People used to put a silver dollar in their milk jugs to prevent spoilage. I guess the effect is similar to colloidal silver. I wonder if you could make raw milk safer than pasteurized milk by processing it through a high surface area silver coated system. I suspect the effect is not so much from dissolving silver as from contact between the silver and the bacteria. If so, negligible amounts of silver would be added to the milk and a milk product could be safe without being pasteurized. Or silver plated reusable containers could be used. It is possible that raw milk could be done that would keep longer than pasteurized milk.
The preliminary testing should be quite simple. Get some pure silver wire and make a pump through sieve to process the milk. Process it for different lengths of time, then see how long it takes to spoil. Also, perhaps more important would be some highly precise testing to determine how much silver turns up in the milk. I doubt you would see enough to cause Argyria even in a lifetime of use, but this could be a limiting factor.
Before marketing, more extensive testing would naturally have to be done, for example with specific pathogens, but it wouldn't be too expensive to do the proof of concept testing before seeking funding.
Colloidal silver is extremely broad spectrum, so I suspect it would be effective. Harmful bacteria are selectively killed because they are positively charged on their outer membranes. Silver kills them without effecting the body. For this reason, beneficial bacteria might not be effected the same way.
I would prefer milk to be unprocessed in any way, but think it would be wonderful to trump the asshole zealots who want to heat everything and provide a milk to the general public that would be even safer than pasteurized and RAW!
TruthHunter