Estimation of Genetic Parameters for Live Weight in South African Holstein CattleReportar como inadecuado




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Cow live weight is of economic importance in dairy production; however, it is not included in the selection objective for South African dairy cattle. Variance components estimates are a prerequisite to incorporating a trait in the breeding objective. Variance components were estimated for live weight of lactating Holstein cows on two South African dairy herds. Live weight records on 9843 lactating cows, collected over a period of three years, were used. An analysis of variance was carried out to determine fixed effects to include in the model by the least squares method, using the Generalised Linear Models procedure of the Statistical Analysis System. Variance components were estimated by the Restricted Maximum Likelihood procedure using the ASREML programme. A high heritability estimate of 0.74 ± 0.19 is found, which suggests that there is scope for significant response to selection on live weight in the South African Holstein cattle population. A repeatability estimate of 0.86 was obtained. These results form the basis for incorporating live weight in the breeding objective for South African Holstein cattle. Further work, however, needs to be done to develop estimates based on a representative sample of the whole population, as the current study is based on data from only two herds.

KEYWORDS

Live Weight, Breeding Objective, Variance Components, Heritability, Dairy Cows

Cite this paper

Ramatsoma, N. , Banga, C. , Lehloenya, K. and Gibson, R. 2015 Estimation of Genetic Parameters for Live Weight in South African Holstein Cattle. Open Journal of Animal Sciences, 5, 242-248. doi: 10.4236-ojas.2015.53028.





Autor: Nokuthula Innocentia Ramatsoma1,2*, Cuthbert Baldwin Banga2, Khoboso Christina Lehloenya3, Rory Gibson1

Fuente: http://www.scirp.org/



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