TLDR: milk is produced in closed system now, meaning dust from the barn doesn't get in it. They added 1 part per thousand of hay dust to the milk, and all the holes came back

Thank you for the summary.

YouTube links are a terrible way to transmit information.

Indeed. That's why this tool comes so handy (already featured in hn), https://www.videogist.co/videos/how-they-saved-the-holes-in-...

1cc of hay dust per liter of milk is actually a lot of hay dust. does the hay need to be from the barn, are we talking barn dust here?

That is a lot. What they actually said was 1 mg of hay dust per 1000 L. They didn't elaborate on how they sourced their hay.

That’s 1 ppm. Much more reasonable!