We had a cow ready to calve and thought we would try to take some pictures of her.  This is Strawberry Wine, a 3 yr old cow.  I had her due June 30th.  She calved June 29th
5:45pm Most of our cows calve in the middle of the night. But this year we have had a lot born during the day.  I have been watching her close and earlier in the day I noticed she was wandering off by herself.  Notice her tail sticking out.  Some mucus begins.  I have seen our cows kick their belly, back up and act like they are chasing their tails.
6:15pm She starts laying down and pushing.  She was up and down numerous times.  She would look and me and let out a low moo...Asking for help and telling me to leave. She did this for about 30-45 minutes.  She would stand up and have contractions and it would almost buckle her back legs.
7:00pm She lays down and pushes out the birth sack.  If you look close there is a white line on the sack.  That is the calf's foot.  She pushed and it comes out about 6 more inches and then retracts.  Sometimes the birth sack will break and you can see the feet and nose.  Hers remained intact.  Cows generally have a calf in 1 hr, heifers 2hrs. 
7:35 I felt like I was bothering her and I figured she had some more time so I left her alone.  She moved and was up and down about 6 times before I looked out of the house and seen the calf come out.  I checked.....IT'S A HEIFER. I moved her out of the mucus and cleaned her mouth out a little.  If you stick straw,hay or grass in the nostrils of a new calf it will tickle their nose and they will sneeze or cough.  It helps remove the mucus in the mouth and nose.
7:55pm The calf was lifting her head right away but she is setting up and has even tried to stand a few time now.  Mom is cleaning her up as best she can.  The mother's licking helps get the calf moving and stimulates the calf.  Some cows are very gentle and nudge.  Others are a little agressive, especially if the calf is not moving much.
8:35pm Had to run to the neighbors and when we got back she was up nursing away.  Mom would let her nurse for a minute or two and them walk a few feet and then let her nurse again.  Alot of times mom will lick the calf's rear end while they are nursing to stimulate the calf's bowels.  Got to make sure all systems GO!
40 hrs old. Both mom and little girl are doing great.  Mom can't keep up.  She loves to run.  The rest of the time it is napping in the sun.  It is a lot of fun to watch the calves play in the late evening.  Mom is very attentive.  She doesn't get to far away from the calf, even when it is napping.