A company called Equine Reproduction offers information, services, and equipment for artificial insemination of horses and perhaps other animals. They host an online semen calculator. They explain some of the differences between different varieties of artificial vaginas, and in some cases identify the manufacturers. Here is their take on two of the many kinds:
Colorado style
- Retains water temperature longer in cold weather
- Is more durable under extreme use
- Liner is cheaper to replace when worn or damaged
- If not too long, allows the stallion to ejaculate well clear of the heated liner, thereby avoiding danger of sperm damage by heat shock
Missouri style
- Is cheaper to purchase initially
- Is lighter and therefore easier to handle when filled with water
- Will allow for the addition of air to make the liner tighter
- Allows a less direct manual stimulation of the penis, which can be preferable with some stallions