Evaluation of Growth Performance of Local and Dorper × Local Crossbred Sheep in Eastern Amhara Region, Ethiopia

The present study was performed to evaluate the on-station growth performance of local and Dorper × local crossbred sheep in eastern Amhara region, Ethiopia. Data on 302 lambs collected over a 4-year period (2009 to 2012) on local and Dorper × local crossbred sheep at Sirinka breeding, evaluation and distribution site were used in this study. Fixed effects considered were breed, lamb sex, birth season, birth type and birth year. Results revealed that breed was a significant source of variation that crossbred lambs consistently weighed more than the local sheep lambs at all ages. The mean birth weights of local and crossbred lambs were 2.36 ± 0.05 and 3.24 ± 0.04 kg, respectively. Sex was an important source of variation at weaning, six months and yearling of ages in which male lambs were superior over their female contemporaries. Lambs born in dry season were heavier than lambs born in wet season at six months (20.51±0.34 kg vs. 16.74±0.59 kg) and at yearling (31.12±0.38 kg vs. 27.72±0.82 kg). Single-born lambs were heavier (P<0.0001) than their multiple-born contemporaries. There was also significant (P<0.0001) difference on average daily gain of lambs between the crossbred (129.97±2.23 g/day) and local sheep (67.78±1.60 g/day) lambs from birth to weaning age. Males had higher pre-weaning average daily gain than females (125.83±3.38 vs. 116.93±3.13 g/day, P<0.05). Single-born lambs grew faster than their multiple contemporaries between birth to 30 days (179.85±3.15 vs. 127.27±6.82 g/day, P<0.0001) and birth to weaning (123.96±2.55 vs. 107.49±5.04 g/day, P<0.0001) of age. The crossbred lambs also gained higher (64.69±1.74 g/day) than the local sheep lambs (37.94±1.19 g/day) after weaning. Breed was found to have significant (P<0.0001) effect on overall growth rate, where crossbred lambs had higher growth rate than the local sheep lambs. There were generally crossbred lambs had better growth performance and higher growth rates than the local sheep lambs.