Is it true that cows drink 1800 gallons of water in a lifetime?

Answer 1

That question is unanswerable because it really depends on the cow's bodyweight, the type of cow, and the reproductive, physiological, environmental and seasonal changes she had to go through. It also depends on how long a particular cow lives for, where she lives, what she has eaten, etc. All of these things affect her water intake.

One can only make a general assumption to how much a cow drinks per day, much less per year, so it's really a very vague assumption that this estimation could or could not be true.

One thing that should be known is that DAIRY cows tend to drink a lot more than beef cows. If you were referring to your average Holstein, I couldn't see why this number wouldn't be incorrect; as a matter of fact it could even be an underestimate.