Comparison of Body Weight and Dimensions at Birth and Weaning among Awassi and Chios Sheep Breeds and their Crosses

Data were on 333 and 187 birth and weaning, lambs born in the university of jordan agriculture research station at dear-alla, jordan, respectively. the objective was to compare body weight and dimensions at birth and weaning among awassi and chios breeds and their crosses. measurements taken were birth and weaning weights, heart girth, body length, wither, front leg, hip, and rear leg heights, shoulder and hip widths, tail length, width and circumference. singles were significantly (p< 0.001) weigh more than twins at birth (4.6 vs. 3.8 kg), weaning (19.4 vs. 17.4 kg) and (p<0.05) daily gain more (201 vs. 184 g). the effects of sex and dam breed on birth weight were also significant (p<0.01). birth type had significant (p<0.001) influence on all body dimensions at birth including heart girth, body length, wither, front leg, hip, and rear leg heights, shoulder and hip widths with singles having higher values than that for twins. dam breed significantly affected heart girth (p<0.001), shoulder and hip widths (p<0.01), with lambs of awassi dams having higher values than those of chios. males had significantly (p<0.05) higher values of heart girths in awassi sired lambs and lower values in those sired by chios. twin males had longer front leg than that of females, while single males and females had longer front leg than twins. tail length at birth was significantly (p<0.001) larger for lambs with chios sires or dams (15.4 or 15.9 cm, respectively) than those with awassi sires or dams (14.1 or 13.6 cm, respectively). the differences were also similarly different at weaning. average heterosis values of more than 5% were obtained from reciprocal crosses of awassi and chios sheep for body weight and growth to weaning. this may indicate a useful cross of awassi and chios for growth rates and weaning weight to be used by farmers in jordan