Fertility Control Program Update
AWHC Fertility Control by the Numbers:
To date:
Total Records: 1023
Total Primers: 542
Total Boosters: 481
Total Horses: 703
Great job everyone involved! Thank you for your hard work and dedication.
How does PZP work?
The American Wild Horse Campaign funds the fertility control Porcine Zona Pellucida (PZP) program on the Virginia Range. PZP is a vaccine that prevents fertilization and is backed by 30 years of science and used all over the world on various animals from elephants, deer and of course wild horses!
PZP is created using pig protein. The protein causes the mares immune system to respond to the vaccine by coating the egg so that it cannot be fertilized during breeding. It is completely non hormonal and does not affect natural-born behaviors. The mare is given an initial dose called a primer which has a 97% efficacy rate, she then should have a booster in 2 weeks. Mares can also be boosted within the year of their primer which has an efficacy rate of 95%. Mares can be treated while pregnant without causing adverse effects on the foal and it does not pass to the mares milk. PZP is not a permanent sterilization tool and allows for mares to contribute to the gene pool, keeping wild horse bands healthy and thriving!
Below is a photo series showing how mares are identified, how the PZP is mixed, and how the mare is darted.