Recently I picked up my sheep from a breeder who has a flock of 200 American Barbados sheep. Although my sheep is a Suffolk ewe, a woolie sheep with a black face,  I like the breeder and I liked his sheep, and so I decided to cross them with the Suffolk even though the Barbados are tiny little things with hair instead of wool For the breeder, his sheep are a means of making a living, but I'm in the sheep business just for fun with a tiny flock to enjoy.
Among his sheep, I noticed a ewe who was crippled.  Upon closer observation, I noticed her ear was torn.  The breeder told me she was blind, and when she strayed away from the flock, a coyote got her.  He agreed to let me take her home.
Whether she and the Suffolk were friends before or they became that way from riding together in the pickup for the 100-mile trip home, I don't know.  But the little Barbados mainly ignores the other sheep that are like herself, and shadows the Suffolk who is twice her size.  It's as if she finds safety trailing a large animal.  The Suffolk, named Beauty by the way, seems fine with the arrangement.
As I write this,. the sun is shining in their snowy pen, and they are lying down together ,soaking up the rays.  When Beauty gets up to go into the shed, she'll have the little one right beside her. 
No one told anyone to look after the less-than-whole little sheep.  No agency had a thing to do with them.  That's one of the appealing thing about  animals..  They know how to take care of their own. Although Beauty was named in jest, the big sheep who towers above the rest was given a proper name after all..