Goats milk is closer in make-up to human milk than cows milk is. I think it's to do with the casein (milk protein)? Someone please correct me if I'm wrong.
When I had to use a substitute milk for Samantha I used powdered goats milk from the healthcare shop, not the Karicare one - I don't remember the name though. You can also get hold of fresh goats milk in a lot of healthcare shops now, and dilute it with boiling water - 2/3 milk to 1/3 water will bring it to the correct consistency and temperature for babies, I found. One of my friends used this a lot too for her children when she had milk supply problems.

Kerrie