title: Cryopreservation of bull semen: Evolution from egg yolk based to soybean based extenders.
abstract: Since the inception of bovine semen cryopreservation, egg yolk and milk based extenders have been used to protect sperm from the detrimental effects of cooling and freezing. In recent years, demand for alternatives to conventional commercial extenders has arisen as the risk of introducing exotic diseases through transporting egg yolk based products has been recognized. Egg yolk can also interfere with sperm evaluation and the presence of particulate material in the extender may reduce fertility. Soybeans contain lecithin, a phospholipid fraction that can substitute for high molecular weight lipoprotein and phospholipids from egg yolk and prevent or ameliorate damage to the sperm plasma membrane that occurs during extension, cooling, and cryopreservation. Soy lecithin based extenders have been evaluated for processing and freezing bovine semen, although extender from soybean milk has not been studied as extensively. Commercially available soy lecithin based extenders are used increasingly but remain under scrutiny and are not universally accepted. With these observations in mind, this review is intended to examine effects of conventional cryopreservation procedures, methods of assessment, and potential for developing soybean extract as an acceptable alternative to traditional egg yolk and milk based extenders for bull sperm cryopreservation.
authors: Livestock Research Centre, National Dairy Research Institute, Karnal, 132 001 Haryana, India.
authors: S S
authors: SS
authors: Layek
authors: Livestock Research Centre, National Dairy Research Institute, Karnal, 132 001 Haryana, India.
authors: T K
authors: TK
authors: Mohanty
authors: Livestock Research Centre, National Dairy Research Institute, Karnal, 132 001 Haryana, India.
authors: A
authors: A
authors: Kumaresan
authors: Department of Animal Science, Cornell University, Ithaca, NY 14850, USA. Electronic address: jep5@cornell.ed.
authors: J E
authors: JE
authors: Parks
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000737:chemistry / Q000494:pharmacology; D004530:Egg Yolk / Q000737:chemistry*; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013025:Glycine max / Q000737:chemistry*; D013081:Sperm Motility / Q000187:drug effects
chemical_list: D003451:Cryoprotective Agents
keywords: Bovine semen; Cryopreservation; Egg yolk; Extender; Lecithin; Soybean; Sperm