Basically, what you specifically need is a recipe for an
emulsified body butter (which is much different and involves more work to make than an anhydrous body butter), for anytime you add water or something with water in it- like milk- to a body butter, you'll need an emulsifier to keep the water and oil together in suspension. And you'll definitely need a good preservative, too. And you'll need to follow proper lotion-making procedures such as sanitizing and heating/holding, etc.... I would narrow your search field down to read 'emulsified body butter'. You're sure to get more hits that way.
I've never added milk to my lotions or emulsified butters before, but I know of a few that do. One of them from another forum (who I find to be trustworthy) never uses more than 10% goat milk in her recipe (along with a good preservative) and another one from here never goes over 12%.
I've always shied away from using milk myself for the same reason judymoody mentioned- it's hard to preserve. Having said that, though, I bought a kit from LotionCrafters- this one:
http://www.lotioncrafter.com/caprabella ... m-kit.html that is made with goat milk powder, but I haven't made it yet. I bought it because I find Jen at LotionCrafters to be very knowlegable and trustworthy- and it only has 1.1% goat milk powder in the formula- a good conservative amount for a scaredy-cat like me. And she uses a very good preservative (phenonip)
and a preservative booster in it (tetrasodium EDTA). Jen also has the recipe for it on the LotionCrafter's site.
Also, the link that judymoody gave you- Swiftcraftymonkey's site- is awesome. I highly recommend it. Everything you ever wanted to know about lotions/butters/conditioners, etc...but were afraid to ask, is on that site. It's a virtual treasure trove of trustworthy info.
For what it's worth, here is a good, fairly recent thread from right here on the subject of making an emulsified body butter:
http://www.soapmakingforum.com/forum/vi ... t=template
and here are some threads referring to the use of goat milk in lotions:
http://www.soapmakingforum.com/forum/vi ... ilk+lotion
http://www.soapmakingforum.com/forum/vi ... ilk+lotion
http://www.soapmakingforum.com/forum/vi ... ilk+lotion
http://www.soapmakingforum.com/forum/vi ... ilk+lotion
IrishLass