An interesting anatomical feature of some vegetarian animals is that they don’t have upper front teeth. Goats still have 32 teeth just like we do — some of usteeth3 — but they’re placed differently. We use our front teeth for biting and the back ones for chewing; whereas cattle and goats have 24 molars and premolars top and bottom to chew with, but their 8 incisors are all attached to the front of the lower jaw. On the top a goat has what’s called a ‘dental pad’

Misty eating windflowers

Misty eating windflowers

it’s a patch of tough skin covering the gums.

Goats eat leaves and tree bark and grass. misty31While a cow uses her terrifically long tongue to wrap around a clump of grass and her lower incisors cut it off, goats don’t have long tongues and they seem to simply bite the leaves against the dental pad. (Inci-dental-ly, in the picture below you can see that goats’ eyes have rectangular pupils.)misty2They swallow their food mostly unchewed. misty4This behaviour goes back to their wild ancestors’ habit of dashing out from under cover to eat and run back before getting mugged by the neighbourhood meat-eaters.  A goat’s stomach has four compartments. The food enters the first, called the rumen, for a short time and then it is pushed back up through the esophagus and into the mouth, where it is chewed and re-chewed. This is cud chewing, and it goes on for  hours. misty5If you see a goat or cow apparently chewing gum, it is more likely that it actually has cud in its mouth.  Cud chewing decreases the particle size of the stalks and leaves, making the chopping function of front teeth unnecessary.

Goats aren’t the only animals with a dental pad instead of upper incisor teeth; most ruminants — sheep, cows, deer and camels — are the same. Horses, like us, are ‘monogastrics’, they have one stomach. Horses don’t ruminate, and like many of us they have upper front teeth.  It’s possible to tell what kind of stomach an animal has by looking at its teeth. No upper incisors means ruminant.  Cows and goats can lose their teeth after 10 years, a condition known as peg teeth. Since their teeth wear down at a known rate (cows chew at a rate of about fifty-thousand jaw movements a day), tooth wear can be used to deduce age.misty6

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