THE INTERNATIONAL MINIATURE CATTLE
BREEDERS SOCIETY AND REGISTRY ®
a division of Happy Mountain® Farm Inc.
The Bulldog Gene in the Dexter Breed and in Crossbred Animals
By:  Professor Richard Gradwohl, MS, MBA


For many years the scientific community has know of the Bulldog gene in the Dexter breed. The scientific name for this gene is the chondrodysplasia gene. In the Dexter breed it causes an abortion usually at 7 to 8 months although I have heard of full term calves. The calf is born dead and there are obvious abnormalities. The nose is pushed in and the head resembles a bulldog hence the name. Sometimes the viscera are not covered completely by the skin . The legs can be short and stubbed. Until recently you just took your chances about having a bulldog calf. Now things have changed.

Scientists at the University of Sydney in Australia have recently found the gene that causes this problem and after much effort have developed a test for the gene. This test is now available to Dexter breeders and breeds using the Dexter as one of the foundation animals in crossbreeding programs. The Dexter is a very desirable animal because of its usual docile nature, beef and milking characteristics. The advantages of the Dexter far outweigh any disadvantages due to the bulldog gene. Breeders have been willing to take their chances with the goal of getting a small docile animal good for milk beef and as a great pet. The Dexter has become a beloved breed enjoyed by many breeders across the US and around the world.

Dexter's are an excellent animal to use as a foundation breed in a crossbreeding program. Using two or more pure breeds in a crossbreeding program creates heterosis (highbred vigor or high performance). When the Dexter is used as a foundation breed the benefits are many but there is always a chance that the Bulldog gene can be present. We pretty much know how this gene can manifest itself and now with testing available we can control it.

Crossbreeding occurs naturally by nature or intentionally by man. When crossbred animals are isolated they tend to develop a new strain that breed similarly over time. The Hereford , Dexter, Texas Longhorn and many others are all good examples. The definition of a breed is , "a group of animals from a similar background that breed true within an acceptable range of standards". There are several breeds that have been developed using the Dexter as one of the foundation animals. The Wagu/Dexter cross, Belted Galloway/Dexter called the American BeltieTM, Angus/Dexter called the BarbeeTM, Hereford /Dexter called the Kentshire® and other breeds that have Dexter in them such as the Panda® and the Irish JerseyTM. All of these breeds with the exception of the Wagu cross and American BeltieTM are based on a Linebreeding program with only one bull being the foundation bull for the breed. These crossbred breeds are very desirable, beneficial and in high demand.

If desired, owners of Dexters and other breeds can now have their animals tested to determine if there is a carrier of the gene. We have had one Bulldog calf born here at Happy Mountain® farm. It was a breeding of an F-1H Kentshire® to a F-1D Kentshire®.

Out of all the breedings here at the research facility this was the only instance. However, this does not mean it won't happen again. Scientifically we know that both sire and dam must have the gene for the Bulldog to occur. If both parents have the gene there is a 25% chance of a Bulldog calf, which means a 75% chance of it not occurring even if both parents have the gene. If you mate a carrier of either sex to a carrier of the opposite sex the result will be 25% bulldogs, 25% non carrier calves and 50% carrier calves. If you mate a non-carrier of either sex to a carrier of the opposite sex the result will be 50% non-carrier and 50% carrier but no bulldog calves due to both must have the gene to produce a bulldog and then a 25% chance.

If you are the owner of Dexter animals or any animals where the Dexter is one of the foundation breeds you can have your animals tested for the chondrodysplasia gene. Or you can take your chances as we have done for years. You can call and request the forms, address and method for testing. If you have any questions please feel free to give me a call.