How to Know When a Cow Is Ready to Give Birth
How to Know When a Cow Is Ready to Give Birth
I once went to bed on a cold night certain that my heifer was at least a week away from calving. At dawn I found her standing over a calf that was already up and sucking, and I felt something between relief and shame. She had shown me every sign the evening before. I just had not known how to read them.
Here is the direct answer. A cow is getting ready to calve when you see changes in four places: her body (a sunken, relaxed area around the tailhead and a swollen vulva), her udder (tight, full, and often waxy at the teat ends), her behaviour (restless, isolating herself, getting up and lying down), and her temperature (a drop of about one degree Celsius in the last day or so before birth). Real labour usually starts when she is straining visibly, and a healthy calf should follow within a couple of hours of that. If it does not, you call for help.
Let me walk you through what to watch, day by day, and when to step in.
What most farmers get wrong
The first mistake is counting on the date alone. A cow’s pregnancy lasts roughly 280 days, but healthy calvings happen days before or after that figure, and heifers, different breeds, and twin pregnancies can run differently. The date tells you when to start watching. It does not tell you when she will deliver.
The second mistake is watching only the udder. Some cows bag up weeks before calving, and some heifers bag up late. Treat the udder as one clue among several, not as a clock.
The third mistake is leaving her in a big, rough pasture with no one checking. A cow that calves alone in thick bush, mud, or a crowded yard faces more danger from cold, predators, and trampling, and you may not find out about a problem until it is too late.
The fourth mistake is rushing in. People see a cow lying down and straining and jump to pull the calf. Most cows calve fine without help, and unnecessary pulling injures both cow and calf. The skill is knowing when to wait and when to act.
Three to four weeks before: the early signs
You will not see everything dramatic yet, but small things start to appear. The udder begins to fill and the cow looks heavier and more rounded in the belly. Heifers often develop an udder first, sometimes a month before calving, while older cows may bag up closer to the date.
Pay attention to her feed. In the last weeks, a pregnant cow often needs slightly better feeding to prepare for calving and milk production, but she should not be fat. Overfat cows are more likely to have difficult births. Your vet or livestock officer can advise on the right ration for this stage, called the close-up or transition period.
This is also the time to move her. Put her in a clean, dry, shaded paddock or pen close to the house, where you can see her easily and she can move about freely. I prefer a grassy paddock over a small, muddy pen, because the cleaner the space, the lower the infection risk.
One to two weeks before: the body changes
Now the signs become clearer. The udder gets tight and shiny, and the teats fill out. The vulva starts to swell and become longer and softer. The muscles and ligaments on both sides of the tailhead, the area at the base of the tail where it meets the rump, begin to relax. You will see the area look sunken and loose, and the tail head may stick up and look more prominent. If you press with your fingers on either side of the tail base, the ligaments feel soft and slack instead of firm like cord.
A thick, stringy, clear mucus may start to hang from the vulva. This is normal. It is the plug that has been sealing the cervix, and seeing it means the body is preparing for birth.
Twenty-four to forty-eight hours before: the final signs
Now things speed up. The udder is full and often so tight that it looks like it will burst, and many cows develop waxy beads or a sticky, waxy substance at the ends of the teats, which is a good sign that colostrum has formed. Do not rely on it alone, because cows differ and some leak early.
The vulva is now very swollen and relaxed. The tailhead ligaments are almost completely loose. The cow’s belly may look as if it has dropped and the calf has moved into position.
The cow’s behaviour changes. She often walks off from the herd, looks for a quiet corner, paws the ground, swishes her tail, or keeps lying down and standing up. She may stop eating, look uncomfortable, or lift her tail. Some cows become nervous and some cows become unusually calm. Learn how your own animals behave, because this varies.
Take her temperature. A cow’s normal temperature is about 38.5 degrees Celsius. Roughly twelve to twenty-four hours before calving, it often drops by about one degree, sometimes a little more. Take it twice a day with a clean thermometer and write the readings down. A drop does not guarantee she will calve right away, but together with the other signs, it tells you to be ready. Remember that rectal thermometers should be handled carefully and cleaned between animals.
When labour starts
Stage one of labour is the quiet stage. The cow is restless, may have mild contractions, and is preparing the birth canal. This can last from a few hours up to half a day or more, longer in heifers. You will see her get up and down and look uneasy. Leave her alone as much as you can. Watching from a distance is best, because interference can stress her and slow things down.
Stage two begins when the water bag appears and she starts to strain visibly. The calf’s front feet should come first, soles pointing down, followed by the nose resting on top of the legs, like a diver. This is the normal position. Once she is really pushing, a healthy cow often delivers within about an hour or two. Heifers may take a little longer.
Stage three is the afterbirth, which should come out within hours, usually within about twelve hours after birth. Do not pull on it. If it is still hanging after twenty-four hours, call the vet, since retained afterbirth can lead to infection.
When to wait and when to help
Most births are normal, and the best thing you can do is watch quietly and stay out of the way. But there are clear moments when you should get help immediately.
Call a vet or an experienced livestock officer if she has been straining hard for more than an hour with no progress, if you see only one foot, or you see feet with the soles pointing up (which can mean the calf is backwards), or a head with no feet, or a tail, or anything that does not look like the normal diver position. Call for help too if the water bag has broken and nothing has happened in a couple of hours, if the calf appears stuck at the hips, if the cow seems exhausted or collapses, or if there is heavy bleeding or a foul smell.
I will be honest. I do not give step-by-step pulling instructions in an article, because a wrong pull can kill the calf and tear the cow. If you have been shown how by a vet and have the right clean equipment, you will know the basics. Otherwise, pick up the phone early. A vet call is cheap compared with losing a cow. Keep a vet’s number saved in your phone before calving season, not after trouble begins.
After the calf arrives
Make sure the calf is breathing. Clear the nose and mouth of mucus if needed, and let the cow lick the calf, because licking stimulates breathing and bonds the pair. Dip the navel in an antiseptic solution as your vet advises, to prevent infection.
The calf must receive colostrum, the first milk, within the first few hours of life. Ideally, the calf is standing and suckling within one to two hours. Colostrum carries the antibodies that protect the calf from disease, and a calf that misses it is at serious risk. If the calf is too weak to suck, ask a vet how to help it, and make sure it gets colostrum by one means or another.
Watch the cow too. Check that she is eating, drinking, passing the afterbirth, and showing no signs of fever or weakness. Milk fever, a shortage of calcium that can hit dairy cows soon after calving, shows up as weakness, trembling, and difficulty standing. It needs a vet quickly.
Warning signs that something is wrong
I watch for a cow that goes past her due date by a lot with no signs, a cow showing signs of labour for many hours with no progress, a dark or foul-smelling discharge, a cow that strains but nothing appears, a calf that is not breathing or is too weak to stand, and a cow that seems very weak, shaky, or dull after calving. Any of these means call for help right away.
What I would do differently if I started today
I would record every service or breeding date so I always knew the expected calving window. I lost sleep and a calf once because I guessed.
I would check my cows at fixed times, such as late evening, midnight, and early morning, in the last week, instead of hoping to notice by chance.
I would prepare a calving pen or paddock ahead of time, with clean ground and water, and keep a bucket, clean towels, antiseptic, a torch, and a thermometer ready.
And I would arrange a vet contact before I needed one.
Frequently asked questions
How long is a cow pregnant?
About 280 days on average, which is a little over nine months. Individual cows can calve a week or two earlier or later, and breed and calf sex can shift the timing a little.
How many hours before calving does a cow bag up?
It varies a lot. Heifers often bag up weeks ahead, and older cows may only fill in the final days. The udder alone is not a reliable clock.
What are the first signs of labour in a cow?
Restlessness, separating from the herd, tail lifting, repeatedly lying down and standing up, and sometimes a loss of appetite. Mucus discharge and a very relaxed tailhead usually come first.
How long should a cow be in labour before I worry?
If she is straining hard for around an hour with no calf appearing, or if you see anything abnormal in the position, get help. Do not wait for hours hoping it will fix itself.
Should I help every cow calve?
No. Most cows deliver on their own, and interference can cause harm. Watch from a distance and step in only when there are clear signs of trouble.
The advice worth bookmarking
A calving cow wants peace, preparation, and a phone number you saved yesterday, so watch her closely, leave her alone when things go right, and call for help the moment they do not.







