EFFECTS OF WEANING AGE AND SOME OTHER FACTORS ON GROWTH PERFORMANCE OF OSSIMI LAMBS

Abstract

ABSTRACTThis study was conducted to evaluate the effects of weaning age (early, traditional and lateweaning), parity number (first, second and third or more), birth type (single and twins) and sex of lamb(male and female) on growth performance of Ossimi lambs during post-weaning period. One hundredand five Ossimi lambs distributed into 3 groups based on their weaning age. Lambs of early weaninggroup weaned at 56 days age, while, the second and third groups of lambs were remained with theirmothers until 84 days (for traditional) and 112 days (for late weaning). The study performed at theexperimental farm belongs to Faculty of Agriculture at Moshtohor, Benha University, Egypt, andlasted 240 days. Monthly live body weight (LBW) was recorded individually, while average daily gain(ADG) and total weight gain (TWG) were calculated as growth indices. Both total and daily feedintake (TFI and DFI) of dry matter were determined, then feed conversion ratio (FCR) and economicalfeed efficiency (EFE) were calculated. Regarding the effect of weaning age, results indicated that earlyweaned lambs showed a significant (P<0.05) heavier LBW, while traditional and late weaned lambshad the lowest LBW from post-weaning until yearling weight. TWG and ADG of the early weanedlambs were greater than those weaned at the traditional and late ages (P<0.001). Obtained resultsindicated that parity number had a significant (P<0.05) effect on LBW, while it did not affected TWGand ADG of lambs. Concerning the effects of birth type and sex of lamb, results indicated that singleborn ram-lambs had heavier LBW and higher ADG than twin born ewe-lambs. TFI, DFI, FCR andEFE in early weaned lambs were greater (P˂0.001) than those weaned at the other ages. In conclusion,early weaning at 56 days of age, compared with weaning at 84 and 112 days, had positive effects onLBW, TWG and ADG of lambs. Thus, Ossimi sheep producers should wean their lambs at 56 days ofage to earn heavier LBW and higher TWG and ADG.