How Long Do Bulls Live? The Figure Most People Land On Answers a Different Question

Bulls can live about 20 years, and a well-kept few come close: the PBR bucking bull Bushwacker was 18 when he died in July 2024. Almost no working bull reaches that. A natural-service herd bull in a U.S. commercial cow-calf operation is usually bought as a yearling, works four to five breeding seasons, and leaves the herd between five and seven years old, culled for feet and legs, fertility, temperament, or injury. A steer raised for beef is harvested far earlier, at roughly 18 to 24 months of age. Three numbers, three different questions.

Where the 20-year figure comes from

The 20-year answer is real and it has a citation behind it. Albert De Vries and Marcos Marcondes, reviewing productive lifespan in the journal animal in 2020, write that the natural life expectancy of dairy cattle is approximately 20 years, set against a productive lifespan of 2.5 to 4 years for the average cow. That number describes biology with nothing else acting on it. No breeding pasture, no social ranking against a younger bull, no salvage market.

Publications written for people who actually own the animal give a shorter working figure. Amanda Cauffman of University of Wisconsin–Madison Extension puts it plainly: bulls, much like cows, can live ten to twelve years, while most stay active in the herd closer to four or five years.

Both statements are accurate, and they measure different quantities the way a lamp's rated hours and the hours it survives on a working set are different quantities. The 20 is a ceiling. The four to five is a forecast.

I learned what it costs to miss that distinction on a job in 2014. A lifespan line went to plate on a jerky carton because somebody in the approval meeting said it out loud and it sounded like common knowledge. Nobody asked for the source, including me. A retailer's sourcing team asked eight weeks later, the panel was reprinted, and my studio absorbed two days of reshoot on a layout I had already delivered and been paid for. I have checked every printed number against its originating document since. That habit, rather than any pasture experience, is why I went looking for the primary sources behind this one.

How long a herd bull actually stays in the herd

Run the arithmetic on a typical purchase. A yearling bought at about 15 months, turned out for four to five breeding seasons, is five and a half to six and a half years old when he leaves. That is the number to plan around.

The University of Nebraska–Lincoln's Bull Value Cow-Q-Lator, published by Shannon Sand, Randy Saner and Matt Stockton in February 2024, ships with defaults that say the same thing in money: four years of expected bull ownership, 25 cows bred annually, a 2 percent annual chance of death, a 5 percent chance of injury across his life, and $1,500 of salvage value at the end. Four years of service means replacing roughly a quarter of your bull battery every year. That 25 percent is arithmetic from a default assumption, not a national survey, and it deserves the qualification.

Cows leave on a different schedule entirely. University of Florida Extension's publication AN323, by Matt Hersom, Todd Thrift and Joel Yelich, reports a beef cow culling rate of 15 to 20 percent in any given year, and its age breakdown of culled cows is the part worth remembering: 53 percent are over ten years old, 32 percent are between five and nine, and only 15 percent are under five. Cows exit old. Bulls exit young, and they exit for reasons that have little to do with how long a bovine body can last.

The strongest case against everything I have just written is that averages hide the individual. A quiet, structurally correct seven-year-old who passes his exam, walks well, and settles 25 cows inside a 60-day window is better than the stranger you would replace him with, whose calving-ease performance in your herd is unknown. That argument is correct, and I grant it fully. The place it breaks is timing: a bull who fails during the season leaves open cows behind him and stretches next year's calving window, and his salvage value falls as he grows heavier and older. The decision hangs on his exam result and on whether your operation can absorb a season of open cows, with his birthday as the weakest input of the three.

Herd bull versus beef steer: two ages, two questions

Search results and AI summaries hand you both animals in the same breath, which is where the confusion starts. A herd bull's clock is set by reproduction and soundness. A beef steer's clock is set by the grading rules.

| Animal | Typical age at exit | What ends it | What sets the limit | |---|---|---|---| | Natural-service herd bull | 5 to 7 years | Failed breeding soundness exam, feet and legs, temperament | Fertility, structural soundness, salvage value | | Fed beef steer or heifer | Roughly 18 to 24 months | Harvest | Carcass maturity under USDA grading | | Cull beef cow | Over 10 for 53% of those culled | Open, bad teeth, advanced age | Reproductive performance | | Retired bucking bull | Career ends near 8, lives into the mid-teens | Retirement to stud | Athletic soundness, then genetic value |

The steer's ceiling is written into USDA's own standards. The Agricultural Marketing Service sorts carcasses into maturity groups A through E, with A maturity corresponding to roughly 9 to 30 months of age, and the Select grade and above are effectively closed to cattle past about 30 months. USDA's specified risk material rule adds a second wall at the same point, requiring the vertebral column to be removed from cattle 30 months and older, with age verified by dentition at the plant. Feeding a steer longer costs money and drops him into a lower grade. Almost nobody does it.

So a fed steer's age answers "when does the beef grade best." A herd bull's age answers "when does he stop settling cows on schedule." A 22-month figure tells you nothing about the animal standing in your breeding pasture, and a 6-year figure tells a feeder nothing at all.

What ends a bull's career before biology does

The breeding soundness exam ends more bull careers than anything else, and the thresholds are published, so there is nothing mysterious about them. The Society for Theriogenology form, reproduced in NDSU Extension's bulletin on bull breeding soundness examinations and in New Mexico State University Guide B-232 by extension veterinarian John Wenzel, sets three minimums.

| Bull's age | Minimum scrotal circumference | |---|---| | Under 15 months | 30 cm | | 15 to 18 months | 31 cm | | 18 to 21 months | 32 cm | | 21 to 24 months | 33 cm | | Over 24 months | 34 cm |

Alongside that measurement, a satisfactory classification requires at least 30 percent progressively motile sperm and at least 70 percent morphologically normal sperm, plus a clean physical exam covering eyes, feet, legs, and reproductive organs. Scrotal circumference carries weight beyond the bull himself, since it tracks daily sperm output and runs inversely to the age at which his daughters reach puberty.

Failure rates are lower than the folklore suggests. NDSU reports that of roughly 5,800 bulls examined by North Dakota veterinarians in 2014, 9 percent of mature bulls and 17 percent of yearlings failed. The current revision of that bulletin, updated in September 2025 by Lacey Quail with veterinarian Jake Galbreath, also notes that about 35 percent of 12-month-old bulls are reproductively mature, rising to 95 percent by 16 months, which is why a young bull's first exam should be scheduled with his birthday in mind.

I used to repeat the advice I had read most often, which was to sell any bull the day he fails. I stopped giving that answer around 2021, after reading the NDSU figure that nearly half of yearling bulls initially deferred were later classified satisfactory. A deferred bull and an unsatisfactory bull are two different verdicts on the same page, and treating them as one throws away sound animals over a temporary problem.

Here is where my own experience runs out. I have never managed a breeding pasture, and I cannot tell you from having stood there what a bull's gait looks like the week his feet start to go. The people who can are the ones I read: UNL's G2332, written by Karla Wilke, Kacie McCarthy and Hannah Greenwell in 2021, lists the culling triggers as poor vision, low semen quality, undesirable conformation, injuries to reproductive organs, structural injuries, and aging out of the bull battery. What I can vouch for is that every number in this article traces to a named document I opened myself.

The cow load you give him shapes how many years you get

Overloading a young bull is a slow way to shorten his career. UNL's G2332 gives yearlings of 12 to 16 months a mating capacity of 10 to 15 females, and bulls of 30 months and older 25 to 30 females, with one mature bull per 25 cows as the standard recommendation for a 60-day season. The full defensible range runs from 1:10 for yearlings in synchronized natural service up to 1:60 for mature clean-up bulls following AI.

A rule of thumb circulates for young bulls: cows equal to his age in months, applied up to about 30 months. A 15-month bull covers 15 cows. It is crude, and it agrees closely enough with the published tables to be useful in a sale barn.

For synchronized herds, SDSU Extension's Robin Salverson points at the Healy work from 1993, in which a 1:25 ratio under synchronization produced an 83 percent pregnancy rate and the best economic return of the ratios tested. Synchronization compresses the work into days rather than weeks, which is exactly when an underpowered bull battery shows up in your calving distribution the following spring.

The annual sequence that decides whether he stays

1. Score body condition about 90 days before turnout, targeting 5.5 to 6.5 on the nine-point scale, per UNL's G2332.
2. Book the breeding soundness exam 30 to 60 days before turnout, the window NDSU recommends. UNL's four to six weeks falls inside it.
3. Have feet and legs examined, and trim at least two months out, since lameness suppresses libido and depresses semen quality for months afterward.
4. Read the classification rather than the pass or fail: satisfactory, unsatisfactory, or deferred. Retest a deferred bull no sooner than 30 days later.
5. Match his cow load to his age using the published capacity tables before you build breeding groups.
6. Make the cull decision in fall if he already carries a known problem. Cauffman's cost note is blunt about it: six months of decent hay for a mature bull runs about $600, spent on an animal you have already decided to sell.

Questions cattle owners actually ask

What is the natural lifespan of a bull?

About 20 years. The figure comes from the biological literature, including the De Vries and Marcondes review in animal, which puts natural life expectancy for cattle at approximately 20 years. It describes an animal under no production pressure. Commercial herd bulls rarely see half of it, and most leave the herd before seven.

What happens to bulls when they get old?

Most are culled and sold, usually after failing a breeding soundness exam or going lame in the feet and legs. They enter the beef supply as cull bulls, priced by weight rather than pedigree. A small number of proven sires continue in semen collection, and retired bucking bulls generally go to stud on the contractor's ranch.

How long do bulls live in captivity?

Ten to twelve years is the practical figure University of Wisconsin–Madison Extension gives for cattle kept in good condition. Bulls held for value rather than production can beat it: the PBR champion Bushwacker, born in 2006, died in July 2024 at 18 years old. Veterinary attention and a light workload after retirement explain most of that gap.

How long do bulls breed?

A bull can settle cows from roughly 12 to 16 months old, once he passes a breeding soundness exam, and stays capable into his teens if he remains sound. The commercial answer is much shorter: four to five breeding seasons. Fertility peaks in the young mature years and drifts downward after five or six, with wide variation between individuals.

How long does a cow live before slaughter?

That depends on her job. A heifer fed for beef is harvested at roughly 18 to 24 months, since USDA grading favors A maturity of about 9 to 30 months. A beef cow kept for calves lasts far longer: University of Florida Extension reports 15 to 20 percent culled yearly, 53 percent of them over ten.

What makes a bull fail a breeding soundness exam?

Falling short of any Society for Theriogenology minimum: scrotal circumference for his age, which starts at 30 cm under 15 months and reaches 34 cm past 24 months, 30 percent progressively motile sperm, or 70 percent morphologically normal sperm. Physical defects fail him as well, including bad eyes, unsound feet and legs, and injured reproductive organs.