title: Heritability estimates for the duration of fertility in Alexandria and Fayoumi chickens.
abstract: Two Alexandria lines selected for high (HL) and low (LL) body weight and one unselected Fayoumi line were compared for the duration of fertility in both sexes. In the parents, LL had a significantly higher duration of fertility than HL and Fayoumi. In the female progeny, the mean duration of fertility in HL, LL, and Fayoumi were 9.76, 11.20, and 10.66 days, respectively, and the difference among them were highly significant. Based on the sire-plus-dam components of variance, the heritability estimates of the duration of fertility were determined. Heritability estimates obtained by regressed offspring mean on dam estimate were 0.44 in HL, 0.14 in LL, and 0.93 in the Fayoumi. It can be concluded that the genetic variance of this feature - duration of fertility - was relatively high.
mesh_terms: D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000235:genetics* / Q000502:physiology; D004534:Egypt; D005260:Female; D005298:Fertility; D008297:Male; D012737:Sex Factors; D013997:Time Factors