Livestock Production via Micromanipulation

Abstract

The use of micromanipulation techniques in the production of livestock mammals, focusing on intracytoplasmic sperm injection (ICSI) and the pig, Sus scrofa , is discussed in this chapter. ICSI is a powerful method for assisted fertilization. It is typically employed in cases in which semen characteristics are insuffi cient for conventional in vitro fertilization (IVF). Unlike IVF, ICSI mechanically delivers the sperm deep inside the egg cytoplasm by injection through a micropipette. We summarize the use of micromanipulation techniques in the production of livestock mammals, focusing on intracytoplasmic sperm injection (ICSI) and the pig, Sus scrofa . ICSI is a powerful method for assisted fertilization. It is typically employed where semen characteristics are insuffi cient for conventional in vitro fertilization (IVF), in which sperm and eggs are mixed and fuse in culture. Unlike IVF, ICSI mechanically delivers the sperm deep inside the egg cytoplasm by injection through a micropipette.Mammalian ICSI was fi rst demonstrated in hamster oocytes [ 1 ] and subsequently applied to humans to overcome impaired fertility [ 2 ] . In livestock, ICSI is also used as a procedure for fertilization, but its purpose is not restricted to impaired male fertility. Although circumstances do not ordinarily justify ICSI for breeding normal livestock, there are clear exceptions. Where sperm-containing ejaculates cannot be obtained, a small number of sperm may be obtained by biopsy, with ICSI as the method of choice for delivery into oocyte. Owing to its technical robustness, ICSI is especially benefi cial where the breeding male stock has high genetic merit. These applications are now considered in greater detail.