T: +44 (0)1432 272057

E: postroom@herefordcattle.org

Confirmed genetic defect carriers

DNA testing procedure

Please click the following leaflet to view sampling technique, sample codes and costings or click here

To see how to correctly take hair follicles view this short video:

To access known genetic carriers please use the following links:-


Partial to almost complete lack of hair. Affected calves are often born with very short, fine, kinky hair that may fall out leaving bare spots or areas particularly susceptible to rubbing. The condition may vary in expression as the animal matures and is usually less noticeable in older animals. The hair coat colour will sometimes appear "frosted" or "silverish". Tail switch may be underdeveloped.


Carrier Hereford bulls or females when mated to black cattle can produce offspring with a hair coat that is grey, smokey or chocolate colour.

Idiopathic Epilepsy

Age of onset or first seizure can be variable, ranging from birth to several months of age. Occurrence and persistence of seizures may be influenced by environmental stressors such as temperature extremes or increased physical activity. Upon initial onset of seizure episodes individuals will typically lie on their side with all limbs extended in a rigid state. Manual flexing of the limbs is possible but return to the extended position occurs after release. Seizure episodes may last from several minutes to more than an hour.

When conducting online searches, you may see animals which have codes listed in curly brackets { } between the animal and registration number. These codes represent the genetic defect the animal is known to be tested free of or a carrier of.

Currently used codes are listed below.

  • HYF = Hypotrichosis Free (tested and results indicate animal is not a carrier)
  • HYC = Hypotrichosis Carrier
  • DLF = Dilutor Free (tested and results indicate animal is not a carrier)
  • DLC = Dilutor Carrier
  • IEF = Idiopathic Epilepsy Free (tested and results indicate animal is not a carrier)
  • IEC = Idiopathic Epilepsy Carrier
  • PVF = Parentage Verified Free of all three defects
  • PVHF = Parentage Verified Hypotrichosis Free