An Overview of A.I. in Dairy Goats
Published on Fri, 07/09/2021 - 12:18pm
An Overview of A.I. in Dairy Goats
By Jaclyn Krymowski
Traditional live cover tends to be the status quo breeding program protocol in many dairy goat herds, especially in the U.S. However, the continued advancement of reproductive technologies gives more opportunities for A.I. to proliferate and accelerate genetic progress in the industry. As A.I. and similar reproductive technologies have massively benefited cattle genetics, the same could translate to global and domestic dairy goat industries.
From an anatomy standpoint, there are some unique challenges that small ruminant managers face. However, unlike sheep, goats can be inseminated vaginally without the need for a laparoscopic procedure. While not being able to physically palpate through the rectum is a disadvantage that requires a skillful technician to overcome, the overall procedure is relatively simplistic.
Though A.I. is still relatively small in the goat world, the greater accessibility of technology and education is helping push it into more mainstream applications. Notably, A.I. has been making headway in nations around the world as they continue to grow and expand their goat industries, including throughout Europe and even the Philippines.
Tools and materials
The biggest difference in tools between A.I. breeding does and cows is the use of a speculum. This is a smooth tube (in some cases as simple as a small PVC pipe) that gently enters through the vestibule of the vagina and is pushed right up into the fornix, or the fold along the circumference at the start of the cervix.
This allows the technician a clear view to see the end of the cervix and the cervical os, or the small opening that leads to the uterus. Higher-end speculums come with a built-in light, but a small flashlight held in hand will also work just as well.
From there, it is simply a matter of pushing the A.I. rod through the os gently but firmly. Like with cows, there are cervical rings that may require a bit of maneuvering and gentle force to push through. With a loud popping sound, the technician knows they have entered through the other end of the cervix.
Unlike with cows, the technician can’t palpate a doe to know about how far into the uterus they are. The goal is to deposit the semen about an inch into the uterus which takes a bit of estimating in the case of goats. To prevent any semen from being accidentally deposited in the cervix, the plunger must be pushed fully before removing the rod.
With the work of a veterinarian, laparoscopic A.I. is another option that can have very successful results. However, it is an expensive and invasive surgical procedure. Deciding to use this method should be done with consultation and consideration of the particular animal.
Buck semen collection, storage and handling are about the same rules as seen in cattle. The same recommended procedures regarding nitrogen tank care, thawing and handling can be followed.
While the insemination process is simple enough, goats have another unique issue, that being they are seasonally polyestrous breeders. This means that does come go through multiple heat cycles but only during specific seasons – late summer through late fall in this case.
The limited window of breeding according to the natural season makes timing imperative and fixed time-A.I. procedures are a valuable tool. Inducing heat outside of the season can also be done with different effective options for dairies including regulating light exposure and traditional hormonal synchronization following an injection protocol.
While additional research is needed, much of the data on small ruminants indicates that synchronization protocols work best using progestogen implants or CIDRs. Because most of the hormonal products on the market aren’t labeled for goats, the use of them will be an off-label use and require the prescription of a veterinarian. Depending on the type of synchronization used and the individual animal, a doe’s standing heat usually lasts from two to three days.
Besides some behavioral cues, a good standing heat for a doe is indicated by the presence of clear mucus, usually very evident on the end of the speculum once removed.
Statistics and resources
Because goats are a minor species, data and statistics on conception rates are not widely available. According to one study, laparoscopic A.I. in ewes and does can have a conception rate as high as 60-80% - notably higher than traditional cattle fixed-time A.I. rates of 40-60%. There is data out there suggesting that the average cervical A.I. procedure has success rates from 50-70% in goats. However, this is hugely dependent on the skill of the technician, semen quality, semen handling and time of breeding. There is also variance in fertility among breeds and individuals.
While A.I. services and technicians for goat dairies are not as widely yet available in the U.S., there are still plenty of resources available for small ruminant producers. Many associations and extension services hold events to train farmers to do the procedure themselves. With time and practice, anyone can become skilled if using the right tools and methods.
The majority of goat semen sales are done online, however many goat breeders will host buck collections and sell semen directly off-farm. Regional goat associations and land grant universities with small ruminant programs are also good resources to consult with.