Non-genetic factors affecting lifetime body weights in Malpura Ram lambs

A study was conducted to evaluate the effect of non-genetic factors on lifetime (birth to 60 months of age) body weights in Malpura ram lambs. The data pertaining to 4134 ram lambs born from 2529 dams and 525 sires spread over a period of 45 years (1975 to 2019) maintained at ICAR-Central Sheep and Wool Research Institute, Avikanagar were used. The least squares means for body weights at birth (BWT), 3 (3WT), 6 (6WT), 9 (9WT), 12 (12WT), 18 (18WT), 24 (24WT), 30 (30WT), 36 (36WT), 42 (42WT), 48 (48WT), 54 (54WT) and 60 (60WT) months were 3.13±0.13, 15.10±0.08, 23.81±0.13, 27.46±0.19, 30.99±0.22, 34.76± 0.22, 38.86±0.29, 41.68±0.41, 44.18±0.56, 43.16±0.76, 44.05±0.96, 43.96±1.53 and 44.27±1.50 kg respectively. The effect of period of birth on all the body weights, season on birth, 3WT, 6WT, 9WT, 18WT, 24WT, 30WT, 36WT and 60WT and parity of dam on BWT, 3WT, 6WT, 9WT and 12WT was significant (P<0.01). Regression of ewe weights was significant (P<0.01) on all the body weights except 60WT (P<0.05). The results of the study showed that non-genetic factors play important role in the expression of lifetime body weights in Malpura ram lambs under semi-arid region of Rajasthan.