How long do sheep live? What is their life expectancy on a farm?

The topic of this article is going to be sheep lifespan. This is quite an interesting topic for multiple reasons. For example, most farmers don’t dwell on that question, but rather how long are sheep productive or fertile (until what age can they have lambs). But, let’s not jump ahead. I made some research and I hope I can give you a definitive answer to your question.

The life expectancy of a domestic sheep on a normal pasture is 10 to 12 years. Sheep with exceptionally good care can live up to 15 years, but it mostly depends on the sheep breed. Additionally, there are many documented examples of sheep living for over 20 years.

Don’t forget to read the rest of the article on this page, but I found a really great story on another website of a farmer who has multiple sheep over 20 years old on his farm. He really is an exception to the rule. Farmer’s story here.

How long are sheep fertile?

Let’s tackle sheep fertility (lamb productivity) first.

Quite an interesting fact is that sheep, like almost all mammals (except humans and a few other species (killer whales, short-finned pilot whales, beluga whales, and narwhals)) ovulate until their death. So, that would mean that sheep can have lambs until they die. While that might be true and good news for farmers, there are a few conditions that all farmers have to take into consideration and calculate their risks. Good access to food and health care. The older the sheep get, the better the grass and health care have to become. Lambs from old sheep have a slightly higher chance to be weaker and smaller. Also, older sheep might not have enough milk to feed their lambs, so those lambs might need extra care and attention.

Determine sheep age by teeth

Now, let’s get back to the main question of this article. How long do sheep live and how can we determine their age by their teeth?

Let’s cover sheep teeth basics first. Sheep get 20 milk teeth in total and later they get 32 adult teeth in total. Their teeth formula consists of incisors, premolars, and molars.

Determining sheep’s age by the status of their teeth is just an approximate method, but it’s the best one you can get for free. All we need to examine are sheep incisor teeth. When they are born, lambs get eight milk incisor teeth on their lower jaw. They don’t get any incisor teeth on their upper jaw. They have a dental pad instead. When they are one year old, the central pair of milk incisors gets replaced by a permanent pair of incisors. When they are 2 years old, their second pair gets replaced. By year 4, all lower incisors are replaced by their permanent versions. As the sheep gets older, past 4 years, those permanent incisor teeth will spread and wear, at the end even break. When the sheep has lost some of its incisor teeth it’s called a broken mouth. When it’s lost all of its teeth, it’s called a gummer. The sheep that has lost all of its incisors doesn’t have a problem with chewing food, only with grazing, especially very short vegetation. So, they can live on, you just have to provide quality food for them.

Determine sheep age by horns

There is one additional way to determine sheep age. We can calculate their age by counting rings on their horns. This is not an easy task as only a very trained and keen eye can differentiate a true annual ring (annuli) from a false ring. The false ones, by definition, don’t form a complete circle. This age calculation method is not possible on all sheep. It depends on sheep species and it mostly applies to males only as they usually have horns. I’ve found two species that you can use this method on: Thinhorn sheep and Bighorn sheep from North America.

How long do sheep live before slaughter?

If a farmer is raising sheep for their meat, then, every year he’ll probably try to send as much of his young sheep or lambs to the slaughter. He has to keep some young ones for herd rejuvenation. Most sheep intended to be used for their meat end on our tables before they reach two years.

Besides slaughtering lambs for profit, older sheep also get slaughtered or removed from the herd. This process is called culling. They get culled when the farmer notices that they are no longer able to produce quality offspring and quality milk. Still, there are many farmers that keep their old sheep until the end and let them die of natural causes.

World’s oldest sheep

There hasn’t been an official contender for the world’s oldest sheep for quite some time. When I type „official“, I’m referring to Guinness World Records data. The latest official „oldest sheep living“ was sheep called Lucky. In 2009. she died in a heatwave in Australia. There was another unofficial „oldest sheep living“ at that time, Methuselina, sad to be 25 years old. Unfortunately, she also died that year in a climbing accident. That was all a while ago and we are anxiously waiting for a new contender.

According to Guinness data, the oldest ever recorded sheep was 28 years and 51 weeks old when she died. That sheep was from Wales and died in January of 1898.

UPDATE: On the Guinness World Record site appeared a new „oldest living sheep“ called Grandma, born in 1994. The latest information on their site reveals that the resilient sheep is still alive. I wish for her remaining days to be filled with happiness.

Sheep age calculator

Many people like to play this fun, little game with various animals. Why don’t we try it with sheep? How would you calculate the human age of a sheep? One can better appreciate sheep if they convert sheep real age into their human equivalent. It’s quite an easy process.

Formula: =(age*4)+14

So, for example, a sheep that’s one year old is 18 years old in human equivalent. Sheep that’s 20 years old is 94 in human years. Quite an achievement.

There’s actually a site fully dedicated to converting random animal years into their human equivalents. Feel free to check it out, but don’t forget to get back to finish this article.

Can sheep die if it rolls on its back?

Let’s conclude this article with this not so bizarre question.

Well, yes. If sheep rolls over on its back, it may not be able to roll back and stand up on its own. It may need assistance. There is even a special name for sheep that have ended up on their backs. They’re called cast sheep. After some time, that sheep can get distressed. It’s vulnerable to predators, even crows. It can also suffocate like that. Grass ferments in its stomach and the fermentation process produces gas that can’t escape when the sheep is on its back. It builds up in the lungs and eventually prevents sheep from breathing. The most common reasons for rolling over are pregnancy, wet and heavy fleece, or maybe just combined shortness and fatness of the unlucky sheep.