As a rough guide, it takes about three years to raise a cow for slaughter, however the exact time depends on the breed of cow, the desired use for the meat, the personal preferences of the farmer, and the physiology of each individual animal.
In this article, we’ll be looking at exactly how long it takes to raise a cow for slaughter, and the questions around how long it takes for a cow to grow to full size, the differences between different types of cow, and some edge cases like veal and dairy cows.
How Old Are Cows When They Are Slaughtered?
Different types of cow are slaughtered at different ages. As a baseline, regular beef cattle which are raised from calf for beef are slaughtered at around 32 to 42 months of age according to the USDA.
According to Angus cattle specialists South Fork Angus, angus cattle reach their full size bodyweight at around two years old.
Since Angus cattle are the most widely raised beef cattle in the US, this makes sense and ties in with the USDA figures above, allowing some time for calving and muscle growth before slaughter.
Although regular beef is slaughtered at between two and three years on average, there are many other situations in which cattle may be slaughtered much younger or much older than this. Let’s take a look at some of them:
How Old is Veal When It’s Slaughtered?
Veal calves are usually male dairy calves, which are an unwanted byproduct of the dairy industry caused by the fact that dairy cows must be kept perpetually pregnant to ensure continuous milk production.
Since they can not produce milk and the thinner bodies of dairy breeds aren’t efficient for beef, they are usually sent to a veal farm soon after birth.
Veal is typically around six to eight months old at the point of slaughter, although even within the category of veal there are different types.
Bob Veal – calves which are fed an iron-deficient liquid-only diet and slaughtered at only a few months old.
Veal – Calves which are around six to eight months old at the point of slaughter
Rose veal – Calves which are between eight and twelve months old at the point of slaughter.
Read more about veal in our article – What is Baby Cow Meat Called?
How Old Are Dairy Cows When They Are Slaughtered?
Dairy cows are more profitable to the farmer for producing dairy than they are being sold for meat, so dairy cows are only sent for meat once they can no longer produce milk.
As dairy cows get older, they can no longer reliably become pregnant and their milk production decreases.
When the dwindling milk production means it is no longer economically viable for the farmer to keep feeding them, dairy cows are sent for slaughter.
Dairy cows are typically sent for slaughter when their milk production and fertility starts to drop off at around six to eight years old.
Read more: When are cows too old to give birth?
How Old Are Bulls When They Are Slaughtered?
Like dairy cows, bulls are more profitable to the farmer when they are carrying out their specific task, rather than being raised for meat. In the case of bulls, this is reproducing and increasing the herd size.
Bulls help create new cattle, which may be used for either dairy or beef depending on the bull breed.
The value of a bull comes from their genetics and their ability to create new cattle. When a bull can no longer reliably reproduce, they are sent for slaughter.
In an article for Hereford magazine, Hereford Bull expert Ron Skinner explained that peak fertility is at around four years, and it’s common to see a rapid decline in bull fertility at around 7 years of age.
Many bulls develop leg or hoof problems long before they start to see a decline in fertility, which makes breeding difficult or impossible for them and results in them being sent for slaughter sooner.
Bulls are typically sent for slaughter when they develop injuries which prevent them for breeding, or when their fertility starts to decline between four and seven years of age.
Read more: Can we eat meat from bulls?
How Long Until A Cow Is Fully Grown?
Cows typically achieve their maximum body weight at around two years old, however their body composition continues to change after this, so beef cattle are raised until about 32-42 months old to achieve a nice fat/muscle structure (marbling) on the beef.
Best Age To Slaughter A Cow
The optimal age to slaughter a cow really depends on the goal of the farmer. Maximizing profits from a cow might mean slaughtering it early, but maximizing the quality of the meat might mean feeding it for an extra year to build more muscle.
Dairy cows and bulls are usually only killed once they are too old to be useful, and veal is usually slaughtered within a few months because it’s not economical to feed them.
As a general rule, the optimal age to slaughter beef is around 32 to 42 months of age. This maximizes the quality of the meat, and ensures that the cows have reached their full size.
Can You Slaughter A Cow At Any Age?
Yes, you can slaughter a cow at any age, however there is an optimal age for meat quality.
Cows which are slaughtered too young provide meat which is lacking in color and nutrients (veal) and cows which are slaughtered too old have tough, muscular meat which is not suitable for steaks and other prime cuts (bulls and barren dairy cows).
How Long For A Cow To Become An Adult?
In a research paper from the American Journal of Animal Sciences, it was found that the average age at which a cow reaches puberty is 357 days, although they don’t reach their full body weight until around two years old.
To sum up, cows get slaughtered at various different ages depending on what type of cow they are, and why they are getting slaughtered.
Regular beef cattle are usually slaughtered at around 32 to 42 months old, since at this age they are fully grown, and their muscles have developed enough to give the meat a nice marbling.
Some other types of cattle are only slaughtered once they are no longer useful for other purposes. Examples of this are dairy cows who can no longer produce milk, and bulls who can no longer reliably reproduce.
Male dairy cow calves are typically slaughtered at six months or earlier. Since they can’t produce milk and they are not a good breed for beef, it’s not worth the time and money to feed them.
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.