Evaluation of growth performance and inbreeding effect in Magra sheep

A study was conducted to evaluate the growth performance and effect of inbreeding on the growth performance in Magra sheep. The growth data generated on 5056 Magra sheep over a period of 22 years (1998 to 2019) at Arid Region Campus (ICAR-Central Sheep and Wool Research Institute), Bikaner (Rajasthan) were used in the study. The overall least squares means for body weights at birth, 3, 6, 9 and 12 months of age were 3.11±0.01, 16.09±0.06, 23.21±0.09, 27.98±0.10 and 30.22±0.12 kg respectively. The overall least squares means for average daily gain (ADG) during 0-3 (ADG1), 3-6 (ADG2) and 6-12 (ADG3) months of age were 143.95±0.70, 81.18±0.79 and 30.05±0.54 g, respectively. The results revealed 6.76, 19.71, 17.04, 25.65 and 30.59% improvement in body weights at birth, 3, 6, 9 and 12 months of age, respectively during the last 22 years. On all the growth traits, significant effects of year of birth, sex and dam's weight at lambing were observed. There was non-significant effect of inbreeding on 6MWT, 12MWT, ADG2 and ADG3. Inbreeding classes had variation; however negative effect was not seen. The study concluded that the mating programme of Magra sheep is in the right direction; however, regular monitoring of inbreeding in the flock may be followed and non-genetic factors affecting growth must be monitored so as to attain better growth rates in Magra sheep.