A note on the effect of live weight at mating on fertility of Awassi ewes in semi-arid north-west Syria

Abstract

Ninety Awassi ewes managed at different levels were used to study the effect of live weight mating on fertility over 3 years in semi-arid north-west Syria. During the 56-day pre-mating period fertile ewes had higher daily live-weight gains than infertile ewes ( P < 0·01), frequency of oestrous cycles increased as live weight increased ( P < 0·001) and fertile ewes tended to have more frequent oestruses than infertile ewes (P > 0·05). Ewe fertility was related (r = 0·87) to live weight at mating and twinning reached a maximum (four per 100 ewes lambing) in 51· to 56-kg ewes then decreased fP > 0·05). Maximum fertility can be expected in Awassi ewes weighing over 48 kg at mating in north-west Syria.