GENETIC-ASPECTS OF PUBERTY IN AWASSI EWES

Body weight at puberty (WP), age at puberty (AP), weaning weight (WW) and growth rate from weaning to puberty (GR) in Awassi ewe lambs were studied. Average age of Awassi ewe lambs at first estrus was 278.9 +/- 6.3 days, their average body weight was 30.0 +/- 0.2 kg and represent s 61% of adult body weight. Heritability estimates for AP and WP were 0.35 +/- 0.06 and 0.26 +/- 0.08, respectively, and indicate that impro vement through selection would be effective. Genetic and phenotypic co rrelations between (WP) and (AP) were -0.65 and -0.37, respectively. G enetic and phenotypic correlations between AP and each WW and GR indic ate that selection on the basis of WW or/and GR would also result in g enetic improvement for AP. The same results have also been shown with WP. Genetic progress in WP and AP could be 0.27 kg more and 6.03 d les s per generation through mass selection. The conclusion from this work is that genetic improvement, in addition to better feeding and manage ment, offers the opportunity to increase output from existing resource s through breeding from ewe lambs, extending production life of the ew e, and shortening the generation interval, thus accelerating genetic i mprovement.