Parity : A Selection Criteria for Pre-Weaning Morphometric Traits of West African Dwarfsheep = أعداد الولادات : معايير الانتخاب للصفات الشكلية قبل الفطام في سلالة خراف الدورف الغرب إفريقي

Abstract

One hundred and seventy six lambs produced by 84 ewes in their first to seventh parity were used to determine the effect of the number of births of ewe on the pre-weaning morpho metric traits of West African dwarf lambs.Body weight (BW), body length (BL), heart girth (HG) and height at wither (HW), were taken at birth, 4, 8 and 12 weeks after birth. Pre-weaning morpho metric traits of the lambs were significantly (P<0.05) affected by the parity of the ewe. The heaviest birth weight was recorded for lambs produced by fifth-parity ewes while the lambs from first parity had the least value. The highest value of BW, BL, and HW (4.74 ± 0.07kg, 37.00 ± 1.18cm, 41.32 ± 0.23cm) and (6.47 ± 0.09 kg, 40.40 ± 0.81cm, 46.11 ± 0.54 cm) were recorded from ewes in their fifth parity at weeks 4 and 8; respectively. Lambs produced by sixth parity ewes had the highest value of HG (39.00 ± 0.32cm, 42.01 ± 0.16 cm, and 42.80 ±0.86 cm) at birth, and 4 and 8 weeks after birth; respectively.However, the effect of parity on the growth performance tended to disappear at week 12. Sexual dimorphism was observed on all the morpho metric traits at week 12 in favour of male lambs. Growth performance of the lambs increases with parity though the effect was less significant at weaning.