Porcine zona pellucida (PZP) immunocontraception of wild horses (Equus caballus) in Nevada: a 10 year study.
Porcine zona pellucida (PZP) immunocontraception was investigated for possible use in free-roaming wild horses in the western USA. A protocol of two injections (3-4 weeks apart) of vaccine lasting 1 year was first used and a single-injection controlled-release vaccine of 1 year duration was developed and tested in the field. Studies of a presumptive vaccine of 2 year duration were initiated. The parameters of anti-PZP antibody titre response, pregnancy testing and offspring production were used, and PZP vaccine was found to provide up to 94% infertility in free-roaming wild mares. In addition, a single-injection PZP vaccine of 1 year duration and containing a controlled-release component of PZP in a polymer matrix can provide infertility equivalent to the two-injection PZP vaccine. All the PZP vaccine preparations tested were associated with a return to normal fertility within 1 year. During the course of these studies, attention was given to practical aspects of management application of PZP contraception. Preparation of the controlled-release portion of the vaccine in pellets, which fit into the needle of a dart or syringe, has simplified vaccine handling and permitted long-term storage of the controlled-release component. Vaccine delivery is now performed using a jabstick on captured mares restrained in a field stock chute during routine horse gathers. Provision of a vaccine-training programme has maximized personnel safety during vaccine preparation and use.
Turner
J W
JW
Physiology and Molecular Medicine, Medical College of Ohio, Toledo 43614-5804, USA. jturner@mco.edu
Liu
I K M
IK
Flanagan
D R
DR
Bynum
K S
KS
Rutberg
A T
AT
D000818:Animals; D000835:Animals, Wild; D000941:Antigens / Q000008:administration & dosage*; D003269:Contraception, Immunologic / Q000379:methods / Q000662:veterinary*; D003692:Delayed-Action Preparations; D004527:Egg Proteins / Q000008:administration & dosage*; D005260:Female; D006736:Horses; D008562:Membrane Glycoproteins / Q000008:administration & dosage*; D009505:Nevada; D011155:Population Control; D011956:Receptors, Cell Surface; D013552:Swine; D013997:Time Factors; D022642:Vaccines, Contraceptive / Q000008:administration & dosage*; D000072216:Zona Pellucida Glycoproteins
D000941:Antigens; D003692:Delayed-Action Preparations; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D022642:Vaccines, Contraceptive; D000072216:Zona Pellucida Glycoproteins