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Genetic correlations of young bull reproductive traits and heifer puberty traits with female reproductive performance in two tropical beef genotypes in northern Australia

journal contribution
posted on 21.08.2018, 00:00 by DJ Johnston, Nicholas Corbet, SA Barwick, ML Wolcott, RG Holroyd
Genetic correlations of young bull and heifer puberty traits with measures of early and lifetime female reproductive performance were estimated in two tropical beef cattle genotypes. Heifer age at puberty was highly (rg=-0.71± 0.11) and moderately (rg = -0.40 ± 0.20) genetically correlated with pregnancy rate at first annual mating (mating 1) and lifetime annual calving rate, respectively in Brahman (BRAH). In Tropical Composite (TCOMP), heifer age at puberty was highly correlated with reproductive outcomes from the first re-breed (mating 2), mainly due to its association with lactation anoestrous interval (rg = 0.72±0.17). Scrotal circumference were correlated with heifer age at puberty (rg = -0.41±0.11 at 12 months in BRAH; -0.30 ± 0.13 at 6 months in TCOMP) but correlations were lower with later female reproduction traits. Bull insulin-like growth factor-I was correlated with heifer age at puberty (rg = -0.56 ± 0.11 in BRAH; -0.43 ± 0.11 in TCOMP) and blood luteinising hormone concentration was moderately correlated with lactation anoestrous interval (rg = 0.59 ± 0.23) in TCOMP. Semen quality traits, including mass activity, motility and percent normal sperm were genetically correlated with lactation anoestrus and female lifetime female reproductive traits in both genotypes, but the magnitudes of the relationships differed with bull age at measurement. Preputial eversion and sheath scores were genetically associated with lifetime calving and weaning rates in both genotypes. Several of the early-in-life male and female measures examined were moderately to highly genetically correlated with early and lifetime female reproduction traits and may be useful as indirect selection criteria for improving female reproduction in tropical breeds in northern Australia. Journal compilation © CSIRO 2014.

Funding

Category 2 - Other Public Sector Grants Category

History

Volume

54

Issue

1

Start Page

74

End Page

84

Number of Pages

11

eISSN

1836-5787

ISSN

1836-0939

Publisher

CSIRO Publishing

Peer Reviewed

Yes

Open Access

No

External Author Affiliations

Cooperative Research Centre for Beef Genetic Technologies; University of New England; CCSIRO Livestock Industries; Department of Agriculture, Fisheries and Forestry

Era Eligible

Yes

Journal

Animal Production Science

Exports

CQUniversity

Keywords

Exports