Porcine zona pellucida (PZP) is the

zona pellucida The zona pellucida (plural zonae pellucidae, also egg coat or pellucid zone) is a specialized extracellular matrix that surrounds the plasma membrane of mammalian oocytes. It is a vital constitutive part of the oocyte. The zona pellucida first ap ...

extracted from the ovaries of

pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus s ...

s which is used as a source of

antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

s for

immunocontraception Immunocontraception is the use of an animal's immune system to prevent it from fertilizing offspring. Contraceptives of this type are not currently approved for human use. Typically immunocontraception involves the administration of a vaccine that ...

. The zona pellucida is a thick membrane that surrounds the unfertilised eggs of mammals. In order for an egg to be fertilised, sperm must first bind to, and then penetrate the zona pellucida. When porcine (pig) zona pellucida is injected into other mammals, antibodies are produced which attach to that animal's zona pellucida, preventing the sperm from attaching to the egg, therefore preventing fertilisation. Porcine zona pellucida has been used in

wildlife contraception Wildlife contraceptives are contraceptives used to regulate the fertility of wild animals. They are used to control population growth of certain wild animals. Usage White-tailed deer may be controlled with contraceptives in suburban areas, wh ...

since the late 1980s. Animals with which PZP has been employed in this context include

elephant Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae a ...

s, wild and/or feral horses,

elk The elk (''Cervus canadensis''), also known as the wapiti, is one of the largest species within the deer family, Cervidae, and one of the largest terrestrial mammals in its native range of North America and Central and East Asia. The commo ...

and whitetailed

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the rei ...

. It can be administered to captured animals via a standard syringe or administered to free ranging wildlife with a

dart gun A dart gun is an air rifle that fires a dart. The dart is tipped with a hypodermic needle and filled with a tranquilizer, vaccine, or antibiotic. A dart gun containing a tranquillizer is called a tranquillizer gun ( also spelled tranquilizer, tr ...

. The contraceptive effect last for approximately one year in horses, and can potentially be extended by including a controlled-release PZP component.

References

Mammal female reproductive system Veterinary drugs {{veterinary-med-stub