تأثير بعض العوامل غير الوراثية في أوزان العجول الشرابية المولودة تحت الظروف المحلية لمحافظة نينوى

The study was under taken to investigate the e ffect o f some non- genetic factors (sex of c alf, ye ar and season o f birth and parity of dam) on birth weight in Sharabi calves. Data from 137 Sharabi calves born in the Department o f Nineveh Agricultural Research - Rashidia Station, during the period from 2005-2011.Analysis of variance indicated that sex of calf, year and season of birth and parity of dam had significant effected (Pf0.05) on birth weight. The least square mean for birth weight of Sharabi calves was found to be 22.96 ± 0.798 kg. The effect of cal f sex on birth weight was highly significant (Pf0.05) , Male calves were 1.41 kg. heavier than females at birth. The spring born calves showed significantly highest birth weight (23.89kg.) than those born in winter season (21.84 kg.). Calves born in late parity dams ( fifth parity) were significantly higher weight than those in early parities. Low repeatability estimate (R= 0.28± 0.01) was reported for birth weight in this herd. This implies that more records will be required per cow to improve the herd’ s future per formance.