Hello, we have two nigerian dwarfs that just kidded two weeks ago. I have begun to milk them once in the morning after they have been separated from their kids through the night. The milk has an almost sour taste to it. Could it be that the colostrum is not fully gone (although it is foaming when I milk)? Or could it be some other reason? I have a Nubian that I had milked earlier this year, we got her way after she had freshened. Her milk was amazingly sweet! I want that same sweet milk back and was expecting that from my dwarfs. Any suggestions?