Source: Four Star Veterinary Service
Why should a beef or dairy producer consider embryo transfer?
Traditionally speaking, most producers have used bulls for reproduction services with their cows. The difficulty with using bulls for reproduction is that for half the year, they must be kept in a separate pen and they’re difficult to move and to work with. Plus, they’re expensive to maintain for use a couple of months out of the year.
The industry has moved toward artificial insemination (AI), which is a real positive because producers no longer have to house their bulls, and it allows producers to select specific genetics on the sire side. However, it does not affect the maternal side.
Embryo transfer allows hand selection of both the sire and maternal sides. It allows producers to improve herd genetics at a much lower cost than buying the actual animal and trying to breed those animals onsite. Whereas if a beef or dairy producer can purchase an embryo and put it in one of his/her own cows, it can allow for a faster, more affordable build-up of your genetic program.
How important is building up the genetic profile in your herd?
In the beef, dairy and even show cattle industries, embryo transfer has really taken off. In the show industry, they’re looking for distinct genetics in the show ring with specific features. For beef cattle, it’s focused on weaning weights, market weights, carcass weights, marbling scores, etc. And for dairy cows, the main target is pounds of milk per day.
How can a producer transition from using a herd bull to implementing embryo transfers? Where do they start and what does the process look like?
The first and most important thing is excellent communication with the veterinarian that you want to do the service with. Embryo transfer takes a lot of planning and organization for things to go smoothly.
Communicate with your veterinarian about what your expectations are starting with calving dates and then work backwards from there to make sure timing works out well and that they’re available to assist during the process. Then it depends on what kind of herd you have.
Embryos IN. If you only have cows that you’re wanting to put embryos into, then it’s going to start with putting embryos into what we call “recips” or recipients. To begin that process we’ll do a synchronization protocol that will synchronize their estrous cycles similar to when you’re doing artificial insemination (AI). This depends on what protocol you choose to use. It may be based on veterinarian preference, or it may be what works best for your farm. One of the more common is called the 7&7 Synch protocol, and that’s about a 24-day process of timed injections. Again, it requires a lot of planning in advance.
Embryos OUT. If you have some cows that are special that you want to get embryos out of, it’s going to be a longer process. You’ll start with a synchronization protocol as well as an additional three to four days of FSH injections which induces the cow’s ovaries to ovulate multiple times before you AI. Then seven days later, you’ll flush the uterus and collect those embryos. So, it’s about a 31-to-32-day process. Once you have the embryos collected, you can either transfer them fresh into other recipients that you have also synchronized, or you can freeze the embryos for a later use in your own cattle or you can sell them to someone else.
There are cow side decisions to make too, correct?
Genetics works on two ends, and it depends on what genetics you currently have in your herd. If there’s not anything that you necessarily want to replicate or continue in your herd, then you’re dealing with just one side and can start fresh with embryo transfer. However, if you already have a high genetic herd and you want to cycle that, then you’re working with two different sets of cows.
What are some of the tips for a successful transfer?
- Vaccination timing. With vaccinations, modified live vaccines can cause significant issues in your reproductive rates with embryo transfers. Make sure those are given far enough in advance to ensure it’s not affecting your pregnancy rates.
- Nutrition program. Nutrition can be a huge issue. It’s especially important to loop in with your nutritionist when you’re trying to get this program implemented, especially if your herd is struggling with nutrition. For example, one of my mentors was having a poor day transferring embryos, and he was talking to the client who had just changed his nutrition program. It turns out they had a 0% pregnancy rate that day just due to the poor nutrition.
- Skilled labor. Another factor is the quality and dependability of labor involved with giving injections for the synchronization protocols. It’s extremely important for those embryos to be implanted at the right time to get pregnancies out of them.
- Planning and timing. It is extremely important to get the timing of the injections right. We’re trying to synchronize donors and recipients to be at the same stage of their cycles. That way when you implant these embryos, the same age of embryo is being implanted in a cow that’s in the same stage of her cycle.
- Quality recipients. The overall quality of your recipients is critical, so proper backgrounding of your recipients is important to ensure good body condition. People tend to focus more on the donor side because that’s the genetics that you’re trying to replicate. However, if you don’t have quality recipients from a fertility standpoint, you’re not going to have a successful program.
