New experience:  we pulled a calf.  Not too difficult, and I wonder if we’d given her a couple more hours would she have done it herself — probably — but it was a big bull calf, laid right but with his shoulders pretty tight in the passageway, and a little traction on first one leg, then the other, had him out in just a few minutes.  Dystocia, I think it’s called, and a lot harder to finesse in human births than with calves, which lead with their front feet.