sam2- thanks for engaging in this stimulating dialogue.As far as your last post,concerning milk, I must disagree with you. Once the milk is considered kosher ,it remains kosher forever. Hence, as most cows asre considered healthy, the milk we get from them is kosher and nothing can make them ‘treifa” (you cannot even apply “chozer veniur”, as the milk is considered kosher).
SO,all of your many bottles are kosher regardless whether there may be more than 1.6% of milk from a treifa animal. A chazokoh doesn’t disappear. As a matter of fact, you don’t even know whether the milk comes from a herd that does not have any treifas.I am saying that you don’t need the ta’am of bittul ,unless you know for sure that there is some milk from treifas.
The problem with cows with DA is that we KNOW that in this herd there are some cows who have it and therefore we may not be able to say that there is a rov or a chazokoh.
Anyway- i still don’t see how you this escapes lach belach. I’ll try to answer your other comments in another post.