Intra-uterine insemination, or deep insemination, could let you reduce the amount of boar sperm per dose, but it’s uncertain how beneficial it can be in the long run.

IUI refers to a method of artificial insemination, in which a special catheter is manipulated 10 to 14 inches deeper into the sow’s cervix than normal, until it reaches the uterine cavity.

Despite being pegged as an up-and-coming technology, IUI has not caught on in the United States. Less than 1 percent of all artificial inseminations are done via IUI, says Kevin Rozeboom, research and education director for Minitube of America. That number is not expected to increase greatly unless some things change.

“Semen costs and reproductive performance will determine the future of IUI,” says Don Levis, Extension swine specialist, Ohio State University. “If semen cost is increased and reproductive performance is similar to traditional AI, it is not beneficial to use IUI. If semen cost is lower and reproductive performance is similar to traditional AI, it is beneficial to use IUI. If you collect your own boar’s semen, at a lower cost per dose compared to purchased semen, then IUI might be economical.”

The big selling point for IUI is that it reduces the amount of sperm per dose. In fact it could double the doses you get from a boar ejaculate. Angela DeMirjyn, special projects manager for IMV International, says a normal boar ejaculate contains about 60 billion to 70 billion sperm cells, which produces about 25 doses with standard AI procedures. With a move to IUI, the same ejaculate could produce 45 to 50 doses, says DeMirjyn.

Extending each ejaculate into more doses lets you stretch boars further, allowing you to use fewer boars.

“Using IUI could allow you to use better boars, because you could buy five good boars rather than 10 average boars and get the same amount of service from them,” says DeMirjyn. “Using a narrower genetic pool may allow you to capture premiums for uniform hogs.”

Levis suggests the boar herd will continue to dwindle, and IUI could be a factor. He points out that if all U.S. sows were bred using natural service the breeding herd would include about 295,000 boars. If the country went to 100 percent AI, the breeding herd would only need to include about 17,500 boars. If the whole country moved to 100 percent deep insemination, fewer than 1,000 boars might be necessary, he says.

Reducing the total number of boars may increase efficiencies and uniformity, but there also is some danger in reducing the gene pool from a genetic standpoint. Fewer boars would increase the potential of inbreeding. Also, by limiting genetic variety you may unwittingly select for some negative traits. An example of this can be found in the sow longevity problems the industry has faced since selecting for leaner sows.

“Narrowing the genetic pool is dangerous, but it happens every day,” says DeMirjyn. “Anytime you single out lines for normal AI, bad traits sometimes surface.”

“Intra-uterine insemination probably has a lot of potential, but there are still some technical details to straighten out before the industry embraces it,” says Billy Flowers, North Carolina State University swine reproductive specialist. “A lot of questions need to be answered before IUI becomes common.”

Some of those technical issues might be construed as negatives for IUI. For example, IUI requires more care by AI technicians to avoid damaging the sow’s reproductive tract compared with regular AI techniques. Technicians will need to receive detailed training from the IUI equipment supplier. Both IMV and Minitube provide this service.

“Some people who are already good breeders can pick up IUI in 10 minutes, but you have to be careful,” says DeMirjyn. “Others are better with an IUI catheter than a regular AI catheter and some good AI breeders never get the hang of the IUI catheter. It really depends on the individual.”

Cost is another important consideration. The cost of the IUI catheter can run three times as much as a normal AI catheter and other costs, like labor can add up as well.

“The equipment cost of IUI per service is about $1.60, compared to $0.20 per service for standard AI,” says Rozeboom.

“Two big disadvantages of IUI include the fact that you can’t use it on gilts, and you can get a decline in reproductive performance,” says Rozeboom. “Since IUI can not be used with gilts, it is difficult to manage the production of semen doses and semen sales at the commercial boar stud. For example, you would need one dose concentration for sows and a different concentration for gilts. So, although boar studs may be able to reduce the number of boars they carry, in the end a dose of semen will cost the same if not more than it does today.”

Rozeboom adds that unless packers will add a premium for market-hog uniformity, there’s no economic advantage for producers to adapt IUI technology since it costs more and increases the risk of reproductive variation.

IUI’s reproductive performance may hold the answer to its future. Being able to use smaller doses of semen is of little use if farrowing rates or pigs-per-litter drop. Even if reproductive performance holds steady, the additional costs of IUI are likely to make it unfavorable to many producers.

Researchers at the Royal Veterinary College in London, showed that deep insemination using 2 billion and 3 billion sperm cells per dose had similar farrowing rates – all exceeding 90 percent – and pigs born per litter as standard AI methods. At lower dosages (1 billion sperm cells per dose), the deep insemination had an 89 percent farrowing rate, compared to a 66 percent rate with standard AI

“If you already have a 90 percent farrowing rate, I’m not sure what you might get by going to IUI,” says Rozeboom. “Currently, there’s not enough consistency using IUI to be beneficial to independent producers. Genetic companies are the ones that could gain from IUI.”

Purebred breeders are another group that could benefit, because the cost of superior purebred semen can be so expensive that the extra catheter costs and labor commitment are easily offset by semen cost savings, says DeMirjyn. Integrators and producers with internal seedstock multiplication programs could see positive returns from IUI as well, she adds.

Advances in other technologies might make IUI more favorable. For example, if frozen boar semen becomes more prevalent than fresh, and semen separation technology continues to advance, then it might gain popularity, says Flowers.

While, IUI is still an emerging technology, it could become a stepping stone to even deeper insemination – intra-uterine-horn insemination. Current IUI methods inject semen into the uterine body, which is about 14 inches from the uterus. With intra-uterine-horn insemination, semen could be injected within 5 inches of the oviduct, says Levis.

“With even deeper insemination it’s possible you might reduce the sperm dose from 80 ml to 90 ml for standard AI, down to 5 ml to 10 ml that contains 150 million sperm cells per dose,” says Levis.

Intra-uterine-horn insemination appears to have no additional risks to intra-uterine-body insemination, nor does it appear to effect the sow’s well-being, says Levis. No costs have been established for intra-uterine-horn insemination in the United States.

So far, it has only been practiced in Europe and Mexico, but a genetics company has bought the U.S. technology rights. Similar to intra-uterine-body insemination, intra-uterine-horn insemination could be more beneficial to a genetics company than to producers, as it could allow semen from a certain boar line to be used more widely in a shorter amount of time, says DeMirjyn.

The story on both forms of deep insemination is that they are emerging technologies that may some day catch on in certain niches, but are not yet ready to become commonplace in U.S. pork production.

“There’s still some basic information that needs to be discovered concerning how the sperm interacts with the uterine environment, before these technologies become common,” says Flowers.

He suggests that a comprehensive study over time that includes data on fertility and sow longevity needs to be conducted on both deep-insemination techniques before drawing too many conclusions.

“I can’t emphasize enough that these emerging technologies should be looked at with caution,” says Flowers. “It’s always dangerous to speculate how good or bad any new technology could be.” 

Helping You Make Tough Reproductive Calls

One tool that you can use to help evaluate whether deep insemination is now or may someday be a good fit for your operation is a spreadsheet that Don Levis, Ohio State University Extension swine specialist has  developed.

You can find it at Ohio State University’s  Extension Web site at: Spreadsheets/Intrauterine-AIform.xls -'UK Data'!J8

“Based on published research data, the insemination of sows with an intra-uterine-body catheter may or may not be profitable.  The computer template on the Ohio Pork Industry Center’s Web site will help pork producers determine the economic value of using an intra-uterine-body catheter on their farms,” says Levis.

He suggests paying special attention to farrowing rate, litter size and semen cost when using the program.