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Choosing a Dexter Bull

Why Selecting the Right Dexter Bull Matters

The bull you choose shapes the future of your Dexter herd more than any other decision. A superior herd sire lifts quality quickly; a poor sire can undo years of work.

I cannot stress enough how much care should be put into the selection of a sire for your Dexter herd. No other single investment is so important in determining the future caliber of the herd. The proper sire can, in just a few short years, create a superior herd from mediocre cows, but a poor sire can ruin an already well-established high-grade herd. Other breeders will often judge the value and importance of a herd by the quality of the sire at its head.

A bull is not just one animal of the many in your herd — the bull is 50% of your herd.

Conformation and Pedigree

 The physical structure and genetic background of a Dexter bull are critical. A well-built sire with proven conformation in his pedigree greatly increases your odds of producing consistent, high-quality calves. A bull with weak structure or poor udder genetics in his family line can set your herd back for years.

I personally prefer to raise a bull calf myself from weaning to adulthood. This allows me to observe his personality, halter train him, and feel confident handling him as a mature bull. There is always some risk, though — you won’t know if a young bull consistently passes on desirable traits until his daughters are milking. Even with careful study of the pedigree, disappointments can happen. For that reason, many breeders prefer to purchase a proven sire whose daughters already show good production and structure.

When purchasing a bull calf, look beyond his appearance alone. Review the physical characteristics outlined in our Dexter Structure Guide and confirm that good conformation runs consistently through his pedigree.

👉 At a minimum, his sire, dam, grandsires, and granddams should all show excellent structure, including strong udders.

The more proven conformations you see in a pedigree, the better the odds you’ll have a truly exceptional herd sire. Selecting a bull whose sire, dam, and sisters all have proven records takes some of the risk out of choosing a bull calf.

Temperament —

The Most Important Trait in a Dexter Bull

A Dexter bull’s temperament is the single most important factor in choosing a herd sire. A calm, steady bull will pass those qualities to his calves. An aggressive or unpredictable bull, no matter how good he looks on paper, can put your entire farm — and family — at risk.

Pay special attention to the behavior of a young bull calf. Even at six months old, the signs of poor temperament are there if you know what to watch for.

Warning signs include:

  • lowered head in a threatening stance

  • growling or grumbling noises

  • head-butting people (even in play)

  • erratic, wild, or flighty behavior

  • pawing dirt with the front feet

  • charging, even in short bursts

  • “staring you down” (trust me, you’ll know it when you see it)

At first, these behaviors may seem funny or harmless when a calf is small. But what’s amusing at six months can turn terrifying — and even deadly — in a full-grown bull. For that reason, we have a strict one-strike rule at Mountain Heritage Farm: one act of aggression and the bull is castrated. Period.

The temperament of your sire is more important than any other single member of your herd, because he will pass both good and bad traits along to his offspring.

All bulls we keep at Mountain Heritage Farm must have the classic “big dog” temperament Dexters are known for — curious, friendly, and calm. That said, even the best-tempered bull must be respected. When there’s a cow in estrus, a normally steady bull can have an off day.

👉 Farm Rule: Never turn your back on a bull, no matter how gentle he seems. Always have a safe route of escape planned before you step into the pasture.

Context Matters:

This is a full-blown threat display by Baloo — he’s posturing at the other bulls on the far side of the gate, not at a person. I was standing nearby in complete safety while filming because I knew this behavior was directed at other cattle and not at me. I am sharing the footage for educational purposes.

 

That said: if a bull ever fixates on you and shows this behavior — lowered head, intense stare, pawing, growling, aggressive posture — consider yourself in immediate danger. At Mountain Heritage Farm we have a zero-tolerance policy for aggression toward people. Any bull — regardless of age or pedigree — that threatens or aggressively targets a human is immediately removed from breeding (castrated and or sent to "freezer camp" as appropriate).

Bottom line: respect bulls, keep an escape route, and never turn your back on a bull.

Safety checklist:

  • Do not approach a bull showing this behavior.

  • Keep a solid barrier between you and the bull (gate, trailer, vehicle -- I was beside our Polaris Ranger).

  • Move calmly but quickly to safety — don’t run into a blind spot.

  • Call for help; don’t handle an aggressive bull alone.

  • If a bull targets a human, remove him from the breeding program.

Avoid “Overly Bullish” Calves

When shopping for a Dexter bull calf, resist the temptation to choose the one that looks the most masculine at just a few months old. Early masculinity may seem impressive, but it often signals early maturity — a trait that passes on to daughters. Early-maturing daughters can come into heat as young as four months old, which is a management nightmare since Dexter heifers should not be bred until at least 14 months of age (I wait closer to two years most of the time.)

It’s far better to select a calf that stays youthful longer. These calves may look less “bullish” in their first year, but they will mature in due time — and their daughters will cycle at healthier ages, closer to one year.

Napoleon, one of our herd bulls, still looked very much like a baby at six months old:

It may feel counterintuitive, but this slower development is actually desirable. If his sire matured into a strong, masculine bull, your calf will too.  Dexter bulls often take three to four years to fully mature, though by age two you should see clear muscling and masculinity.

Testicles and Reproductive Soundness

At two years old, Belle Fourche Baloo was in prime breeding condition as a young herd sire:

Healthy testicles are one of the most important indicators of fertility in a Dexter bull. A quality herd sire must have testicles that are the right size, shape, and placement — and it’s worth taking the time to check carefully before making a purchase.

 The penis of a bull is inside the sheath which should be held tight to the abdominal wall without any loose, excess skin.  The pink prepuce will often emerge before the penis.  This is fine, however, you don't want to see the prepuce all the time.  A bull that cannot retract the prepuce may have a problem and should be examined by a veterinarian.  

What to look for:

  • Both testicles should be equal in size, bean-shaped, and firm to the touch.

  • They should hang straight between the back legs, not twisted to either side.

  • Depending on the weather, a bull may hold them tight to the body (wrinkled scrotum) or let them hang lower (smooth scrotum). Both are normal. 

    📸 These two photographs were taken the same day of the same young bull.

Personal note:

Our very first Dexter bull came to us as a sprightly 5-month-old. As he grew, we discovered his testicles were malformed. One was small and underdeveloped, the other was too round, squishy, and fluid-filled. After consulting with our veterinarian, we decided to castrate him. It was a heartbreak, but it could have been avoided had we palpated his testicles before purchase.

On castration day, our vet confirmed the problem: he was likely sterile. That experience cemented one of our farm rules — always palpate the testicles of any bull you’re considering, or have your vet do it, ideally in a chute for safety.

 

Teat placement matters too.

Yes, Dexter bulls have teats, and their placement is predictive of udder structure in their daughters. Ideally:

  • Four small teats

  • Evenly spaced

  • Located on the abdominal wall at the junction of the scrotum

  • Moderate in size

 Poor teat placement in a bull is often tied to poor udder attachment in daughters. Having udder history for the dam and grand-dams adds even more insight into what you can expect from his female offspring.

👉 Remember: The bull is 50% of your herd. A thorough testicle and teat check is due diligence that will save years of frustration down the road.

Breeding Soundness Exams (BSE)

A Breeding Soundness Exam (BSE) can be a valuable tool when evaluating an adult Dexter bull. These exams check semen quality, motility, and morphology, as well as physical traits like scrotal circumference. However, you must proceed with caution: many veterinarians are unfamiliar with Dexter bulls, and this lack of context can lead to misdiagnosis.

Our experience:

We once had a veterinarian perform a BSE on a Dexter bull and declare him sterile. The recommendation was to butcher him. His scrotal circumference was deemed too small compared to standards for larger cattle breeds. The problem? Those “standards” simply didn’t apply to Dexters.

Thirty days later, we took the same bull to a professional semen collection facility experienced in working with small breeds. Their test revealed a healthy sperm count. In fact, that same bull had settled a cow (got her pregnant) just two days before the veterinarian’s exam.

👉 Lesson learned:

If you choose to use a BSE, make sure the veterinarian or facility performing it is familiar with Dexter cattle. Otherwise, results can be misleading — and you could lose a perfectly good herd sire.

Key takeaways:

  • A BSE can be helpful, but it’s not foolproof.

  • Dexter bulls are smaller than conventional beef breeds; size-based metrics don’t always apply.

  • Specialized AI/semen facilities often have better experience with Dexter proportions.

Disease and Genetic Testing

Health testing is non-negotiable when choosing a Dexter herd sire. A bull with hidden disease or lethal genes can devastate your herd and waste years of breeding effort. Responsible breeders test every sire, and as a buyer you should always ask for proof.

Standard Disease Panel

At a minimum, a Dexter bull should test free of the following:

  • BLV (Bovine Leukemia Virus)

  • BVD (Bovine Viral Diarrhea)

  • Johne’s Disease

  • Neospora

  • Anaplasmosis

  • Tuberculosis (TB)

  • Brucellosis

These diseases can spread silently through a herd, lowering fertility, triggering abortions, or causing long-term health issues. Buying only from tested herds protects your investment.

Genetic Testing for Dexter Cattle

Dexters carry two lethal genetic conditions:

  • PHA (Pulmonary Hypoplasia with Anasarca)

  • Chondrodysplasia (often called “bulldog calf” gene)

Your herd sire must be free of both. Even one carrier parent risks producing dead or severely deformed calves.

Trichomoniasis (Trich)

If you’re purchasing a proven sire (one that has already bred cows), require a Trich test.

  • Trich is a venereal disease spread by breeding.

  • Bulls infected with Trich are considered permanently infected — there is no cure.

  • Infected herds suffer infertility, repeated abortions, and devastating economic loss.

Cows can also be carriers, which is one of the many reasons we focus on placing heifers and bred cows from clean herds.

👉 Farm Rule: Every Dexter bull we use at Mountain Heritage Farm must be disease-free and genetically clear. Nothing less is acceptable.

In Summary

Most bulls are capable of settling cows, but only a select few can consistently improve a herd. A high-quality Dexter bull brings together all the traits that matter:

  • Correct conformation and structure

  • Calm, safe temperament

  • Healthy udders in daughters

  • Sound testicles and reproductive health

  • Clean genetic and disease status

A poor sire, on the other hand, can undo years of progress.

Never forget: the bull is 50% of your herd. Careful selection ensures your Dexter cattle not only thrive on your farm but also strengthen the breed for the future.

Ready to Add a Dexter to Your Farm?

At Mountain Heritage Farm, we set families up for long-term success with Dexter cattle. We place bred cows and heifers — never wet cows — so you can build trust during pregnancy and step confidently into milking when the calf arrives.

👉 Visit our Dexters For Sale page to see current availability and begin your journey with this remarkable dual-purpose breed.

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