Title
Genetic parameters of milk production and reproduction traits of Girolando cattle in Brazil
Date Issued
02 January 2018
Access level
open access
Resource Type
journal article
Author(s)
Publisher(s)
Taylor and Francis Ltd.
Abstract
The objective of this study was to estimate the heritability and genetic, phenotypic, and environmental correlations between 305-day milk yield (305MY), age at first calving (AFC), calving interval (CI) and dry period length (DPL), as well as to compare the productive and reproductive performances of several groups of Girolando cows during their first, second and third parturitions in Brazil. Genetic parameters were estimated using uni- and bi-trait analyses via restricted maximum likelihood (REML). Heritability estimates were similar between uni- and bi-trait analyses and varied from 0.20 to 0.28, 0.00 to 0.08 and 0.07 to 0.14 for 305MY, CI and DPL, respectively, whereas AFC was 0.20. Genetic correlations between 305MY and AFC (–0.49) or DPL (–0.40 to –0.79) show a favourable association. However, an unfavourable genetic association was verified between 305MY and CI (0.59) in the first calving. Environmental and phenotypic correlations between 305MY and CI or DPL showed a favourable association (–0.25 to –0.42 and –0.14 to –0.44). Concerning the cow breed group, a decrease in 305MY was observed as the fraction of the Gyr breed increased, whereas animals from the 1/2 Holstein +1/2 Gyr crossbreeding group yielded better performances for AFC and CI. These results reveal large genetic, phenotypic and environmental variations that could be used in selection programmes.
Start page
22
End page
30
Volume
17
Issue
1
Language
English
OCDE Knowledge area
Ciencia animal, Ciencia de productos lácteos
Tecnología de modificación genética
Genética, Herencia
Subjects
Scopus EID
2-s2.0-85042379055
Source
Italian Journal of Animal Science
ISSN of the container
15944077
Sources of information:
Directorio de Producción Científica
Scopus