A Meta-analysis Study of Association Between FecB Polymorphism and Litter Size in Sheep
Abstract Litter size is perhaps the main commercial trait since it has an observable effect on benefit in the sheep industry. Fecundity genes, play a vital role in expression of litter size. One of the most popular of these genes is the Booroola gene (FecB). In many past researches there was a dependency between the BMPR1B gene polymorphism and litter size of sheep. In the current study, a meta-analysis directed by coalescing outcoming of 9902 cases of 26 published research wherein various breeds of sheep to assess the influence of the FecB gene on litter size utilizing additive, recessive, dominant, and co-dominant genetic models. The random effects model was used for data analysis according to the Cochran Q test and I2 quantity. Under additive (SMD = 0.528), dominant (SMD = 0.468) and recessive (SMD = 0.250) models, the significant effect (P<0.01) of FecB genotypes has been identified. Furthermore, under the co-dominant (SMD = -0.050, P = 0.3332) model, the association between FecB genotypes and litter size trait had not been detected. A growth in litter size by about 0.47 lambs (Dominant model) was associated with the first copy of the FecB gene and 0.25 lambs (Recessive model) with the second copy of this gene. Consequences of the current study support the idea that BMPR1B fundamentally influenced litter size and subsequently it may be utilized for Marker-assisted selection programmers for improved genetic merit of reproductive futures and furthermore insert this gene by crossbreeding in low prolific breeds may improve reproductive characteristics.