Linebreeding

A temporary experiment

Justification

The idea of linebreeding came about when our best looking cow had a beautiful bull calf in 2026. We knew that this guy had a great start and if he developed as expected, we would have difficulty finding an external herd sire that would match his pedigree and quality. Producing quality male stock after eight years of bringing in some of the top bulls on the prairies is but one reason for embarking on a linebreeding experiment. Another just as valid reason is challenging our herd's genetic pool to test its resilience against hidden recessive defects. A third among many other reasons is propagating known foundation genetics that would otherwise be lost at the end of a "prize" cow's breeding life. More on this later.

The curve ball

Our plan was to begin linebreeding in 2027 with the aforementioned calf after using our existing herd sire Leopold for an unprecedented third breeding season in 2026. Having only produced one female in 2025, we expected to sell the heifer and keep Leopold for an extra year. We briefly considered an import, whose price tag would require selling Leopold to "fundraise" for the cross border transfer. We casually offered Leopold as an alternative to one of our yearlings, Nemo, that was already sold to a buyer pending pickup.

It was a bit of a surprise when the buyer was willing to pay the higher fee for Leopold over Nemo and a purchase agreement was finalized. Then it all went south when subsequent number crunching showed the investment in an import was unwise at the time. We had to choose between importing and linebreeding. Besides having a reduced herd of only four females to breed in 2026, an import would have cancelled our plans to linebreed in 2027 althogether. As a result, we were stuck with this yearling of our own breeding to use in 2026 which made our linebreeding experiment begin a year earlier than planned. In the end, we expanded the experiment into two phases which are described below.

Nemo

Phase 1: Foundation preservation

Despite his diminutive size, Nemo has an impeccable pedigree and a conformation as good as any other bull with heritage breeding. He is the final product of our herd matriarch Clover, who is from a long line of productive dams. She, her dam, her granddam, and her great-granddam above her on the maternal line of her pedigree average 14.7 years old when they produced their final registered progeny. We don't know what other line can boast 55 calving seasons and 37 registered progeny from just 4 females.

At age 16, Clover was open in 2026 and retired from production. It became clear that using Nemo in a first phase would be our last chance to preserve Clover's genetic advancements from elite breeders over several decades. We had already decided years ago to use Clover as the main genetic source for our herd. After many years of females, she gave us a curtain call finale to concentrate her best genetics into our herd one last time. Nemo is the icing on the cake for Clover's long career in producing purebred Dexters. The more we think about it, the more we realize this was a good "decision" to keep Nemo to use on his half sisters and nieces.

Phase 2: Breeding our best

With the first phase underway, we begin to make plans for 2027 with Pacha, the product of Leopold and KD who is our best looking female. He will get up to eight related females to work with: four half sisters on his sire's side, a half aunt on his maternal grandsire's side, his dam's full sister, a cousin, and finally, his own dam. Yes, as much as it pains us to inbreed child to parent, we feel that his dam should not skip the inbreeding challenge. If KD passes the test, the genetics of Pacha and any other of her future progeny will be deemed robust and worthy of propagation. We wish we could have 5 KD's in our herd, but if 2.375 of her is the best we can do, it's worth a try.

Pacha is already shaping up to be a handsome specimen in his own right. It will indeed be difficult to find a better external alternative, import or domestic that matches his pedigree and conformation, so far. He is still very young and we will be watching his development closely.

Pacha

Due diligence

It goes without saying, but we are not linebreeding with our eyes closed. We are starting with a foundation cow with one of the best pedigrees on the prairies and using her final product. Then we'll be using a great bull from her best female product. Both bulls are from Leopold, who is the final progeny of an aggressive breeding program married to premium imported stock. This is a temporary exercise as the plan to acquire a bull for 2028 is already in the works. In the meantime, we are taking the opportunity to optimize our defining traits: deep, thick females with the best udders possible.

We have performed our due diligence. Our herd is already PHA free by obligate. We also performed chondrodysplasia testing on Leopold, Clover, and KD, who all tested negative even though we already knew they would. So, now it's on paper that these two bulls we are linebreeding are both chondro-free by obligate. We cannot be accused of propagating known testable defects nor common observable, non-testable ones. All of the parents are within the Canadian breed standard and the two young bulls are projected to conform as well.

Shifts in COI

(female herd and their progeny)

Coefficient of Inbreeding

After eight years of acquiring unrelated bulls, we are starting with an enviably low coefficient of inbreeding (COI). The average COI of the 5 females being bred in 2026 is only 4.70%. When paired with Nemo, the calculated average COI of their 2027 crop will be 15.21%. Likewise, in 2027, eight females will be exposed to Pacha. Their average COI is 5.41%. The 2028 crop of calves are expected to have a bit higher average COI in the upper teens.* This average will be skewed by KD being bred to Pacha resulting in her 2028 calf's COI of 29.40%.

*The additional three heifers being bred in 2027 are not yet registered, so the handy COI calculator at clrc.ca does not yet possess their pedigrees.

Final thoughts

Prior to becoming registered breeders, our experience has been with commercial beef production where linebreeding is a foreign concept. Nevertheless, we have been breeding Dexters for eight years and there comes a time when we should be confident in our stock. This experiment will tell us if our confidence is valid. It seems a bit conflicting to promote linebreeding and sell seedstock to others at the same time from a closed herd. We continually remind ourselves that linebreeding is temporary and likely unsustainable in small numbers. We will be back to buying and selling diverse stock along with the rest of the Dexter association members soon enough. Sharing superior genetics is still the best way to improve the breed as a whole. In the meantime, as we move through this exercise, we will learn much about linebreeding and its benefits. And we will let everyone know how it goes.

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