 Farmers can use the number of teeth in the mouth of sheep and goats to estimate the age of the animal. This is a useful technique when purchasing animals and can assist with record keeping. Goats and sheep only have front teeth on the bottom jaw and are called incisor teeth. There are two stages of teeth, baby or juvenile teeth which erupt during the first month with one pair of teeth for each week. At the end of the first four weeks or month after birth, the young kid or lamb should have four pairs of baby incisors. The video is demonstrating a three week old lamb, one, two, three baby or juvenile teeth that are small in size. As the animal grows older and approaches one to one and a half years old, they will lose the baby tooth in the middle of the incisors and this is replaced by an adult pair of incisors. One pair of adult teeth equal to one to one and a half years old. As the animal turns to two, two and a half years old, they will lose the second pair of baby incisors which again will be replaced by adult incisors. A two year old will have two pairs of adult incisors, one, two adult incisors. A three year old will have one, two, three pairs of adult incisors. A four year old will have one, two, three, four pairs of adult incisors. After four years old and all the adult incisors are in place, the teeth will begin to show where as the animal ages past five to six years old. Some teeth may even begin to shake. After eight years of age and depending on the forage or grasses that the goat consumes, some goats may lose all their teeth. A sheep or goat with no teeth suggests that the animal has significant age.