Goat Teeth — How to Tell a Goat’s Age
How Long Do Goats Live and When Can They Breed?
How can you tell a goats’ age if you have no records, and how can you be sure a seller is telling the truth? There are some observational methods, such as goat teeth, that you can use to estimate their age. As each individual grows and develops at its own rate, these methods are not precise but can give you an indication. Goat teeth and horns are reasonably reliable indicators, although individuals vary in the rate of development and wear. Other features give additional clues but are subject to health, nutrition, genetics, and the life that the goat has led. These include goat weight, frame size, muzzle width, beard growth, muscle tone, “knee” (carpus) calluses, and joint noise.
Why Is It Important to Know a Goat’s Age?
Although goats all have the same basic needs, details can vary due to age, sex, breed, and individual requirements. Nutritional, activity, and comfort needs may vary, for example. If you plan to breed, you want to ensure that your animals are mature enough to meet their own physical requirements while carrying and feeding young. You will also want to be aware of goat life expectancy.
Goat Lifespan and Early Development
Goats may live 12–18 years, depending on their health, genetics, and lifestyle. The first two years are important for laying down strong skeletal structure and teeth, and for healthy physical and behavioral development. Well-balanced nutrition when feeding goats is vital during this time, preferably consisting of varied natural forage, with mineral supplementation if necessary.
How Old Do Goats Have to Be to Breed?
Although kids can become fertile at around five months of age, the ideal female goat breeding age for their first mating is their second autumn (at about 18 months old). This enables does to develop optimally themselves before putting their energies into nourishing offspring. Bucks also benefit from waiting until they are at least one year old before mating. Even then they should be restricted to ten does initially, although most should manage 25 the following year, and 40 from three years old.
How to Tell Age from Goat Teeth
Goat teeth are important for a long, healthy, productive life. The better the teeth, the more efficiently your goat can process feed and be more productive herself. During the first four years, tooth development is a good estimate of age. After that, tooth condition is a better indicator of health and production potential than of age. There are many factors affecting dental viability, such as sound early development, health, and abrasiveness of forage.
Do Goats Have Top Teeth?
Goats have eight lower front teeth, called incisors. There are no upper incisors. The bottom incisors butt against a toothless dental pad under the upper jaw. These are used to grasp and tear forage. The molars — further back and difficult to observe — do indeed include teeth in upper and lower jaws. They are used to grind forage and cud.
How Goat Teeth Develop
After birth, kids develop small incisors — known as “baby,” “milk,” or “deciduous” teeth — and these erupt from the center outward in pairs during the first four weeks of life. During the second year, these teeth start to wear and are gradually replaced by thicker adult teeth, erupting in pairs outward in a similar fashion. Goats gain a full set of teeth at around four years old. Thereafter, the teeth wear, spread, and gums recede, causing teeth to appear elongated, and eventually resulting in lost or broken teeth.
How to Tell a Goat Kid’s Age
Deciduous incisors generally erupt one pair per week from birth, so you can reckon a goat kid’s age as follows:
- 1st/2nd pair erupted: 0–2 weeks old;
- 3rd pair erupted: 2–3 weeks old;
- 4th pair erupted and growing: 3–4 weeks old;
- Starting to spread: 3–9 months old;
Spread and wearing down: around 1 year old.
How to Tell an Adult Goat’s Age
The first two middle permanent incisors emerge as a yearling approaches 18 months old, quickly followed by the second pair by two years old. In the following year, the third pair erupt, while the outer pair are replaced by four years old. Adult teeth are noticeably wider and may differ in color from baby teeth, which will be showing considerable wear at this stage. We can estimate age from when adult teeth replace deciduous teeth and their subsequent wear:
- Central pair: 1–1.5 years old;
- 2nd pair: 1.5–2 years old;
- 3rd pair: 2.5–3 years old;
- 4th pair: 3.5–4 years old;
- Signs of wear: 4+ years old;
- Spreading: 5+ years old;
- Lost or broken: 6+ years old.
As growth is continuous during the first four years, and wear is dependent on circumstances, your goats may quite normally be in advance or lag behind this ready reckoner. My own goats’ teeth were a case in point when I photographed them just after their birthdays. My two-year-old had her third set already growing. My hardy four- and five-year-olds showed very little wear, despite their high-fiber diet.
Goats with lost or broken teeth are retired from production and need softer feeds, such as pellets and specialty products, to maintain their nutrition.
How to Tell a Goat’s Age by Horns
Goats’ horns grow every year, so become longer and more curved as they age. The first two years show substantial growth; thereafter, growth is thicker but less deep. In some goats, you can actually see changes in texture or shade on the surface of the horns marking the different growing seasons — so you can literally count the rings! Often this is more defined between some years than others, so it is not an easy reckoner. Growth and ease of assessment vary between breeds and individuals.
How to Estimate Goat Age from Other Features
Although kids mature sexually within a few months, they continue to develop and grow until they are three or four years old. When you are familiar with the genetic line of your herd, you will recognize maturity in the frame size and muzzle width of your goats. As goat teeth develop, their muzzles may appear fuller and rounder. Early development issues may confuse your assessment: sick, stressed, or underfed kids hardly grow, and will be smaller than average. Goat weight and size are very much affected by nutrition and exposure to disease and parasites. Genetics also have an effect, as some breeds are selected to be fast growing.
If you have a goat with a beard, you may notice this lengthen and thicken with age. A goat beard may start with a few tufts in the yearling, and develop to a fuller luxuriousness at two or three years old.
Most goats bear calluses on the foreleg joints we term goat “knees” (although they are anatomically equivalent to our wrists). Kids, and normally yearlings, have beautiful furry goat knees that are gradually rubbed to calluses through use. Goats whose feed troughs are too low for comfortable feeding may kneel excessively. A goat walking on knees is severely lame and cannot bear weight on the front hooves. This may be a sign of foot rot or other hoof problems. Most goats have developed calluses by two years old, and wear varies greatly, depending on activity and environment. However, be aware that large calluses may indicate past or current discomfort.
Goat knees frequently click, especially in goats four or more years old. Although normally there is no pain at this stage, goats can develop osteoarthritis, just as we can.
Feral goats are at their peak at five to six years old and will decline thereafter. Well-cared-for domestic goats who are not worked too hard generally stay in good condition for longer, and they may not noticeably lose muscle tone until they approach old age. To maintain this level of health they need good nutrition, suitable housing, routine care, regular exercise, and mental and social stimulation. To this end, we need to ensure that we know what to feed goats, how to house goats, the basics of caring for goats, how to treat goat diseases, how to create goat playgrounds, and how to emulate their natural social lives.
CARDI Small Ruminants Programme http://csrp.cardi.org/
E (Kika) de la Garza American Institute for Goat Research http://www.luresext.edu/?q=content/ageing-goats
Originally published in the July/August 2019 issue of Goat Journal and regularly vetted for accuracy.