D
David Johnston
Researcher at University of New England (Australia)
Publications - 102
Citations - 3144
David Johnston is an academic researcher from University of New England (Australia). The author has contributed to research in topics: Beef cattle & Genetic correlation. The author has an hindex of 29, co-authored 102 publications receiving 2895 citations. Previous affiliations of David Johnston include Cooperative Research Centre.
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Journal ArticleDOI
Genetic and phenotypic variance and covariance components for feed intake, feed efficiency, and other postweaning traits in Angus cattle
TL;DR: Results indicate that genetic improvement in feed efficiency can be achieved through selection and, in general, correlated responses in growth and the other postweaning traits will be minimal.
Journal ArticleDOI
Genome-wide association studies of female reproduction in tropically adapted beef cattle.
R. J. Hawken,Yuandan Zhang,Marina R. S. Fortes,Marina R. S. Fortes,Marina R. S. Fortes,E. Collis,E. Collis,W. Barris,W. Barris,N. J. Corbet,N. J. Corbet,P J Williams,P J Williams,Geoffry Fordyce,Geoffry Fordyce,R. G. Holroyd,R. G. Holroyd,J. R. W. Walkley,J. R. W. Walkley,William Barendse,William Barendse,David Johnston,K. C. Prayaga,K. C. Prayaga,Bruce Tier,Antonio Reverter,Antonio Reverter,Sigrid A. Lehnert,Sigrid A. Lehnert +28 more
TL;DR: Very few of the significant markers for female reproduction traits for the Brahman and Tropical Composite breeds were located in the same chromosomal regions, however, fatness and BW traits as well as serum IGF1 concentration were found to be associated with similar genome regions within and between breeds.
Journal ArticleDOI
Genetic analyses of live-animal ultrasound and abattoir carcass traits in Australian Angus and Hereford cattle.
TL;DR: Genetic correlations between the same pair of carcass traits measured at yearling through scanning and directly at the abattoir were moderate to strongly positive, suggesting that selection using yearling ultrasound measurements of seedstock cattle should result in predictable genetic improvement forAbattoir carcass characteristics.
Journal ArticleDOI
Genetics of heifer puberty in two tropical beef genotypes in northern Australia and associations with heifer- and steer-production traits
David Johnston,Stephen Barwick,N. J. Corbet,N. J. Corbet,Geoffry Fordyce,R. G. Holroyd,Patrick James Williams,Patrick James Williams,Heather M Burrow +8 more
TL;DR: Results showed significant effects of location and birth month on the age at first CL and associated puberty traits, and selection can be used to change the heifer age at puberty in both genotypes.
Journal ArticleDOI
Days to calving in Angus cattle: Genetic and environmental effects, and covariances with other traits
David Johnston,Kim L Bunter +1 more
TL;DR: Field data from Angus herds in Australia were used to examine systematic effects influencing days to calving (DC) and to estimate genetic correlations between DC and other traits and covariances were obtained by Restricted Maximum Likelihood, using a derivative-free algorithm.