FACTORS AFFECTING FEED-EFFICIENCY, FEED-INTAKE AND DAILY GAIN OF AWASSI LAMBS

Daily gain, feed efficiency and feed intake of Awassi lambs during the 0-40 and 41-80 days postweaning periods were studied. The overall mea ns for daily gairi, feed efficiency and feed intake were 160+/-7.7 and 145+/-7.0 g/day. 5.480+/-0.2 and 8.83+/-0.39 kg feed intake/kg live w eight gain, and 827+/-24 and 1053+/-28 g/day during period 1 (0-40) an d period 2 (41-80) respectively. Daily gain was affected only by the l ambing season (P<0.01) in both the periods, and by the dam weight (P<0 .001) during period 1. Feed efficiency was affected significantly (P<0 .01) by lambing season during periods 1 (P<0.05) and during period 2, and by type of birth (P<0.01) during period 1. Heritability estimates of feed efficiency, feed intake and daily gain during periods 1 and 2 were 0.33+/-0.1 and 0.28+/-0.09, 0.39+/-0.07 and 0.32+/-0.10, and 0.33 +/-0.09 and 0.25+/-0.09 respectively. Genetic and phenotypic correlati ons between feed efficiency and daily gain ranged from -0.39 to -0.45, and those between feed intake and daily gain from 0.32 to 0.40 in bot h the periods. Expected genetic progress in feed efficiency, feed inta ke and daily gain through individual selection would be 2.3 and 1.75, 2.12 and 1.64, and 2.89% and 2.5% during periods 1 and 2 respectively.