In order to enhance breeding progress, genes that affect the performance of sheep are being identified. In Poland, sheep breeding programs focus mainly on meat performance, therefore, it is important to identify genes that affect it. Moreover, studies on reproductive performance of sheep have been made. Myostatin (GDF8), calpastatin (CAST) and calpain have been identified as the candidate genes affecting meat quality. Whereas, BMP15 and GDF9, also called fertility genes (Fec), have been reported to affect reproduction traits. The knowledge of the association between the polymorphic forms of these genes and sheep performance traits may contribute to the determination of genetic markers that could be used in sheep breeding programs. The aim of this study is to gather the latest information about the use of genomic selection in breeding programs and the association between polymorphisms in BMP15, GDF8, GDF9 and CAST genes and sheep performance.
