The Irish Moiled breed was close to extinction in the late 1970’s and early 1980’s, with only 30 cattle left in the world. Due to dedicated breeders with the help of a grading up programme, the breed was brought back from the brink of extinction to reach the height of success it has in this present day.
The Irish Moiled Cattle Society was one of the first breed Societies to implement the rule that all cattle before being entered in the Herd book must be sire and dam verified using DNA analysis, which now spans back to almost twenty years ensuring the integrity of the breed for many consecutive generations.
Restructuring of the Society due to Brexit, allowed the Society to change to the more modern SNP DNA technique used for the sire and dam verified process which has brought about the added advantage of a whole new area of genetic evaluation now being available to the Irish Moiled breed that was not previously available with the older Microsatellite DNA technique.
Continuous advances in DNA technology now allow for the myostatin (double muscling gene) status of each animal to be identified. This new service was made available through ICBF to cattle Societies on 01/01/2023. Around 80% of all existing Irish Moiled cattle have been SNP’d and now have a known myostatin status, with a small percentage of the pedigree Irish Moiled population showing up as carrying a single copy of the myostatin gene, most likely originating back to the grading up programme implemented in the 1980s.
There are 9 different variants of myostatin in total, with 2 of the 9 variants appearing in the Irish Moiled breed. Myostatin results in increased muscling, a carcass benefit that increases the commercial value of the animal, however myostatin also results in some less favourable characteristics such as a higher birth weights (difficult calving’s), poorer milk yield, a reduction in female fertility, lower viability of offspring, delay in sexual maturation, decreased intramuscular fat and decreased external fat covering. These are amplified in cattle carrying a double copy of myostatin.
The Irish Moiled breed is renowned to be an easy-care breed of cattle, their ability to rear a calf on poor quality forage, whilst maintaining their fat covering and going back in calf to calve again the following year. They are an ideal breed to be used as conservation grazing. Irish Moilie beef is marketed based on its eating quality, marbling, and flavour.
The aim of the Society is to ensure the preservation of the breed, to promote and encourage the improvement of the Irish Moiled breed whilst maintaining the breeds purity and the breeds characteristics, which would be compromised by the myostatin gene. The Society has taken the decision to discourage the myostatin gene in the breed.
The actions that the Society have decided to implement to discourage myostatin within the breed are;
- The Society will notify as soon as possible (before end of March 2023) breeders who own bulls that carry one copy of the myostatin gene to help them make their own breeding decisions within their own herd.
- Any bulls that are displaying signs of extreme muscularity, i.e they are carrying 2 copies of the myostatin gene, (a double copy of the same variant or 2 copies of any 2 variants) will be entered into class 2 or transferred into class 2 from class 1 if already entered in the Herd book.
- All animals to be entered into the Herd book after 01/04/2023 that carry the myostatin gene will have their myostatin status detailed on the zootechnical certificate. Owners of bulls that carry the myostatin gene to be entered into the Herd book after 01/04/2023 will be given the opportunity by the Society to retract the registration request for that animal.
- The Society will endeavour over the next few months (before the end of June 2023) to let breeders know who own any females that carry the myostatin gene.
- Bull calves born after 1st Jan 2024 will only be entered into class 1 of the main section of the Herd book if they are free of the myostatin gene. Bulls born after 01/01/2024 with 1 or 2 copies of the myostatin gene, the owners will be given the opportunity by the Society to retract the registration request for that animal or if the breeder decides to proceed with the registration, then that animal will be entered into class 2 of the main section of the Herd book. (The Breeding Programme will be amended accordingly)
- Females born after 1st Jan 2024 that carry 2 copies of the myostatin gene (a double copy of the same variant or 2 copies of any 2 variants) will be entered into class 2 of the main section of the Herd book. (The Breeding Programme will be amended accordingly)
The Society over the next few months will try to educate breeders about the myostatin gene. A useful article to read is… https://www.beefshorthorn.org/beef-shorthorn-news/2001/myostatin-and-its-use-in-beef-shorthorn-breeding
It is important to stress at this point not to panic or make any rash decisions as the myostatin is a recessive gene. Anyone who owns females that carry one copy of the myostatin gene, should only use a bull free of the myostatin gene on them females.
The Society will constantly review the myostatin situation in the breed, and may implement more stringent rules in the future, if the level of myostatin in the breed increases.