Genetic parameter estimates for body weight in local Venda chickens.
Genetic parameters were estimated for Venda chicken body weights at hatching, and at 4 weeks, 10 weeks and 21 weeks of age. A single-trait animal model with restricted maximum-likelihood procedures was used. Random effects were additive direct and maternal genetic, common environmental and error. The heritability estimates for direct effects were 0.36, 0.25, 0.41 and 0.22 for hatch, 4 weeks, 10 weeks and 21 weeks, respectively. The maternal effects were estimated at hatch and 4 weeks of age and were not present at later ages. Common environmental effects disappeared with increasing age. There was an antagonistic relationship between direct and maternal effects. The results show potential for genetic improvement of indigenous Venda chickens through selection. Maternal effects should be considered if selection is carried out at early ages.
Norris
D
D
Department of Animal Production, Turfloop Campus, University of Limpopo, Sovenga, South Africa. norrisd@ul.ac.za
Ngambi
J W
JW
D000367:Age Factors; D000818:Animals; D001835:Body Weight / Q000235:genetics*; D002645:Chickens / Q000235:genetics*; D004777:Environment; D005260:Female; D016013:Likelihood Functions; D008297:Male; D012641:Selection, Genetic