How to Know When a Sow Is Ready to Farrow: What 30 Years of Night Shifts in the Farrowing House Taught Me

The first sow I ever lost to a bad farrowing was a quiet, good-natured gilt, and I lost her because I went to bed. She had shown a little swelling in the udder and seemed restless that afternoon, but I told myself she still had days to go. At two in the morning I heard a sound from the pen that I have never forgotten. By the time I got there, she had been straining for hours, three piglets were dead, and the rest were in trouble. I had read the signs wrong and paid for it with a whole litter and almost the sow herself.

Here is the direct answer. A sow is getting ready to farrow when you see a combination of signs that build over the last few days and then sharpen in the final hours. Her belly drops and her udder fills and turns firm and warm. Her vulva swells and reddens. She starts building a nest, pawing at the floor and carrying bedding in her mouth. She becomes restless, eats less, breathes faster, and may pass small amounts of dung often. The strongest sign that farrowing is hours away, usually within a day and often much sooner, is milk that can be squeezed from her teats, along with nesting behaviour that has turned frantic. Once she lies on her side, breathing in deep, rhythmic effort with her tail twitching, the first piglet is usually minutes away.

No single sign is enough. You read them together, and you read them on a sow you know the due date of. Let me take you through how I do it.

Start With the Calendar

The gestation of a sow is roughly three months, three weeks, and three days, which most farmers round to about 114 days, though anything from about 112 to 116 is not unusual. Everything else I tell you sits on top of the calendar, not in place of it. If you did not record the service date, you are guessing from the start, and I will say more about that below.

I write the service date on a card on the pen and also in my notebook, and I count forward to the expected date as soon as the sow is served. Then I move her into the farrowing pen several days before that date, not on the day, so she can settle in and get used to the place. A sow moved in at the last minute is stressed, and a stressed sow can delay farrowing or farrow badly.

What Most Farmers Get Wrong

The first mistake is relying only on the calendar. Sows do not read calendars. I have had sows go early and sows go late by a few days, and a farmer who trusts the date alone will be asleep or away when the sow decides to go.

The second mistake is the opposite one, relying on one sign. A swollen udder alone can appear a week or more before farrowing, especially in a gilt. If you hear that a sow is about to drop because her udder looks full, and you stay up three nights in a row waiting, you will be too tired to help when it matters.

The third mistake is leaving a sow with no bedding or nesting material. Sows have a strong urge to build a nest in the last day or so before farrowing, and one that has nothing to carry and nothing to paw at becomes anxious. That stress can make farrowing slower.

The fourth mistake is a noisy, busy, or disturbed farrowing area. Strangers, dogs, children, and loud work near the pen can interrupt a sow in labour. A disturbed sow can hold back the birth and make the whole process longer and harder.

The fifth mistake is not checking the sow often enough in the last days. Farmers get comfortable. They look once in the morning and once at night, and that is exactly the gap in which things go wrong.

The sixth mistake is interfering too early. I have seen new farmers put a hand into a sow because she was restless and lying down, when she was still hours from the first piglet. Handling a sow unnecessarily can bring infection and stress. Wait for the signs of real labour.

The seventh mistake is not knowing what normal looks like, so that real trouble goes unnoticed. If you do not know how long a farrowing should take, you cannot tell when it has gone wrong.

The Step-by-Step Way I Read a Sow

Step one: know the date and move her early. About a week before her due date, I move the sow into a clean, disinfected farrowing pen. The pen should be dry, warm, free of draughts, and quiet. I wash the sow if she is dirty, and I check her for external parasites before she goes in, as the vet advises. I leave her to settle for several days.

Step two: watch the udder. In the last two weeks, the udder gradually swells and fills as the sow approaches farrowing. Over the last few days it becomes fuller, firmer, and warmer, and the teats stand out and look shiny and engorged. The glands lower down the belly, and the teats along the whole line start to look full. Gilts in particular can bag up early, so I do not panic when I see it. I just start watching more closely.

Step three: check the milk. This is my most trusted sign. About a day before farrowing, sometimes less, I gently squeeze a front teat and check for milk. In the final hours the teats usually give milk quite freely. Watery or clear fluid early on can change to a thicker, whiter, milky secretion nearer the time. If I can easily squeeze out milk from several teats, I know I am within about a day, and I begin checking her much more often. I keep my hands clean and my checks gentle so I do not irritate the udder.

Step four: look at the vulva. In the last days, the vulva swells, enlarges, and becomes reddened. Close to farrowing, there may be a small amount of clear or slightly cloudy mucus. This swelling is a good extra sign, but it varies from sow to sow, and some show very little.

Step five: look at her belly and flanks. Near the end, the belly seems to drop and the area beside the tail head, around the pelvis, looks hollow and relaxed as the muscles and ligaments loosen. Her whole shape changes and she looks lower and heavier.

Step six: watch her behaviour. This is where experience pays. In the day or so before, the sow usually becomes restless. She may get up and lie down repeatedly, push at the pen, root at the floor, and refuse to settle. Her appetite drops, and in the last hours she may stop eating entirely, so I take note of a sow that refuses her feed after eating well all week. Her breathing rate goes up, and she may breathe faster even when she is lying still. She may pass small amounts of dung often, and some sows seem to bite at bars or paw at the bedding.

Step seven: look for nesting. Sows have a strong natural urge to build a nest before they farrow. If your sow has been given a little clean straw, dry grass, or other suitable bedding, she will paw it into a heap, carry it around in her mouth, and arrange it. This usually becomes active within about a day before farrowing, and it is often the first thing I notice. If you keep a sow on a crate with a slatted floor and no bedding, she may still go through the motions of pawing and rooting. Do not provide anything that could trap or injure piglets, and keep bedding clean and dry so it does not harbour disease.

Step eight: recognise the last hours. When the sow lies on her side, breathes in slow, deep, effortful breaths, her tail twitches or flicks, and she seems to concentrate, you are close. Some sows pass a blood-tinged fluid or a bit of mucus just before the first piglet. Often, a first piglet follows within a short time, though it can take longer. The usual picture is a quiet sow lying on her side, with piglets arriving at intervals that can range from a few minutes to around half an hour. A whole litter often takes a few hours.

Step nine: have everything ready before she starts. I keep clean towels, a dry heat source for the piglets such as a heat lamp or warm corner, a clean bucket of warm water, iodine or another approved disinfectant for navels, string or clean scissors, gloves, and the phone number of my vet written on the wall. I also keep a torch, because farrowing so often happens at night. I set all of this up before the sow shows her first strong sign, not after.

Step ten: stay near, but stay quiet. Once I see the strong signs, I stay close enough to hear and see everything, without crowding her or making noise. I check on her frequently, and I stay out of her way unless something goes wrong. A calm sow with a calm stockman usually farrows without trouble.

Warning Signs That Something Is Wrong

Knowing when a sow is ready is only half the job. You also need to know when a normal farrowing has turned into an emergency.

If a sow shows strong signs of labour, with straining and deep effort, but no piglet comes out after a long period, something is probably blocking the way. If she stops pushing for an extended time part-way through the litter, while piglets are clearly still inside, she may be tired or stuck. If a piglet is half out and stuck, if she is bleeding heavily, if she has a foul-smelling discharge, if she seems in great pain, or if she collapses or breathes with difficulty, call a vet immediately. Do not wait for morning. Many farmers put a hand in to help, and some situations genuinely need it, but the wrong technique can tear the sow or introduce infection, so ask your vet to teach you in person on a quiet day, not in the middle of a crisis.

Also watch for a sow that is overdue by a few days with no signs at all. That is not always a problem, but a call to the vet is sensible rather than waiting and hoping. And watch for a sow that has a high temperature, refuses water, or stays off her feed after farrowing, which can be signs of infection or milk problems.

What I Would Do Differently If I Were Starting Today

I would record every service date from day one, not trust my memory. I would move every sow into her farrowing pen early, and I would stop worrying about the cost of the extra days. I would build a simple routine of checking udders and milk twice a day in the last week, not just looking from a distance. I would learn from a vet or an experienced stockman how to assist a difficult farrowing before I ever needed to. I would put a notebook by the pen to record start time, interval between piglets, numbers born alive and dead, and anything unusual, because patterns across sows teach you a great deal. And I would never again go to bed with a sow showing nesting behaviour and an udder full of milk.

Frequently Asked Questions

How many days before farrowing does a sow show signs?
The earliest signs, like a swelling udder and vulva, begin one to two weeks before. Nesting and restlessness usually start within a day. Milk that you can squeeze easily means farrowing is usually within about a day or less. Individual sows vary a lot, so treat these as a guide.

How long does a sow take to farrow?
Most sows farrow in a few hours, with piglets arriving every so often rather than all at once. Gilts and older sows may take longer. If a sow strains hard for a long time with nothing happening, or stops mid-litter with piglets still to come, ask a vet for help.

What if I do not know when my sow was served?
Then you have to rely on physical signs, so check the udder, vulva, and behaviour much more often in the weeks when she might be due. Gently check for milk daily once the udder is full. A vet can also help estimate her due date, and keeping better records from now on will save you a lot of stress next time.

Can a sow farrow without any signs?
Most show something, but some sows, especially gilts and very quiet ones, show very little. That is why a good calendar and regular checks are important, and why you should never rely on one sign alone.

Should I help the sow during farrowing?
Usually, no. Most sows farrow without help, and unnecessary interference can cause harm. Stay close, keep things calm, dry and warm the piglets as they arrive, and call a vet if there is a long gap with signs of straining, a stuck piglet, or heavy bleeding.

One Thing to Remember

The calendar tells you when to start watching, the udder tells you when to stay close, and the sow herself tells you when to be ready. Never go to bed on a sow that is building a nest and giving milk.