I have sheep which I breed for lambs which are sold and raise weaners for the freezer.
The sheep do make a profit, however it really isn't much at all and if you break it down to a weekly wage after you have paid for their yearly costs its maybe £25 a week.
Pigs are different, I find that they cost more for me to buy and raise than their value in meat, but I enjoy having them and enjoy the pork they produce.
I wouldn't class my livestock as pets, as I wouldn't keep an old ewe that was no longer suitable for breeding and I wouldn't keep a pet pig either.
Selling lambs that you have raised - that are destined for the table, or taking pigs for slaughter is never easy and it is always a bit of a sad day. You just have to come to terms with it, the payment for lambs is always needed and having a freezer full of your own produced pork is pretty amazing.