Genetic engineering is the use of molecular biology technology to modify DNA sequence(s) in genomes, using a variety of approaches. The rapid developments in the field of genetic engineering have given a new impetus to biotechnology. This book is aimed to cover research and developments on the sperm-mediated gene transfer methods that is gene transfer based on the spontaneous ability of sperm cells to bind and internalize exogenous DNA and to carry it to oocyte during fertilization, producing genetically modified animals with high efficiency. The success led to a new interest in transgenic technology because of its simplicity, although various methods have been successfully used to create transgenic animals. This book brings together theoretical and experiential reviews from experts in SMGT, providing comprehensive coverage of the major trends, developments and controversies in this novel field.