I just saw your pm this morning. For some reason, the pop up window didn't come up and my notification didn't highlight.
I'm sure it's Becky's fault. Most things are.
I have never used fresh goats milk, but from what I was told you don't need to water it down, you just use it straight from the carton. The watering down part comes from the canned being concentrated.
A can is 12 ounces (I just checked) and you would normally add another can of water. So I would do 24 ounces of fresh goats milk with 1 teaspoon of baby rice cereal.
The only thing I would be unsure of is the longevity of the milk. With the canned, it's not good for more than 48 hours. So I freeze it as soon as I make it. With fresh milk, I suppose you could freeze it as well, or you could just cut it way back. Maybe due 1/2 cup of milk with 1/8 teaspoon of baby rice cereal and dump it after 48 hours then start with fresh again.
I don't know though, it seems like that would be an awful waste. I think I would go ahead and mix up the 24 ounces with the 1 teaspoon and then freeze it in an ice cube try, taking one ice cube out at a time, thawing it, dumping what you don't use after 48 hours. After a couple weeks you'll end up going through several ice cubes in a 2 day period.