of AI and pigs
A little homestead tech for genetic improvement of your hogs
What kind of AI did you think we were going to talk about? Is that heading a little clickbait-ish? Maybe. Sorry, not sorry. :) Glad you’re here though!
This kind of AI is WAY more interesting than artificial intelligence. I mean, its end result is bacon…soooo, nuff said, right?
Domestic pigs are “officially” classified as non-seasonal breeders, as well as polyestrous. Insert a big HOWEVER right here, because if you’ve had much experience raising pigs in a homestead setting, you know there are a couple times of year when gilts & sows seem to be beside themselves, in wicked raging heat.
This (late winter) is one of them. And thus our current dive into how artificial insemination can benefit your homestead, and how you can DIY & get those bacon seeds started.
Field Artificial Insemination of Homestead Sows & Gilts
I talk about artificial insemination in much the same way Joel Salatin talks about electric fencing. In a lecture at Cornell University, he said, “We look at nature as a template, place it on our commercial system, and see how we can best reproduce it.”
Mobile electric fencing is a technology, however basic, that he advocates to reproduce the mob grazing patterns of herds of hoof stock across vast expanses of grassland. It’s not complicated, it’s relatively inexpensive, is scalable, and it works. With respect to swine, artificial insemination also checks those boxes and reproduces, well…reproduction. It’s also a rather basic technology, and can prove a potent tool in your homestead tool box.
Why not just use a boar?
Natural cover is ideal. The boar is by far the most superior heat detection device, and sows will more efficiently breed when exposed to boar versus artificial insemination. If you’re able to keep quality boar and sustainably maintain him in separate accommodations in the off season, then by all means, do.
Furthermore, I always advocate for sourcing whatever you can from fellow farmers. Semen supply companies are huge & centralized, and it can be tedious to wade through catalogues of “show pig boars” until you find the kind of genetics you’re looking for. I envy folks that live in areas graced with several other conscientious breeders of heritage hogs. In those scenarios, AI need only be employed to introduce new genetics to the region. That, however, is not the case in my locale, and may not be in yours, either.
Here are some considerations that may help you decide if AI is right for your sows this season:
Genetic diversity - We raise heritage Berkshire hogs, and finding quality genetics that are compatible to our phenotypic standards is dang difficult in our neck of the woods. We need hearty, tough pigs well suited to our hilly, rocky terrain. I want deep bodied, well-baconed, old-world, fat, pigs - which local Berks are not. Unfortunately around here, the ultra-lean, body builder "fair pig" is the standard body style. If you find yourself in a similar situation, shipping a box of semen may be a preferable option to shipping a whole boar from afar.
Replacement gilts - If you’re keeping replacement gilts, you would be needing to introduce a new boar every 2 years anyway to prevent sire-daughter mating.
Furtherance of quality, heritage breeds - I cringe at the prospect of losing amazingly unique, heritage breeds of any species livestock. I love that many folks have picked up the torches of Gloucester Old Spots, Tamworths, and the like - deciding that those breed characteristics pair well with their homestead settings, and committing to preserving the breeds. But again, one can quickly run into a situation where there are few to no boars locally, and would need to turn to importing semen to the farm.
Maintenance of a boar - A boar will need to be separated from the sows periodically. Thus, you will need sufficient facilities to do so. Pigs are veritable wrecking balls when shoddy fencing is combined with a sudden urge to be on the opposite side of the fence - an urge which an in-heat sow will readily provide. You’ll need to decide if investing the time and money into boar housing is worth it in your situation.
What to do with him when he’s done his job? Is your boar going to be a terminal sire, meaning, are all of his offspring destined for the freezer and sale? If so, a boar may serve your sows well for many years. However, if you’re keeping any of his female offspring, you’ll need a destination for him when his breeding days are over (at least on your farm). Do you have a viable outlet for boars of this breed locally? Do you enjoy boar meat?
Some boars are jerks - ‘Tis true. Not all, but a good portion of them turn into real knuckle heads. I personally don't want animals I have to worry about my kids or farm visitors getting too close to, and I don't want to have to carry a sidearm when my sows are in heat in case a boar decides to indulge his omnivorous tendencies. :) So in our situation, nasty boars don’t last long.
Are you ready?
So you’ve weighed your options, and perhaps you’re thinking AI sounds like it may be a kinda’ nice way to go this season (or next). But how to get it done? Do you need a vet? A bunch of specialized equipment? A huge upfront investment?
Nope, nope, and nope.
Artificially inseminating pigs is not difficult, nor highly technical. It can be made difficult and highly technical, but it’s just not necessary. As with any new skill, it takes practice to become proficient, but as you’ll see - it’s really quite straightforward and achievable in a homestead setting.
We are going to go stepwise through:
What you need to perform field AI on your farm
Semen handling & storage
How to time your gilts & sows
How to artificially inseminate a pig
Supplies
The instruments necessary for field insemination are simple!
1.) Insemination spirette - a long, plastic tube with a corkscrew-like component at one end, and an adaptor that will fit the semen bottle on the other. These can be obtained from your large-animal veterinarian, or may be ordered from most semen suppliers at the same time you order the semen.
2.) Sterile, non-spermicidal OB lube - a big blob of this goes into the end of my palpation sleeve where the end of the spirettes will sit. Have pity on the gal...don't try this without copious amounts of lube. All parties involved will benefit.
3.) Palpation sleeve - this is simply to keep the spirettes clean and protected & to keep the ends lubricated. You won't actually be wearing it...I guess you could if you're grossed out by this business, but you don't need to :) I keep the sleeve of spirettes in my coveralls to keep the ends warm until use.
4.) Clean rag or stack of paper towels, wet in warm water (I carry this in a little plastic baggie in my coverall pocket to keep it warm) - this is for cleaning the sow's vulva prior to inserting the spirette
5.) Optional - boar scent or a "teaser boar" - some folks have better success with these stimulants for the sow.
6.) Semen (see below)
7.) Snacks - not for you, silly :) For the sow. Having trained dogs for 30 something years & kids for half of that, I've learned the value of positive reinforcement. So the sow's get rewarded for not being nasty b's & for cooperating with my shenanigans. Hence the apples in the picture.
Semen Handling & Storage
An amazing thing about boar semen is that it stays viable for 5-7 days (I’ve looked at some under a microscope at 10 days & still saw swimmers!), as long as 4 basic conditions are met:
1.) Semen is properly extended - When a boar is collected, the semen will be split into several “doses” and then mixed with an “extender”. The extender is a fluid that essentially feeds the cells and provides a suspension in which they’ll be delivered to the sow. Companies like Swine Genetics International are pros, and they do a great job getting robust semen to their customers within about 24 hours of collection.
2.) Protection from UV - UV is an excellent sterilizer. So it’s vital to keep the semen away from UV exposure.
3.) Temperature control - Boar semen likes to live at 61-64 degrees F. I have 3 locations in my house that stay around that temperature. I’ll use cool packs from the fridge if further cooling is needed. I leave the tubes of semen in the same packaging I receive them in for insulation. Something akin to a wine fridge would be a little more sophisticated, but an insulated chest & a digital thermometer work fine for me.
4.) Periodic rotation/mixing - The sperm cells will settle to the lowest point in their vials, which will starve those at the bottom of the pile. So they need to be gently rotated & remixed with the extender every 6-12 hours until use.
Heat Detection
Tracking a sow's estrus cycle is both the most important, and the most difficult, part of the artificial insemination process. As I’m constantly preaching: it’s vital that you develop the habit of watching and knowing your animals. The Visual Examination, i.e. the skill of visually evaluating your animals, is the single most valuable animal husbandry habit you can possess.
Semen isn't cheap - with shipping, it can easily cost $200-$300 to breed one sow. So with that in mind, and the fact that we want to inseminate with the freshest semen possible, it's of the utmost importance to be confident in when she will be in standing heat.
I will try to track and document heat cycles in my sows for at least 2 cycles before ordering semen. A sow/gilt will come into heat approximately every 3 weeks, but it can be every 16-28 days depending on the animal. So that means, for about 2 months before I'm ready to have my sows bred, I will be jotting down signs of heat, standing heat, and dates, so I know when to have the semen at the ready.
Standing Heat
Also known as estrus, “standing heat” means that the gilt/sow is fertile (ovulation occurring & preparing for fertilization). Female pigs are most helpful to us, in that when they are most fertile, they literally stand when pressure is applied to their lower back.
Gilts and young sows will display more obvious signs of heat than older sows. In general, what I look for in a sow that's coming into heat is:
-grumpiness
-isolation from the rest of the herd
-restlessness & wandering around the enclosure when the rest of the pigs are at rest
-swelling of the vulva (more obvious in gilts)
- +/- vulvar discharge
-mounting other pigs, or allowing herself to be mounted
When I start to see these signs, I will begin testing them for "standing heat". A gilt/sow MUST be in standing heat to be bred - there's no use in breeding them if they're not standing, as you will miss their ovulation.
***This is KEY: A sow is in "standing heat" when she will lock her legs, stand in one place, with ears forward and erect in response to pressure placed on her lower back. This is THE sign of pending ovulation, and our cue to artificially inseminate pronto. Pretty cool, huh? No other species is quite so accommodating.
Sows will be in standing heat for 24-36 hours. So it's important to be checking them every 6-8 hours when you see the first signs of heat, in order to define that window for each sow.
Business Time
So you've zeroed in on your sow's heat timing & have semen at the ready. Time to AI.
You have 24-36 hours from the beginning of your sow's standing heat until the breeding window shuts. When she's no longer standing, that window is closed until the next cycle. I've had best success with 2 breedings per sow: the first when I initially appreciate standing heat, and the second 12-18 hours later (always less than 24 hours later).
The process:
It's important to keep weight, of some sort, on the sow's lower back during the spirette placement process. I achieve this by leaning over her with my left arm and resting most of my weight there.
1.) Use your warm rag to clean around the vulva area, so the spirette isn't dragging dirt, feces, debris, etc. into the reproductive tract. Clean until there is no more visible soiling of the rag.
2.) Insert the spirette, gently turning it counterclockwise to the sow while advancing. Keep a slight upward traction on it to avoid catching it on the urethra.
3.) The counterclockwise turn matches the spiral of the sow's cervix. When you can no longer twist it, let go of the spirette & it should make a slight clockwise correction, assuring you that it's in place.
4.) Remove the twist-off end of the semen bottle and attach it tightly to the opposite end of the spirette.
*I find that once the spirette is in place, a sow will usually stand without continued pressure on her lower back. So at this point, I'll usually rotate around so I can better see what I'm doing.
5.) Gently squeeze the bottle, emptying the contents through the spirette. Sometimes a sow's own uterine contractions with aid with uptake. Go slowly. This may take 1-2 minutes.
6.) When the contents have been emptied, leave the bottle on the end of the spirette or put the stopper in the end, then gently remove by turning the spirette counterclockwise.
7.) If the sow's been cooperative, then I'll usually give a reward like an apple or a banana. Positive reinforcement helps train these very smart animals to be receptive to your AI efforts.
And there you have it. Not quite as daunting as it may seem, right?
Document breeding dates and times, and watch for signs of heat returning when you'd expect her next cycle (approx. 3 weeks).
Signs of heat in 3 weeks = she didn't take
No signs of heat in 3 weeks = bacon seeds successfully sown (in most cases)
Artificial insemination isn’t right for every farm, every season. However, it can be a powerful tool for diversifying your herd, giving you options when a boar isn’t one. Let me know if and when you try it, what your results are, and if you have any remaining question marks regarding AI or swine reproduction in general.
While I love my friends & the personal emails/texts I get regarding recent posts, I encourage y’all to post your questions right here or in the Chat linked to this post, as there are likely other folks with the same ones, who are just too shy to ask ;)
Cheers!
“I’d marry ya, if it wasn’t for the 🐖’s” 😆☺️ Great article sis. I may need to learn how to do this sooner than later.