Fact: Drooling Cows

Fact: Cows produce tons of saliva. Ok, not literal tons but lots and lots of the stuff. See, cows happen to like to eat grass. The problem with eating grass is the amount of cellulose in it. Different animals that use cellulose as a source of food have different mechanisms for dealing with digesting the stuff and cows, as you may know, deal with it by being ruminants. First, they ruminate, or chew their cud. Basically, you chew your food once, swallow it, let it sit in your rumen for a few hours, and bring it back up to chew again. Second, they have that rumen. The rumen is essentially a fermentation vat where microorganisms help break down cellulose so it's possible for the cows to digest further. The byproducts of this fermentation are carbon dioxide and methane which the cows let out by burping (technical term=eructation. You can now sound super smart when you ask your little brother to stop eructing at the dinner table). But we aren't worried about the byproducts. Those aren't helping the cow get energy and they aren't why they need so much saliva. The fermentation products are mostly acetic acid, propionic acid, and butyric acid. Notice something there? Acid. Well, "copious amounts of saliva" (as stated in my Animal Physiology textbook by Knut Schmidt-Nielsen) are produced by ruminants to help buffer all these acids in the rumen. In a smaller ruminant, like a sheep or goat, the amount of saliva produced per day has been estimated to be around 6-16 liters. In a cow, the estimated amount of saliva produced per day is around 100-190 liters. That's 26-50 gallons of saliva per day!