Identification of the FecB mutation in Garole×Malpura sheep and its effect on litter size

High prolificacy in Garole sheep is due to the effect of the Booroola fecundity gene (FecB) mutation. In the present study, Garole rams were crossed with non-prolific Malpura ewes with the aim to increase prolificacy into Garole×Malpura (GM) crosses. The FecB genotyping was carried out by Forced-Restriction Fragment Length Polymorphism PCR technique in Garole (n = 64), GM crosses (n = 53) and Malpura sheep (n = 62). In 64 Garole samples genotyped, 55 were homozygous (FecBBB), 8 heterozygous (FecBB+) and 1 non-carrier (FecB++). The results showed that most Garole sheep (∼98.0%) carried the FecB allele. Out of 53 GM samples, 36 were heterozygous, 14 non-carriers and 3 were homozygous. Fifteen GM ewes genotyped that had at least one record of twins or triplets, revealed 1 homozygous and 14 heterozygous and 9 GM ewes that never produced twins were all non-carriers of the FecB mutation. The mean litter size was 1.95±0.08 and 1.60±0.11 in Garole and GM ewes, respectively. All Malpura sheep did not carry the FecB mutation. The results indicated that a single copy of mutated FecB gene resulted in 0.93 extra lambs in GM ewes. The introduction of the FecB gene from Garole to Malpura sheep improved litter sizes in GM crosses. © 2005 Elsevier B.V. All rights reserved