When might you need to look at a goat’s teeth to estimate its age? Perhaps when selecting breeding stock, slaughter animals, or individuals to cull. It’s a good idea to look at an animal’s teeth before purchase to make sure you are buying the age of animal you want. Teeth should also be monitored regularly to check for treatable problems and make culling decisions based on age and soundness.
All goats only have incisors on their lower jaw; these are the teeth used to judge age. Kids are often born with their first pair of deciduous incisor teeth, also called baby teeth or milk teeth. Subsequent pairs of baby teeth erupt from the center outward, typically one pair per week so the kid has a full set of eight incisors (four pairs) at a month of age. These baby teeth last for the first year of the animal’s life.
The first paired set of permanent or adult teeth start in the center, replacing the baby teeth at about 12 months of age; these animals are sometimes called a “two-toothed goat.” The next adult pair to come in is on each side of the center pair. This happens when animals are about 1.5 to two years old. The third pair of adult teeth is adjacent to the previous pair and erupt when animals are 2.5 to three years old. The last and outermost pair erupt when goats are 3.5 to four years old. Goats with a “full mouth” have all eight adult incisor teeth erupted and in wear and are at least four years old.
As with humans, there is variation on actual tooth-eruption dates for individuals; the ages reported here are estimates. However, as a general rule, a goat with one pair of adult teeth is about one year old, two years old with two pairs of adult teeth, three years old with three pairs of adult teeth, and four years old when all four pairs of adult teeth have erupted.
It’s difficult to age goats over four years old accurately. The variation has to do with the amount of wear on the animal’s teeth, and this is affected by diet and the animal’s environment. As animals age, their teeth spread, look more elongated, and sometimes break or fall out. Animals with missing or broken incisors are called “broken mouthed.” These should be culled from the production herd due to typical poor performance related to age and/or lack of teeth. Aged pet goats with broken mouths can be supported for several years by feeding pellets, softened, or other specialty feeds.
Two websites with photos illustrating how to age goats by looking at teeth include:
www.acga.org.au/goatnotes/B010.php and http://www2.luresext.edu/goats/training/management.html#mouth