Most cows have a natural lifespan of around 20 years, and they are only too old to breed after about 12 years of age, when they experience a significant drop in their fertility.
Although cows could theoretically expect to be able to breed up until around 12 years old, most cows are slaughtered before they get to that age due to injury or fertility problems.
In this article, we’ll be looking at when cows are too old to breed and the factors that affect their fertility, and learning why even when a cow is still young enough to breed, the farmer may not want them to.
When Are Cows Too Old To Give Birth?
Although it varies according to each individual cow, most experts agree that cow fertility drops at around eight to twelve years old.
In an article for Beef Magazine, Livestock expert Ron Torell explains that cows may see decline in their fertility after 11 years.
In another study by the University of Florida, it was found that there was a small decline after around eight years, and a more sharp decline in cow fertility after 12 years.
When Can Cows Breed?
Cows can usually breed from when they hit puberty, up until they are around eight to twelve years old.
For most cows, puberty occurs at around two years, although it varies a lot by breed and according to how they have been raised.
How Old Are Cows When They Can First Give Birth?
According to dairy expert Lindsay Ferlito from Cornell University, cows in the US typically give birth for the first time when they are around two years old.
This is because farm cows reach puberty at between 14 and 16 months of age and are usually bred straight away to maximize the profit per cow.
Farmers aim for the first birth to occur as early as possible, because an early first birth is positively correlated with the expected number of successful subsequent calves.
When Can Cows No Longer Give Birth?
Over the course of their natural lifespan of around 20 years, a cow could reasonably expect to give birth to around six to ten calves before their fertility started to decline.
Cows begin to see a decline in their fertility at around age eight, with a marked drop off around age twelve.
Although cows could theoretically give birth eight to twelve times, the lifespan of an average US dairy cow is only 4-6 years, with most calves producing between two and four calves in their lifetime.
This can be explained by the fact that milk production drops as cows age, yet the feeding costs remain the same. In addition, many cows develop problems such as mastitis, or problems with the hooves which lead to problems with milking.
Beef cattle are usually slaughtered at around three years old, so beef cows usually don’t live long enough to have calves. Instead, replacement calves are bought in or bred from specific cattle kept aside solely for replenishing the herd.
What Happens to Dairy Cows Once They Can No Longer Become Pregnant?
Dairy cows must be able to get pregnant, otherwise they can not produce milk.
Once dairy cows can no longer become pregnant, they are sent to slaughter.
Read More: How Many Times can a Cow Give Birth?
How Long Are Cows Pregnant For?
Cows are pregnant for about nine and a half months.
Dairy cows are typically pregnant for most of the year, with a break of between two or three months after each pregnancy required before the cow can be impregnated again. (The length of break required increases as the cows age)
Until What Age Can Cows Still Give Birth?
There is no set age when a cow suddenly becomes unable to give birth. The age differs for each individual animal based on their genetics, their environment, and their diet.
As a very rough rule of thumb, a cow can give birth up until around age twelve, after which point their fertility decreases rapidly.
Oldest Cow Who Has Given Birth
The oldest cow ever to have given birth was Big Bertha, a celebrity cow from Ireland known as being the longest lived cow in the world.
Bertha lived to the ripe old age of 48, and gave birth to her last calf in 1986, when she was 43 years old.
The calf was creatively named “Bertha Junior”.
When Are Heifers Old Enough To Breed?
Heifers are female cows who haven’t yet given birth to their first calf.
Farmers pay close attention to their heifers fertility, because every month a heifer spends not pregnant is an extra month the farmer has to feed her with no milk production.
Heifers go through puberty when they reach a certain percentage of their adult bodyweight, so farmers can accelerate the process by feeding the calves lots of energy dense food to help them grow faster.
Farmers tend to aim for a cow to give birth for the first time at around two years old, which means heifers need to be old enough to breed at around 14-16 months.
Calving at two years is positively correlated with fertility, longevity, and milk production rates over the rest of the cow’s life.
To sum up, most cows are too old to breed once they reach about 12 years old, although they rarely reach this age on a farm anyway.
The average natural lifespan of a cow is 20 years, but for dairy and beef cows on a farm this is cut to around 6 years and 3 years, respectively.
Cows go through puberty at around 14 to 16 months old, after which point they become fertile and are able to become pregnant. The first calf is usually delivered at 24 months.
Cows fertility gradually drops as they age, which affects their milk output too.
When a cow’s fertility drops to a point where it’s not worth it to feed her anymore, she is usually sold for meat in order to extract as much value as possible from each animal.
The oldest cow to have ever given birth was Big Bertha, a world famous cow who gave birth to a calf at 43 years old in 1986.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.