Litter size records of Deccani crossbred sheep with 0, 1 or 2 copies of the FecB mutation were
analysed. FecB carrier ewes had higher live litter size per ewe lambed, at birth and at the age of 3
months than non-carrier ewes. Live litter size per ewe conceived, at birth and at 3 months age, of
both FecBB+ and FecBBB ewes was the same, weaning 50% more lambs per ewe conceived than noncarrier ewes. The dampened expression of the FecB mutation thus leads to less lamb losses and increased lamb production in the Deccan plateau production system.