On lot 6007 on smp3 i made a derpy animal/sheep farm and anyone is free to use it but please breed the derpy animals. I was going to make it really cool but something else popped up and i dont think i will have time to finish the part that i didn't finish. also there are about 160 sheep i think. Here are some pictures.
I have a suggestion. Place water around the edges flowing inwards 3 blocks and then hitting a hole., This stops them from escaping.