عنوان مقاله [English]
This study was conducted to investigate the growth performance, body dimensions and fat-tail measurements of Chall male lambs reproduced from outbreeding of rams and ewe in Qazvin region. Two hundred 18 month ewe lamb were selected from a 1000-head flock and divided in two groups randomly. The first group (control) mated with rams from self-flock and the second group (treatment) mated with rams from other flock. After lambig, 10 male lambs from each group were selected randomly for recording the body dimensions and fat-tail measurements. The results showed that the average circumference of neck (36.6 V 35.1 cm), fat-tail circumference of upper part (40.4 V 37.1 cm) and fat-tail length of middle part (15.1 V 14 cm) in the treatment group was significantly higher than the control group. The effect of ram in control and treatment on birth weight (4.9 V 4.8 kg), weight at two, four, six and eight months (45.1 V 43.2 kg), final weight gain (40.2 V 38.4 kg) and body height and length, circumference of heart girth, loin width, diagonal length, and fat-tail measurements including length at the right, left and gap part, width at top, middle and down part, circumference at top, middle and down part, depth at top, middle and down part and fat-tail weight (2.4 V 2.3 kg) did not change significantly. In total, using rams from other flocks, increased circumference of neck and some fat-tail trait, but had no effect on growth performance of lambs.