The health of your sheep is paramount.
De-worming-Lambs have to be on a de-worming schedule for their first year maybe less depending on whether you have quality pasture. Although I have never had a lamb die from an infestation it is very possible if you aren't diligent in prevention. On the other hand I have adult sheep that have not been wormed in 7 years. This is due to the fact that I do not over graze my sheep. Over grazing exposes the ground where the parasites live and there is a far greater chance of infestation when there isn't enough grazing available. Initially we were told to worm everyone every 3 months no matter what. Well, I couldn't feel good about giving my sheep all of those chemicals for no reason. You just have to be observant and monitor them daily. Check the color of the lower eye lids and energy levels. I have never lost a sheep to parasites. I de-worm adults on an as needed basis and I decided to do this long ago. I asked my vet about it and he agreed.
Ear tags, tail docking and castration-What I have learned, believe me I am no expert, but for me is has proved best to do all of these things with-in the first week providing you have strong healthy lambs. The longer you wait the more stress these procedures may invoke. Sometimes if I have a twin who is smaller and a bit weaker I wait until it doubles its weight. I do not give CD&T shots. I use a tetanus anti-toxin. I don't give my sheep the opportunity to overeat.
Weighing lambs-Personally I feel more comfortable weighing my newborns daily to make sure they are gaining. It is some trouble, but well worth the peace of mind it gives me.
Feed-I won't feed my sheep corn, I don't think it is healthy for them. I give them non-GMO oats mixed with sheep and alfalfa pellets, but only occasionally. I don't feed them unless I want them to move into a building or change fields and then it is only a handful each. They get fat on grass, they don't need it unless you don't have adequate pasture. Grazing in the vineyard is limited because we are on a spraying schedule. Early spring is when they are allowed in before spraying occurs. We only let them in to eat the new growth that has not been in contact with spray long after the recommended length of time required as listed by the chemical company. In other words, we feel like a good rule of thumb is, if we won't even eat a food that has ingredients we can't pronounce or can't immediately identify, we certainly won't feed anything to the sheep we aren't willing to eat ourselves.
Hoof trimming-Depending on their environment sheep may need to have their hooves trimmed from 2-4 times a year. I live in an area that has no rocks so there is nothing for the sheep to wear their hooves off on. My sheep are trimmed 4 times a year.
Plant toxicity-We have learned the hard way what can happen if a farmer is uneducated about the dangers of some common trees and plants. We lost two of our best ewes to wild cherry trees. Some say sheep won't eat the bark off a tree. I don't just disagree, I know for a fact that they love the bark off of apple, cedar and some nut trees when the spring sap is flowing. Spring 2016 we opened up a new pasture thinking we were doing the sheep a favor. The first set of lambs were 8 week old when their mother was just staring into space. The next morning she wouldn't get up, she seemed stiff, in a couple of hours she was gone. Three days later my best ewe Cynthiana did the same thing. I wormed her (just in case, although she showed no signs of parasites), I gave her penicillin, I called the vet and she died before I got her there. I did have an autopsy performed along with a fecal and some other tests, he was convinced it was plant toxicity. When I got home I looked all over the field and in the woods. The spring leaves had just barely started to come out, I had been asked by my vet if there was a storm that caused any cherry limbs to break and wilt because that is the danger from those trees. That was not the case. The bark off of every wild cherry sapling was completely stripped off within reach. Every single wild cherry tree in the woods!! We had a third ewe acting sick the same day, I immediately moved her and her lambs out. Thank goodness she made a full recovery and has had healthy twins since. Needless to say we pulled 32 wild cherry trees up by the roots and burned them. We continue to monitor for new saplings and have never had another issue due to toxic plants or trees.
I am out of time, more on health issues and unusual circumstances we have encountered later. Like I say, we are no experts, but every year we learn a new thing or two!