I would just mention again the high chance of mastitis if you leave 3 on a ewe. It is such a temptation when you see the ewe has plenty of milk and is coping well, and especially when you can just top the lambs up with a bottle and not have to deal with a solitary pet lamb. But in no time at all the sweet gentle little lambs turn into voracious feeders and the ewe, with the best of feeding, just cannot cope. I have spoilt many a good ewe by convincing myself "this is a good mother, plenty of milk, she can manage." The poor animal, being constantly butted for milk develops mastitis and has to be culled. I would say, the chances of a ewe left with 3 lambs developing mastitis is about 80%. I have had it work; but the triplets never grew as well as a good set of twins, so now I would just keep 2 on and either foster the third, bottle it completely, or sell to someone else. (If the latter, you obviously keep the 2 biggest and sell the smallest!)
This.
Sadly, I suspect it is something each of us has to learn for ourselves
Having said which, the last two years we have managed to keep four lots of triplets without having any full-on pets, but keeping the families together in the field. Sometimes that doesn’t work; sometimes the mother stops the lambs coming for the bottle.
In three of the four cases, it’s started with topping up all three lambs in the family and pretty soon settles down to one lamb gets most of its feed from us, one gets top-ups from us when it’s hungry, and the third lamb soon stops coming to us and is it’s mother’s favourite.
If the mothers had prevented us feeding any, or if the third lamb had been seen to be bullying the mother for milk at any time, I would have taken the third lamb off.
Our Lessa (Shetland x Blue-faced Leicester, very milky) just keeps having three, and when it was Shetland cross lambs, a lovely spring and a good (not too dry) summer, she managed just fine with no help except always being on the best grass and having grass pellets if she wanted. Last year it was Romney cross lambs and a cold spring, and she needed a bit more help early on. She wasn’t too keen on us topping up her lambs but we kept the family handy until the lambs knew all about the bottle and would come running when called, no matter what Mum said! When we then had a long drought, we were soooo glad we’d got two of her lambs trained to come for a bottle!