Collecting and handling semen is not a complicated process; however, knowledge and attention to detail is required at all stages of the task. Equine semen is very sensitive and if not handled properly will quickly lose its viability. The goal is to collect the best possible sample while ensuring everyone’s safety, and a technician’s role in this process is important from beginning to end.
If a stallion’s specific preferences and needs are not designated on an existing medical record, the veterinary technician should compile a medical file of this information for future collections. These include specifications for use of a phantom/mare, temperature and weight of artificial vagina (AV), extender and antibiotic preference, and whether the front legs need to be wrapped for protection. Determining how the stallion is handled at home provides the veterinarians with very important information.
Before the stallion arrives, warm the extender and antibiotics, stage warmer, slide warmer, and AV liner to 37°C (98.6°F). Wrap the phantom with plastic wrap to prevent possible disease transmission, and adjust it to the horse’s preferred height. Have a plastic bag-lined bucket ready with warm water for washing the penis. Label any cultures with the stallion’s name, veterinarian’s name, and site to be cultured. A technician that completes these steps helps the veterinarian use his or her time more efficiently during what can be a fast-paced event.
When the stallion and veterinarian are both present at the collection location, a well-trained technician proceeds with preparing the AV. Doing so carefully ensures no contaminants such as water or dirt are introduced, since both are spermicidal. The liner needs to be well-lubricated with a non-spermicidal lubricant and filled with appropriately warmed water, using a thermometer that is capable of registering 60°C (140°F). When using a Missouri-style AV, put a leather cover over the liner to keep the AV warm. Secure a semen collection bottle to the liner with a nylon filter inserted in the top, and cover the collection bottle to protect semen from weather elements.
While handling a stallion, safety is critical—not only for the horse but for all team members involved. Many technicians are very skilled and capable of handling a stallion for collection. They should also be calm, quiet, and consistent. With everything in place the veterinarian can then tease, wash, and collect the stallion.
Once collected, the semen is taken into the lab for processing and evaluation. The technician should already have the extender, with antibiotics in it, warmed to 37°C in the incubator. Handling semen in a timely fashion is easy when the technician has everything in place and in good working order. He or she should also maintain temperature logs and calibrate equipment.
Once the semen is in the lab and has been filtered, the technician can measure the volume of ejaculate and extend it 1:1. Place ejaculate on the prewarmed slide warmer or in an incubator to keep semen viable while performing other diagnostics. One small sample is used to perform a semen measurement; this tells you how many sperm per mL are in the ejaculate.
The veterinarian uses the second sample to look at the semen’s motility (quality of movement) on the CASA (Computer Assisted Sperm Analysis) equipment. This determines a progressive motility percentage, after which the semen can be divided appropriately, either for immediate insemination, for a cooled shipment, or to be frozen. Semen is divided depending on the total number of sperm in the ejaculate, the progressive motility, and the sperm morphology. If the collection is intended for a cooled shipment, the clinic should ship at least 1 billion progressively motile sperm per insemination dose. Immediate use can be artificially inseminated at a 1:1 ratio with extender or raw if desired.
A well-educated, trained, and reliable technician is invaluable to ensure things are in order and running smoothly. It makes a veterinarian’s day and the semen collection process much easier.