When known, Registered Jerseys will now be identified as carriers or free of the breed’s newly discovered undesirable genetic factor, Jersey Neuropathy with Splayed Forelimbs (JNS). The information will be included in several reports from the American Jersey Cattle Association (AJCA). Specifically, Jersey breeders can find this information on official performance pedigrees and progeny reports, Jersey Genetic Summary (also known as the Green Book) lists and the online sire-selection tool, BullsEye.
A complete list of known JNS carrier bulls can be found on the home page of the online Green Book. Documents are available in PDF and Excel formats.
On November 20, 2020, the AJCA animal database was updated to include information from the Council on Dairy Cattle Breeding (CDCB) for animals known to be carriers through genotyping. Carriers of JNS will be identified with the acronym JNSC (JNS Carrier). Tested free individuals will be identified with the acronym JNSF (JNS Free).
JNS is attributable to a specific haplotype on Bos taurus autosome 6 (BTA6) of genotyped Jerseys. About 6% of genotyped Jerseys have been identified as JNS carriers; 94% are JNS free.
The AJCA Policy Regarding Undesirable Genetic Factors was recently updated to include this information upon direction of the AJCA Board of Directors in November 2020. The policy, including a description of the condition and procedures for reporting, can be found in the December 2020 issue of the Jersey Journal or online here.