More On Their Rump, Less On Ours

Double muscling is a phenotype associated with a mutation in the myostatin gene so that it produces an inactive form of myostatin, unable to regulate muscle fibre deposition. Present in European beef cattle breeds such as the Piedmontese and Belgian Blue, it is characterized by an excessive increase in the size and number of muscle fibres within the animal. The meat of double muscled cattle is much leaner, with lower saturated fat content, both exciting prospects for the health conscious beef-lover.

Whilst the manipulation of the myostatin gene (through selective breeding) to produce these favourable characteristics seems attractive, double muscled animals homozygous for the mutant allele are less able to cope with environmental stress and are significantly more prone to birthing problems, making it ethically undesirable.

There are also several moral concerns which question the artificial mutation of the gene in slaughter animals other than cattle.

A suitable compromise is reached by crossing double muscled breeds with normal cattle types to produce heterozygous offspring, thus achieving some of the advantages of the gene without compromising the animals’ welfare. Cattle with only one copy of mutant allele do not express the extreme double-muscled appearance, but yield carcasses with 7% more beef and 14% less fat than normal cattle types, and, due to hybrid vigor, also have a higher growth rate.

These attributes are obviously enticing to the producer with respect to increased profits, but also benefit the consumer as the demand for healthy, nutritional food becomes more prevalent in today’s society.

Posted by Emily Carter

Student Number: 41209842

Primary Reference

Bellinge R.H.S. et.al, February 2005, Myostatin and its Implications on Animal Breeding – A Review, Animal Genetics, Volume 36, Issue 1, pp 1-6, URL: http://www.blackwell-synergy.com/doi/full/10.1111/j.1365-2052.2004.01229.x

Secondary References

Elstein, D., Peabody, E., July 2004, Can You Have Your Beef And Eat It Too? Agricultural Research, viewed 29 May 2007, http://findarticles.com/p/articles/mi_m3741/is_7_52/ai_n6104326

Smith, T., 1999, Beef Leanness Gene Pinpointed, Harden, B., viewed 29 May 2007, http://www.ars.usda.gov/is/AR/archive/jun99/beef0699

Volk, E., The Myostatin Gene, viewed 30 May 2007, http://www.thinkmuscle.com/ARTICLES/volk/myostatin.htm

Turner, J., The Gene and The Stable Door – Biotechnology and Farm Animals, viewed 30 May 2007, http://72.14.253.104/search?q=cache:1-ITLgsbPD0J:bioethycs.univer.kharkov.ua/FAEM%2520ANIMFLS/The%2520Gene%2520and%2520the%2520Stable%2520Door%2520Jan%25202002.pdf+myostatin+regulation+in+slaughter+animals+%2B+moral&hl=en&ct=clnk&cd=3&gl=au