The journey a unit of semen takes from arrival at the farm until placement in a cow is very important. Maintaining maximum fertility weighs heavily on the care and handling it receives from all members of the management team.
Fortunately, this is one of the variables in reproductive success a farm has complete control over.
Individuals who have gone through A.I. training will be familiar with the do’s and don’ts of handling semen. But there are lots of common pitfalls on a day-to-day basis anyone can fall prey to. Understanding them and how to avoid them helps ensure you get the most out of your genetic investments.
Why handling matters
Through the years, the dairy industry and academia have amassed a wealth of knowledge on the best methodology to collect, stabilize, extend, freeze, package and maintain semen for maximum fertility.
During live cover, a bull will normally ejaculate about 4 to 5 billion sperm cells, but a normal straw contains only about 15 to 20 million, which is why proper placement by the technician is so important. Processing safeguards the sperm cells through a single freeze and thaw. However, frozen semen is extremely sensitive – and once thawed, the process cannot be repeated.
“When a breeder is removing a straw from the tank to thaw it, the focus is usually on the one to be retrieved,” says Dr. Joe Dalton of the University of Idaho. “We forget that if we lift the cane too high in the neck of the tank, we’re actually causing damage to the straws we don’t remove at that moment.”
If the goblet is held above the frost line for more than 10 to 15 seconds each time a unit is retrieved, the remaining units suffer more and more exposure stress each time. This means when you get down to the last unit, it will be the least fertile due to accumulated damage.
Likewise, proper thawing is also crucial to preserving the integrity of the sperm. All U.S. semen currently marketed can be thawed in a standard warm water bath at 95ºF to 98ºF. There are some companies who have a process making their units capable of pocket thawing.
Dalton says it should be noted only semen specifically marketed as being capable of pocket thawing can be done this way. Otherwise, the 95ºF to 98ºF range needs to be maintained from thaw bath to insemination.
“Essentially, we want to maintain that temp in an assembled gun. For the most part, our own body temperature is very close,” he says, noting that even in a warm environment, live semen should take no longer than 10 to 15 minutes to breed.
However, in cold weather when a gun is placed away from the body, for example in the outside pocket of coveralls, the temperature can drop very quickly. In these climates, warm battery packs are effective tools.
The team effort
Implementing best handling practices only works with contributions from everyone involved on your breeding team. Kayhart Brothers Dairy LLC in Addison, Vermont, credits their very dedicated team of employees who put in the hard work necessary for successful pregnancies.
The dairy is comprised of 1,200 lactating cows and 850 youngstock. In 2019, the herd was recognized by the Dairy Cattle Reproductive Council with Platinum honors for exceptional pregnancy rates.
“We attribute our success to our people first and foremost,” says Steve Kayhart, who owns the dairy with his brother Tim. “It has always been a team effort that has led to our success.”
Their A.I. team is headed up by herd manager Gene Pouliot, assisted by Courtney Banach and Kevin Stocker.
“Courtney does herd work at our new dairy and assists with a lot of timed-A.I. injections and all computer entries for breedings and pregnancy diagnosis reports. Kevin is a new addition to our team; he does relief herd work and also breeds cows whenever he gets the opportunity,” says Kayhart. “Gene came to us after a successful 27-year career breeding cows professionally. He is an excellent teacher and does most of the on-farm breeding and training.”
Additionally, the team meets quarterly with breeding company representatives to monitor genetic progress and evaluate overall performance.
A working team with designated roles, they excel in a recurring theme in reproductively successful herds.
“I say to my schools, ‘It’s good to have one or two people on each farm be really good at breeding,’” says Dave Watt of COBA Select Sires, who has led dozens of A.I. schools. “With a larger herd, you may need significantly more, but both PCDart and DairyComp have breeding triggers where you can always look at that one very easily and see if there’s a technician lagging behind or not and, if there is, then we make sure we spend more time with that person.”
Individuals dedicated to reproduction can also help the breeding process go smoother and increase fertility, even if they aren’t the ones actually breeding.
For example, if there are many cows waiting to be serviced, you should only have as many rods on you as you can breed within the 10- to 15-minute timeframe. Likewise, the thaw bath cannot be overwhelmed with units to the point the temperature drops.
“Part of the discussion is how the number of cows to be inseminated never allows you to break any rules,” Dalton says. “You need to think a little differently and maybe have someone else out there who can thaw straws, load guns and then give them to you to breed cows. This is very commonly done by a lot of farms who have these procedures and strategies in place.”
Maintaining equipment
How equipment is maintained and kept also plays a significant factor in maintaining semen integrity. “I always preach that you should keep your A.I. equipment like it’s medical equipment,” says Watt. “You’re trying to do everything you can to keep the uterus as clean as possible.”
Falling into this category is thaw bath water, which Watt notes should be changed several times a week. Not only does this keep the straw sterile, it also ensures water is being kept at optimal temperatures.
Nitrogen tanks also need to be monitored on a very regular basis. Kayhart says on their dairy, they typically have theirs filled about twice a month and refilled every two months. They also keep less than 30 days’ worth of inventory on hand at any given time.
Checking liquid nitrogen levels with a yardstick is a very simple way to safeguard inventory, but even with regular services, you want to make sure your tank doesn’t go dead unexpectedly. Other forms of prevention include keeping the tank off concrete, on a wood or rubber surface, and careful handling to avoid outer shell damage.
Following good semen-handling practices are simple and generally common sense, but they do require regular attention to detail and properly trained technicians. Ensuring they are part of the day-to-day on-farm protocols is a bit of cheap insurance so your genetic investments are getting the chance they deserve.
