10 August 2009

3 minute read

How do we measure for meat quality in Canada?

In Canada meat quality is measured by the amount of intramuscular fat in meat, which is referred to as marbling. The meat quality grades in Canada are A, AA, AAA, with single A grade beef having the least amount of marbling and triple AAA grade beef having the most, with the exception of Canadian Prime which has a slightly abundance amount of marbling. Marbling improves the flavor, juiciness and tenderness of beef.

How is intramuscular fat different from subcutaneous fat?

Subcutaneous fat is laid down on the outside of the carcass, while intramuscular fat is laid down within the muscle. As the amount intramuscular fat increases the quality of the beef improves. As the amount of subcutaneous fat increases the quality beef goes down. An excessive amount of external fat reduces the value of the beef.

What nutrient increases the amount of fat laid down?

Extra energy in a diet will produce additional fat. Fat is produced when the energy supplied exceeds the energy required for maintenance and production, (growth in feeders).

Is intramuscular fat & subcutaneous fat laid down differently?

Yes, subcutaneous external fat can be laid down more quickly towards the end of the growth curve, as the animal’s growth rate slows down. Intramuscular fat is laid down more slowly and is laid down continuously throughout the lifetime of a feeder.

Why is it important to understand this difference in the way fat is laid down?

It is important to understand the difference in how fat is laid down. If the slow continuous production of intramuscular fat is interrupted during the growth of a feeder, it can not be compensated for by feeding extra energy later in the finishing phase. This common practice only increases the amount of subcutaneous fat on a carcass.

What things might interrupt the production of intramuscular fat?

Drought, lack of milk, weaning, late castration and long distance trucking are a few examples of things that can interrupt the deposition of intramuscular fat. Treating sick animals more than once has also been shown to reduce the likelihood of adequate marbling.

What management practices will improve marbling in beef?

First cattle must have the genetics for marble, or no management practice will improve marbling. Assuming the cattle have the genetics to marble, anything that reduces stress and not limit the intake of high quality feed will allow for the continuous deposition of intramuscular fat, resulting in increased marbling. A few management things to do are: castrate early, creep feed, low stress wean, and vaccinate to reduce the likelihood of sickness.

Understanding the differences between subcutaneous and intramuscular fat deposition and managing animals to continuously deposit intra-muscular fat can improve marbling grades.

June 2009