We're just about done calving our heifers, 3 left, and I would say Big Muddy and Kola gave the best advice. Everytime you think you put the right one in the pen, or try to go anywhere for a few hours, when you get back to check them........you were wrong.
I always watch the vulva and watch to see which ones are kind of hanging out on their own. Also the bag is good but not real accurate in my mind depending on the size of bag they have.
Soapweeds advice was real good to. Be careful how you put the chains on, it can really hinder them from getting up real good to get on with life.
We've done alright this year. 25 heifers and only a few mishaps, lost two calves from ????, dead when I got there. Pulled three, but those were mainly on heifers that went over an hour after the water broke, just to get the calf on the ground, and only two have been on the big side, but not bad. Started calving cows a week ago, and we're about 1/4 done on them.