Myostatin (MSTN) belongs to the transforming growth factor (TGF)-β superfamily and is a potent negative regulator of skeletal muscle development and growth. Dysfunction of MSTN gene either by natural mutation or induced through genetic manipulation (knockout or knockdown) has been reported to increase the remarkable muscle mass in mammalian species. RNA interference (RNAi) is the most promising method for inhibition of gene expression that can be utilized for MSTN gene knockdown by developing short hairpin RNA (shRNA) construct against it. We utilized three antisense RNA expressing vectors with six constructs to knockdown MSTN gene in in vitro caprine myoblast cell culture system. We observed that all six shRNA constructs were successful in MSTN silencing with efficiency ranging from 7 to 46 % by quantitative real-time PCR and up to 19 % by western blotting. The significant upregulation of interferon response gene OAS1 (5- to 11-fold) in cells transfected with shRNA constructs were indicative of induction of interferon response. This RNAi-based method of increasing muscle mass could provide an alternative strategy to gene knockout methods for improving the production traits and economic properties of livestock.