo estimar parâmetros genéticos como herdabilidade, repetibilidade, correlações genéticas e fenotípicas para a reatividade na ordenha e produção de leite em vacas Holandês -Gir. A partir de 6.641 dados fenotípicos de reatividade na ordenha de 1.298 vacas cruzadas Holandês-Gir e dados genealógicos fornecidos pela Associação de Criadores de Girolando foram realizadas as estimativas dos componentes de (co) variância e parâmetros genéticos utilizando os programas da família BLUPF90 mediante inferência Bayesiana com THRGibbs1f90. Existe variação genética na variável reatividade na ordenha, o caráter é hereditário e tem alta repetibilidade. Existe uma grande importância em incluir a reatividade na ordenha como uma variável para seleção genética ao longo prazo.
The aim of this research was to contribute to the knowledge of the genetic and phenotypic variability of the milking temperament traits in Holstein-Gyr crossbred dairy cattle. Two studies were carried out. The aim of study 1 were evaluate individual differences in the behavioral reactions of F1 Holstein-Gyr heifers submitted habituation protocols to humans and to milking procedures. The study was carried out in a commercial farm with 31 heifers, which were underwent to a training protocol divided into two phases, addressing the cows’ habituation to human proximity (phase 1) and to the milking parlor and physical contact with humans (phase 2). The results showed individual variation in heifers’ reactions during training procedures for the first milking. Most of them have reduced fear of humans and become habituated to the milking parlor and physical contact. Thus, training leads decrease cows’ reactivity during first milking. The aim of study 2 were estimate genetic and phenotypic variability of milking reactivity and milk production traits in Holstein-Gyr cows. The study was carried out with 6,641 records of milking reactivity from 1,298 Holstein-Gyr crossbred cows. Genealogical data were provided by the Girolando Breeders Association. The estimates of (co)variance components and genetic parameters were performed using BLUPF90 family programs. It was observed genetic variation in the milking reactivity, which showed low heritability and high repeatability Milking reactivity must be considered in selective breeding programs of Girolando cattle.
The aim of this research was to contribute to the knowledge of the genetic and phenotypic variability of the milking temperament traits in Holstein-Gyr crossbred dairy cattle. Two studies were carried out. The aim of study 1 were evaluate individual differences in the behavioral reactions of F1 Holstein-Gyr heifers submitted habituation protocols to humans and to milking procedures. The study was carried out in a commercial farm with 31 heifers, which were underwent to a training protocol divided into two phases, addressing the cows’ habituation to human proximity (phase 1) and to the milking parlor and physical contact with humans (phase 2). The results showed individual variation in heifers’ reactions during training procedures for the first milking. Most of them have reduced fear of humans and become habituated to the milking parlor and physical contact. Thus, training leads decrease cows’ reactivity during first milking. The aim of study 2 were estimate genetic and phenotypic variability of milking reactivity and milk production traits in Holstein-Gyr cows. The study was carried out with 6,641 records of milking reactivity from 1,298 Holstein-Gyr crossbred cows. Genealogical data were provided by the Girolando Breeders Association. The estimates of (co)variance components and genetic parameters were performed using BLUPF90 family programs. It was observed genetic variation in the milking reactivity, which showed low heritability and high repeatability Milking reactivity must be considered in selective breeding programs of Girolando cattle.
Descrição
Palavras-chave
Bos taurus, Ordenha, Habituação a ordenha, Herdabilidade, Heatividade na ordenha, Habituation to milking, Genétically, Milking reactivity