If you don't have experience with artificially inseminating pigs, contact a county extension agent or member of a pork producers associate for help.
Artificial insemination, or AI, is a very popular method of breeding swine. Most everyone employs this method these days, as it’s easy and cost-effective. A hobby farmer can purchase semen from a boar stud for $25 and up, so the financial investment is minimal if you aren’t too particular about the breed or boar. You can find boar studs across the country, and owners advertise their animals in catalogs, in swine publications and through pork producers associations.
AI is easy for a layman to do; you don’t necessarily need a veterinarian, though it’s always good to see it done first before you try it yourself. Your county extension agent or pork producers association members might be able to connect you to someone with AI experience.
The most critical aspect to successful AI is detecting when the sow is in standing estrus, or in heat, which means she’s ready to be bred. The sow’s average estrus cycle is 21 days but can range from 18 to 23 days. Most pig breeders will have a teaser boar or a bottle of pheromones to help detect when their sows are in standing estrus.
If you don’t have these at your disposal, the signs are easy to detect. When a sow is in standing estrus, she will have a different attitude and exhibit different behaviors. A good test for standing estrus is the response to back pressure. If you press on the middle of the sow’s back and she runs away from you, she’s not ready. If the pressure causes her to stand rock solid with ears perked up, she’s in standing estrus. Gynecological signs include a swollen vulva that’s often red in color and stringy mucus discharge from the vulva. If you can stretch this mucus between your thumb and forefinger a good 1/2 inch, she’s ready. The sow will remain in heat for the next 36 to 72 hours.
Once you detect standing estrus, contact the stud owner and ask for semen to be shipped. Prepare in advance for this, because if you want a specific boar, you may have to request the semen months in advance. If you’re not particular, you’ll have more immediate choices.
The semen will arrive in vials or bags in a temperature-controlled box at 58 to 60 degrees F. There will be 2.5 million to 3.5 million sperm, diluted in semen extender, in each bag. You usually breed a sow twice while she’s in standing estrus, so order two bags.
The semen is inserted into the cervix with a disposable insemination rod. Ask the stud owner if these are included with the semen order. Insert the rod, angling slightly upward, through the vagina until you feel resistance, which means you’ve reached the cervix. If you have a spirette-type rod, turn it counter-clockwise until it fixes into the cervix. Turn it clockwise as you remove it. If you have a foam-tipped rod, push firmly until the tip is locked into the cervix. Pull it down gently to remove it. Insert the second bag 24 hours later.
If the sow doesn’t come back into standing estrus 21 days later, she’s probably pregnant. Your veterinarian can perform an ultrasound 24 days from breeding to make sure. The normal gestation period for a sow is 116 days (three months, three weeks and three days), and she’ll have six to 14 piglets.
—Thomas G. Gillespie, DVM, Diplomate, ABVP, Swine Health Management Specialty of Rensselaer Swine Services in Rensselaer, Ind.; 2010 American Association of Swine Veterinarians Swine Practitioner of the Year
About the Author: Sharon Biggs Waller is an award-winning writer and author of Advanced English Riding (BowTie Press, 2007) and the upcoming The Complete Horse Bible (BowTie Press). She lives on a 10-acre hobby farm in northwest Indiana with her husband, Mark, 75 chickens, two Lamancha goats, two horses, and an assortment of cats and dogs.