What are the signs of bovine parturition?

A cow or heifer that is about to give birth or undergo parturition or is going into labour will initially show signs including her udder swelling with colostrum, her vulva engorging with blood making it look a bit swollen, her sides sinking in front of her thurls and there may be some mucous coming out of her vulva. She'll get fidgety and look for a place to calve. When her udder is full, she's about 3-7 days from calving, although some cows or heifers won't show any freshening until the day they are about to calve, and others may have a full bag for weeks before she drops a calf. When her sides sink in, she's around 1-3 days from calving. When there is discharge from her vulva being the clear, non-sticky, stringy stuff, she's less than a day away from calving. However if the discharge is more sticky and thick, this is just the mucus plug being removed, which occurs about a week before calving. When you see that water bag, she's in labor and it's just a matter of minutes before the feet and head of the calf start to show.

During the birthing process, she will be pacing around, acting very fidgety, unable to stay in one position for long. She will be holding her tail out behind her, like she would if she were just bred. She often will find a place away from the herd to settle down to give birth, and still tries to lay down and get up, then lay down again only to get up. She may be pacing around in a circle, stopping to strain every so often (you can tell by watching the stomach muscles contract on her belly and she stops breathing to strain). There will be clear and thick mucus discharge from her vulva, soon followed by a water sac (yellowish in colour). Soon after the water sac appears you should be able to see feet sticking out, and these feet should have the bottoms pointing downwards, indicating that the calf is coming front first. You should also see that BOTH feet are coming out; if there's just one you might want to consider getting the cow in a head-gate for you to go in and bring the leg up or get the vet to do it. Soon after the feet and the first part of the legs show the nose, muzzle and head soon follow, then the shoulders. After the shoulders the rest pop out easily, however trouble can also come if the hips get locked in the cow's pelvis. Don't hesitate to help her out then either if she doesn't progress to dropping the rest of the calf. But if the hips don't get locked, before you know it you'll have a new baby calf on the ground. Congrats!