By Doug Groth, DVM, Carthage Veterinary Service Ltd.
Every day sows are bred at the sow farms, but have you ever thought about where the semen comes from? Studs are spread out across the countryside but usually close, within driving distance, due to the need to still use fresh semen. One 400-head stud can service up to 120,000 sows! This puts studs in an interesting position to balance location and biosecurity.
In the real estate world, location, location, location are the words to live by. This is true for the boar stud as well. Locating as far away from pigs is very important to reduce risk. Sometimes, what was once a well-located site, may have new swine facilities built close and now compromise a good location. That is when the implementation of the latest technology is important for ventilation. Air filtration has been the norm for most studs but now air conditioning with positive pressure! Yes, air conditioning!
Air conditioning has helped to address the summer heat stress in boars that affects semen quality and thus increases collection trash rates. The heat stress in studs usually double or triple normal trash rates so you could have 20-40% rates. This is very costly to a stud since it must carry extra inventory to cover through the summer production. AC has helped to reduce this affect through reduction in humidity and temperatures in the studs. It also has a nice boost to employee morale.
AC units are set up with 100% fresh air intake. This is less efficient than a house but allows very good longevity to the AC coils that can’t handle pit gases. Filters are integrated into the AC units. AC units now reduce your need for a high volume of air to be filtered since the barn will run close to minimum ventilation rates all year long. Filter needs also drop to 10-20% of conventional filtered barns. This also means less air to worry about as a source of contamination.
Positive pressure ventilation is also part of the systems. Controller technology has come along and is able to handle temperature and pressure in the barns. Maintaining positive pressure is a key part of air biosecurity. The system compensates for an open window or opening a door to ship culls out. Air is always flowing out. Controllers also now can be remotely monitored on your cell phone. Adjustments and quick checks can now be easily done. This is important since ventilation rates are now reduced and maintaining minimum air flow is important.
Fresh semen poses inherent risk to transfer diseases as well. Semen collections are living specimens so great media to keep infectious agents alive. Collection and lab technique at studs are the first line of defense to protect against contaminating a collection of semen. Training of employees never stops and auditing the process helps keep everything on track.
Semen extenders have also evolved to help maintain semen over longer time periods and contain preservative levels of antibiotics. New extenders are being tested to go without antibiotics by storing at colder temperatures to prevent bacterial growth. It is important to remember that preservative antibiotics or cold storage temperatures will have no effect on viral contaminants in semen.
A boar stud can do everything right to protect against disease introduction, but it still must get the semen to the sow farms. Transportation is the last critical part to verify. Semen couriers usually have set delivery routes daily and may go on different routes on alternating days. Studs double-bag semen orders at the stud to help eliminate transport risk if the outer layer is removed as it is introduced to the sow farm.
Couriers go through biosecurity training as well. Maintaining a clean vehicle interior and washing vehicles daily are a must. Couriers will also wear disposable shoe covers and gloves at pick-up of semen at the stud and at each delivery. One of the updates to vehicles has been the use of Yeti or Yeti-like coolers for holding semen during delivery. This cooler technology has been beneficial to keep constant temperature through the delivery process that may take several hours. They are also easy to clean and maintain.
Courier vehicle housing is also considered part of the biosecurity plan. Winter is the most critical since the vehicles are washed daily. Getting them dry is critical to biosecurity so having heated facilities to store the vehicle becomes important. If the vehicle has frozen material that stays with the vehicle, whatever is in the ice, now is able to move from stud to sow farm to sow farm. It is important to remember how veterinarians store infectious agents for future use/diagnostics — they freeze them. The other good that comes from heated garages is that transport coolers are already at a good temperature, not frozen and ready to take semen shipments.
Semen drop points at sow farms are another focal point. These drop points should be well maintained, clean and easily accessible to the couriers. Every sow farm needs to be a “good neighbor”. Meaning they don’t want what the previous farm has, and they shouldn’t want to give what they have to the next sow farm. A temperature-controlled drop point is ideal but not required. If there is an off-site drop, Styrofoam coolers are best to receive semen shipments. Styrofoam does not take on the extreme temperature, so is a fairly temperature-neutral object. Sanitation is the only challenge so routine replacement is a good plan.
Protecting the U.S. swine industry is a priority that we all must do our part to succeed. Boar studs are right in the heart of production. They may be small in size, but they touch thousands of sows, multiple times every week. Training employees and auditing ventilation and courier routes are critical points at the studs. Boar studs continue to improve and evolve with technology to protect and improve their product. Every sow farm must include their semen provider when thinking about biosecurity.