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News > What is myostatin and what does it mean for your suckler herd?


What is myostatin and what does it mean for your suckler herd?

March 11, 2022

College of Agriculture, Food and Rural Enterprise (CAFRE) CAFRE Beef Technologist, Natasha Ferguson provides an introduction to a new knowledge & technology investigation project on myostatin within the suckler herds at the CAFRE farms. The impact of herd health problems and dystocia (calving difficulty) in particular on the profitability of the suckler beef industry is well understood. A study conducted by Teagasc highlighted that 87% of the BETTER Farm Beef Challenge ROI participants had caesarean sections performed on farm with some having up to 8% performed on cows within the herd. The situation in Northern Ireland is probably similar and on that basis it was deemed important to start work at CAFRE to examine the relationships between the myostatin gene and a range of health and production traits.

What is Myostatin?

The myostatin gene influences the production of a protein that controls the development of muscle in cattle causing what is commonly referred to as ‘double muscling’. There are nine known variants of the gene with four being predominantly found in the UK, E226X, F94L, Q204X and nt821. Some of the variants can be linked to larger calf birth weights resulting in increased calving difficulty.  Some of these variants are also linked to reduced milk yield, delayed puberty and reduced fertility in females. There are however some benefits to the gene with increased kill out percentages, improved conformation and increased meat tenderness.

If your stock bull or breeding cow has one copy of a myostatin variant it is classed as heterozygous, if it has two copies it is classed as homozygous. It’s important to know the status of the parents in order to predict the resulting progeny status (see table one for details).

The probability of a mating resulting in progeny carrying the myostatin gene
Table 1: The probability of a mating resulting in progeny carrying the myostatin gene

Why are CAFRE investigating the suckler herds for Myostatin 

AI companies and breed societies are increasingly providing myostatin information on their bulls. This provides one half of the breeding story and is useful especially as heterozygous animals may not exhibit extreme muscling and therefore are difficult to identify as carriers without being tested. For example the Shorthorn bull used at the Hill Farm Centre, Chapelton Emir is a heterozygous myostatin carrier meaning he carries one copy of the gene.

We have identified that in order to get a full understanding of the effects of myostatin variants within the CAFRE suckler herds and investigate breeding strategies to maximise calf quality that all females in the herd required testing. This has resulted in the four stock bulls and 161 females in the CAFRE Hill Herd being tested last year. The results indicated that 120 animals carry at least one copy of the myostatin variants F94L, Q204X and E226X, including two of our stock bulls. Going forward all progeny will be tested for myostatin status in order to follow animals from birth to slaughter and provide the industry with more detail in relation to breeding outcomes. We continue to investigate through the CAFRE suckler herds and will provide more detail to the industry at future Knowledge Transfer Events.  

Whether you are aiming for an easy calving herd or trying to produce the next fat stock champion it’s beneficial to know the myostatin variants in your herd. This will allow you to develop breeding plans to maximise the benefits and minimise the disadvantages. In addition for the industry to use the information accurately CAFRE would encourage all Northern Ireland suckler farmers to record sires when birth registering calves.