If you’re just entering the world of mini-cattle this is a really good question. The simple answer is that DNA testing is ALWAYS recommended when there is any question whatsoever about your cow or bulls chondro status. There are a few things that may make you suspect that your calf, cow, or bull is chondro positive:
1) one of their parents is chondro positive
2) one of the parents is under 40” and you have no record of that parents breed profile.
3) one of the parents is full or part Dexter (this breed is the primary carrier of the chondro gene in mini-cattle)
4) the animal in question has proportionally short legs and/or is especially thick built
5) the animal in question is at or near full grown and under 40”.
Why does it matter if they are chondro positive vs naturally short?
Breeding risk!
If you don’t plan to breed them, it really doesn’t matter. However, if you do plan to breed them then you’ll want to avoid breeding two chondro positive animals together as the likeliness of them producing a stillborn or severely deformed calf is 25%.
Complicated pregnancies!
Many breeders chose chondro bulls over chondro cows if they are intentionally breeding for the chondro gene. The reason is that a smaller chondro sized cow is going to experience a higher risk pregnancy than her mini or mini-mid size equivalent. If the calf is too big to delivery naturally, both cow and calf may be lost. If you choose to go this route, I highly recommend talking to breeders that have experience doing this (not us).
Higher value calves!
All breeders of mini highland / dexter crossbred cattle (commonly referred to as mini-highlands) will typically DNA test calves that are suspected chondro positive. The DNA report is then given to the new owner regardless of the new owners breeding aspirations. As chondro positive animals are so popular, they command a higher price tag which means that most any breeder would want to know if their calves are positive before setting a price. Bottom line is that the chances are pretty good that DNA results will be available at the time of sale if you are buying new cattle, but if they aren’t, you’re planning to breed, and you suspect that your new cow or bull are chondro, get them tested!
For more information on this visit UC Davis testing center at: https://vgl.ucdavis.edu/test/dexter-bulldog-dwarfism