Whew! I thought you were talking about feeding cow bodies to other livestock, but you're talking about
dairy products. I am not an expert, but I have read other people recount their experiences with fermenting dairy, and I did keep a kefir culture going for a few months. Walter Jeffries raises hogs on whey and is able to keep a yogurtish culture going in big tanks, outside in Vermont. Another women told of dumping extra goat dairy into a ? 5 gallon bucket that went to her hens.
Anyway, I would encourage you to look into kefir.
I have a feeling that fresh clean raw milk is more likely to ferment than to spoil, but I don't have hard data to back up that intuition. I would encourage you to try, and trust your senses as to whether the ferment/cheese you've made is food. When it comes to hens, in my 12 years of
experience of giving them our scraps, including spoiled food, they are very good at figuring out what to eat and what to leave.
I would also recommend checking out Walters excellent blog at sugarmtnfarm.com and searching for "whey" and "dairy."