• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1379-1382
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• 2005

High prolificacy in Garole sheep is due to existence of FecB mutation in an autosomal gene, bone morphogenetic protein receptor. The mutation enhances ovulation rate and in turn litter size in Garole sheep. Garole sires were crossed with non-prolific Malpura ewes with the aim to introduce prolificacy into Garole${\times}$Malpura (G${\times}$M) crosses through FecB introgression programme. In the present study, the effect of carrying booroola allele on litter size and live body weight was analyzed. The average litter size at birth was found to be 1.87 and 1.48 in the Garole and the G${\times}$M crosses, respectively. At weaning, 6-month, 9-month and 12-month of age, body weights were not affected by the presence of booroola allele (p>0.05); however, a significant effect (p<0.05) was found on body weight at birth in G${\times}$M crosses. In Garole sheep, no significant effect of FecB was observed on live weights in any age group. The interaction between the genetic group and the FecB genotype was also found to be non-significant.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.737-742
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• 2004

Garole, a prolific small sized sheep breed of West Bengal, was introduced in the Mutton project of the Institute in 1997 to explore the possibility of incorporating fecundity gene(s) into monotocus Malpura sheep of Rajasthan. Results of reproduction and production traits in respect of Garole${\times}$Malpura (G${\times}$M) half-breds have been obtained. Of 35 lambing obtained so far from the ewes of Garole${\times}$Malpura, 45.71% were twin lambing, whereas, Malpura sheep produced mostly single lamb except 2.55% twin lambing on an average. Other reproduction traits in G${\times}$M ewes such as lambing rate, litter size at birth and weaning were considerably improved over Malpura ewes. Results revealed that the fecundity genes responsible for increasing ovulation rate and litter size have been incorporated in to the G${\times}$M genotype and it might prove a valuable germ plasm towards evolving a new prolific strain of sheep. Interestingly, survivability of G${\times}$M half-breds was almost at par with the local Malpura sheep in harsh climatic conditions of semi-arid tropics. The body weights at different ages of G${\times}$M half-breds were on little lower side compared to contemporary Malpura lambs. Average kilogram of lambs weaned/ewe lambed in Malpura and G${\times}$M genetic group was 11.86 and 11.07 kg respectively. In view of minimizing the differences in body weights and kg of lambs weaned/ewe lambed between the two genetic groups, G${\times}$M ewes has to be backcrossed with Malpura rams to raise the inheritance of latter up to 75% level. However, further research is needed to reach on certain conclusions regarding net returns from such crosses.