title: Genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford beef cattle breeds in Kenya.
abstract: This study estimated genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and Hereford cattle in Kenya. Traits considered were birth weight (BW, kg), pre-weaning average daily gain (ADG, kg/day) and weaning weight (WW, kg); calving interval (CI, days) and age at first calving (AFC, days). Direct heritability estimates for growth traits were 0.36 and 0.21; 0.25 and 0.10; 0.23 and 0.13 for BW, ADG and WW in Charolais and Hereford, respectively. Maternal heritability estimates were 0.11 and 0.01; 0.18 and 0.00; 0.17 and 0.17 for BW, ADG and WW in Charolais and Hereford, respectively. Direct-maternal genetic correlations ranged between -0.46 and 1.00; -0.51 and -1.00; -0.47 and -0.39 for BW, ADG and WW in Charolais and Hereford, respectively. Genetic correlations ranged from -0.99 to unity and -1.00 to unity for growth and fertility traits respectively. Prospects for improvement of growth and fertility traits exist.
authors.affiliation: Department of Animal Sciences, Egerton University, Kenya.
authors.forename: J S K
authors.initials: JS
authors.lastname: Orenge
authors.forename: E D
authors.initials: ED
authors.lastname: Ilatsia
authors.forename: I S
authors.initials: IS
authors.lastname: Kosgey
authors.forename: A K
authors.initials: AK
authors.lastname: Kahi
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000235:genetics; D001835:Body Weight / Q000235:genetics; D002417:Cattle / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000235:genetics / Q000502:physiology*; D007630:Kenya; D008297:Male; D008957:Models, Genetic; D015233:Models, Statistical; D019655:Quantitative Trait, Heritable