Well calving in the mob is certainly not easy and creates a lot of mental anguish. All things considered however, things are going pretty well. We're a few weeks into calving and have a few hundred calves on the ground. We've treated maybe 20 calves for scours and have lost 3 (only one of which we treated). We've also had 2 calves born dead, one calf stomped down in a ravine, one calf died with what appeared to be bvd, one calf out of a heifer we pulled was dead, and 2 calves that died as the second born in 2 sets of twins. We've been leaving the back fences open so that the cows can go back and get their calves. Some cows go back and regraze and sometimes it's difficult to keep the mob together to move them to the next pasture, but I think that closing that back fence creates problems....calves just won't go to the cows, especially the very young ones. The cow needs to be able to get back to it's calf, and leaving that back fence open seems to be the best way to go.
As an aside, following the advice of Ian Mitchell-Innes, we have begun offering free choice Zinc Sulfate and Zinc Oxide to the cattle in an attempt to reduce incidents of scours. I'll keep you posted on the efficacy we observe.