BRIEF COMMUNICATION Genetic analysis for growth traits of prolific Garole × Malpura (GM) sheep Gopal R. Gowane & Ashish Chopra & L. L. L. Prince & A. K. Mishra & A. L. Arora Accepted: 11 October 2010 / Published online: 21 October 2010 # Springer Science+Business Media B.V. 2010 Abstract The FecB gene of Garole sheep was introgressed into non-prolific Malpura sheep to evolve a new prolific sheep strain Garole × Malpura (GM), suitable for semi-arid conditions. The present study was conducted to evaluate the impact of breeding program on production profile of GM sheep and to estimate the genetic parameters for growth traits of GM sheep. Overall prolificacy increased signifi- cantly in the new strain as compared to the native Malpura sheep. In the GM flock of F2 and F2 onwards generation 35.31% single, 55.83% twins, 8.16% triplet and 0.70% quadruplets were obtained during lambing. Over the years, prolificacy in the flock has increased significantly. Over all least squares means for birth weight, 3, 6, 9, 12 month weight, pre-weaning gain (ADG1) and post-weaning gain (ADG2) were 1.82±0.03, 9.44±0.18, 14.00±0.24, 16.56± 0.33, and 19.32±0.35 kg, and 84.08±1.84 and 35.19± 0.99 g, respectively. Majority of the fixed effects had significant influence on the performance traits. The herita- bility estimates for birth, 3, 6, 9, 12 month weight, ADG1 and ADG2 were 0.30±0.11, 0.22±0.09, 0.23±0.10, 0.27± 0.10, 0.30±0.11, 0.17±0.08, and 0.17±0.10, respectively. Modest rate of genetic progress seems possible for these traits under selection. The genetic and phenotypic correla- tions among different body weights were moderate to high and positive. The genetic correlation of pre and post- weaning daily gains with body weight traits were also high and positive. Keywords Garole × Malpura sheep . Genetic parameters . Growth traits . Prolificacy Introduction Improving prolificacy of sheep flocks can increase the profitability of sheep production. Lamb production is the most important source of income for sheep rearer. Most of the sheep breeds of India produce single lamb except Garole, highly prolific breed of sheep (Mishra et al., 2005) and Kendrapara sheep (Kumar et al., 2009). Malpura is an indigenous mutton type sheep breed found in semiarid region of Rajasthan. Malpura sheep is reared by small holders who graze them on fallow lands, crop residue, and also take them on migration during the period of scarcity. A sizable flock of around 500 Malpura sheep is maintained at Central Sheep and Wool Research Institute, Avikanagar, India. These sheep have an average litter size of 1.04 and they attain average weight of 14.16±0.11 kg at weaning (3 months) and 21.44±0.11 kg at 6-month age (Mishra et al., 2009) at which farmers usually sell their animals. The FecB mutation has been identified in Indian Garole sheep and hypothesized that the gene is same as that reported in Australian Booroola Merino (Davis et al., 2002). Consid- ering the importance of prolific gene, a cross breeding scheme was initiated in the year 1996–1997 at Central Sheep and Wool Research Institute, Avikanagar, India to introgress FecB gene possessed by Garole of hot humid environment into the non-prolific and best adapted mutton type Malpura sheep of semi-arid tropical environment to G. R. Gowane (*) : A. Chopra : L. L. L. Prince : A. L. Arora Division of Animal Genetic and Breeding, Central Sheep and Wool Research Institute, Avikanagar 304501 Rajasthan, India e-mail: gopalgowane@gmail.com A. K. Mishra Central Avian Research Institute, Izatnagar, Bareilly 243122 Uttar Pradesh, India Trop Anim Health Prod (2011) 43:299–303 DOI 10.1007/s11250-010-9718-8