Wyverns lose 1 good point per 10 seconds, and 360 points per hour. So 1 wyvern milk will sustain a wyvern for 3.33 hours due to it's 1200 food points. If it's a low level, it might not have 1200 points and have to be force fed milk to avoid starvation. But once you feed it milk and it goes up 1200, you can safely walk away for 3.33 hours and return back to knock out a wyvern and feed it after. If you want to imprint, that's a different story. (The same wyvern can be knocked out for 5 milk every 1 hour). Preserving bin + preserving salts for milk = little over 2 hour spoil time. Good luck getting a wyvern! P.S. make a wyvern trap. It's the best method for getting milk. :)

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