Goats are known for being cute, intelligent and amazing climbers, but they are also known for their ability to chew and digest large amounts of grass and other plants. In fact, they are so good at it many people are now using them to mow their lawns. You can even rent a goat to come gobble up those pesky weeds!
Goats are ruminants, which means they have 4 chambers in their stomachs which help them break down plant matter into energy. The largest of these chambers is called a “rumen,” where the digestion of the goat’s meal begins, and to help in this digestive process, goats will cough up cud (a ball of plant matter from the rumen) and continue chewing on it before swallowing again. Yummy! However, goats eat a large amount of gritty sand and dirt with each mouthful of grass, and this made scientists wonder why their teeth never appeared to wear down. You would think spending hours a day chewing on regurgitated grit would be bad for your teeth, right?
Well, a team of researchers decided to solve this mystery by feeding groups of goats diets with different amounts of grit for 6 months. At the end of the 6 months they analyzed the goats’ stomach contents and found something surprising! When the goats swallowed a dirty mouthful of grass, the plant matter stayed in that large stomach chamber, the rumen, while the dirt and sand immediately passed into the lower stomach chambers. The sand and dirt would then be pooped out without ever being regurgitated for chewing. This showed that the rumen serves as a sort of washing station, cleaning the plants before they are regurgitated as cud, and therefore protecting the goat’s chompers! And the researchers think that this clever design is not just used by goats, it may also explain why other ruminants, like cows and giraffes, have healthy teeth despite years of intense chewing.
Want to learn more? Visit https://www.sciencemag.org/news/2019/06/why-dirt-eating-goats-never-need-visit-dentist
July 12, 2019