In vitro gene silencing by RNA interference technology is still a new concept, especially in the field of animal biotechnology or agriculturally important small ruminants like sheep and goat. This is the first time the authors reported an efficient and robust way of knocking down the Myostatin gene (knocking down of which will increase the muscle mass/meat) in Caprine fibroblast cell by using U6 promoter based vector and with four different 29 nucleotide shRNA combinations. An easy and effective technique of measuring the transfection efficiency of short hairpin DNA containing plasmids has also been documented. Two, out of four shRNAs are proved to be very efficient and they can be used in vivo for confirmation of the knockdown effect in living animal, as well as for production of a stably transfected cell line with “knocked down MSTN” for future research in this field. Hence, this work is an important contribution in Animal-Cell Biotechnology. An elaborate review of relevant literature and a step-by-step methodical explanation of the experiment with minute details are the extra assets of this book.