Investigation Into the Origin of the Myostatin nt821 Mutation in Highland Cattle

In late 2023 the Highland cattle community became aware of the presence of the myostatin nt821 gene mutation in Highland cattle. Testing soon confirmed the presence of carrier animals in all Highland populations, resulting in much speculation as to the source of nt821’s incursion into the breed. Cambus Glen Highlands was significantly impacted when we discovered that our stock bull was a carrier, and we decided to apply our diverse engineering and IT skills to investigate the origin of nt821 in a more analytical manner. We applied a probabilistic pedigree analysis on seventeen tested carrier animals, all with strong links to the USA or CA herdbook (what we termed the “North American Cluster”). For each animal we developed a pedigree that traced back to the relevant herdbook foundation animals - tracing back 60-80 years or roughly 10 generations. Our analysis identified two common UK bred ancestors in the North American Cluster likely primary nt821 carriers - LEODHAS OF DOUNESIDE (UK MRD726298, CA 2430 – born 1971) and another older bull, CALUM MOR OF BALMUICK (UK STM484340). LEODHAS was imported to Canada in 1973 by Glen Osprey Farm (GOF), where he has had a very significant influence on North American Highland genetics (see https://www.facebook.com/share/p/1EK1suJCYY/). CALUM MOR was born in 1945 and his introduction into North America is via multiple pathways – notably DONNACHADH OF STRATHALLAN, a bull imported into the US, and others. We recently became aware of a tested carrier bull registered in the UK and found that this animal’s pedigree is fully traceable within the UK herdbook. When his pedigree was included in our analysis the likely primary nt821 carriers identified were: EXHIBIT OF STRATHALLAN (RMP635874) LILEAS 2ND OF DOUNESIDE (MRD6120303) CALUM MOR OF BALMUICK (STM484340) Where EXHIBIT and LILEAS 2ND are sire and dam of LEODHAS OF DOUNESIDE. We believe this analysis provides compelling evidence that nt821 was introduced into the Highland breed in the UK prior to 1960. A summary presentation of our work to date can be found in the following link:    • Investigation Into the Origin of the Myost...   To validate and improve on the accuracy of this analysis we need more data, and we ask if any breeders are willing to share the status of their carrier animals, or have comments or questions regarding this analysis, to please send the information to hugo.howse@cambusglen.com.au. We will then include this data in the analysis, although the details of any specific carrier animal will remain strictly confidential. We will provide an update on this analysis as soon as there has been a significant development in this regard. Pedigree of AM PRIONNSA ODHAR OF BAIRNSLEY https://drive.google.com/file/d/11c54XlX1b...