Use of the FecB (Booroola) gene in sheep-breeding programs

Abstract

This workshop has its origins in two successful Australian Centre for International Agricultural Research (ACIAR) projects on meat sheep development in Maharashtra, India, that ran between 1998 and 2008. These projects aimed to increase sheep meat production by traditional smallholder sheep owners in an environment where the coarse wool produced by local sheep had lost most or all of its value. Smallholders are a socially and economically disadvantaged group in rural India and boosting their income and status was an important goal. The Indian partners on these projects had established that the low reproductive rate of sheep on the Deccan Plateau was a major limitation on productivity for meat production. They had identified the highly fecund Garole sheep from West Bengal, which regularly produce twins and some triplets, as a potential means of genetically improving the reproductive component of productivity. Under the ACIAR projects, it was established that the basis of fecundity in the Garole is the FecB (Booroola) gene mutation. This was originally described in Australia by Helen Newton Turner, in whose honour this workshop is named, and attributed by her to early importation of Bengal sheep. Using direct DNA tests for the presence of the mutation, the project team set about introducing (introgressing) the gene into an experimental flock comprising local Deccani sheep and their crosses with promising local meat breeds. This work suggested that the mutation conferred useful increases in fecundity and meat production efficiency. During 2003–08 this was confirmed in 26 collaborating smallholder sheep owners' flocks in which the biological and economic impact of introduction of the mutation was assessed. Use of the FecB gene is one of the few examples where DNA technologies have been shown to clearly benefit practical breeding programs. ACIAR is therefore pleased to be a major sponsor of this, only the second, international workshop dedicated to the FecB (Booroola) gene. The first workshop on 'The Booroola Merino' was held in Armidale (New South Wales, Australia) in 1980. The first paper in those proceedings was written by Dr Helen Newton Turner on the 'Origins of the CSIRO Booroola' and included the postulate about the Bengali origin of the gene. Between these two workshops dedicated to FecB, another two workshops on major genes in sheep were held in Toulouse, France, in 1990 and 2003, at which advances in understanding of FecB were also presented. Major developments over the 28 years since the first workshop include the discovery of the single gene origin of the fecundity effect, improved understanding of the physiological basis of the effect and the reproductive and economic consequences of this, and the development of methods for accurate genotyping of animals at the FecB locus, which culminated in the development of a direct DNA test. The FecB gene has spread from the Booroola Merino to some 40 4 breeds of sheep worldwide. It is now also spreading from the Garole, Hu and Han breeds in India and China, from one of which it probably originated. The workshop was attended by approximately 100 delegates and speakers from 13 countries and 9 Indian states. Invited speakers were largely drawn from researchers from around the world involved in major projects on the introgression of the FecB gene. The aim was that these proceedings would summarise our current understanding of the FecB mutation, with special emphasis on the biological and economic consequences of its use in new breeds for commercial reasons. These proceedings are testament to the achievement of this goal. They also include a summary of a panel discussion on recommendations and strategies for a wider introgression of the FecB gene into the Indian sheep population. These proceedings will be an invaluable resource for those involved in commercial use of the FecB mutation in any country. ACIAR is proud to have been centrally involved in much of the research reported at the workshop, and in its sponsorship and publication. The ACIAR Indian projects have provided some of the clearest evidence of successful commercial use of the FecB gene, and it can be expected that this will contribute to a substantial improvement in sheep productivity and smallholder sheep owners’ incomes in India.