It would be slightly more believable if they got the amount that a typical adult bovine drinks per day right.
20 to 30 gallons per day is rather more like it in the summer. 10 gal/day might... MIGHT be a winter expectation. Might. In the Great Basin, they drink more, because even in winter, the humidity is low.
Exactly. I question the science behind it unless it is if they are so dehydrated then they drink uncontrollably and staturate to quickly and die from water intoxication.