RELATIONSHIP OF BIRTH WEIGHT OF LAMBS WITH AGE OF EWES AT SERVICE IN RAMBOUILLET SHEEP

Data on birth weight of lambs and age of the dam at service in Rambouilet sheep maintained at the Livestock Experimental Station, Jaba, District Mansehra (NWFP), Pakistan were analyzed. The average age of the dam at service was 1337.57 ± 10.55 days. The least-square means for birth weight were 3.63 ± 0.11 and 3.41 ± 0.07 kg for single male and female lambs and 3.45 ± 0.12 and 3.29 ± 0.12 kg for male and female lambs born as twins. Age of the dam at service had a significant relationship with the birth weight of lambs. The correlation and regression coefficients between the above mentioned two traits were 0.37 and 0.025 ± 0.0001, respectively. Analysis of variance of age of the dam at service and birth weight of lambs due to regression revealed that this regression was statistically significant (P<0.01)