19 August 2016
What does MSA beef have in common with Australian swimmer and Olympic gold medallist Kyle Chalmers?
In both cases, glycogen is critical in optimising a gold standard performance.
Leading up to a big event athletes optimise their performance by loading up their glycogen stores through energy-dense food. During a race swimmers use glycogen stores to power them through the pool, but notice how exhausted they are by the end. Lactic acid is produced in their muscles as their bodies use up glycogen stores, fatiguing their muscles and preventing them from repeating the same performance straight away. It takes time for the blood stream to carry lactic acid away and rebuild glycogen levels.
The same goes when preparing cattle for optimal MSA performance.
Filling the tank
Every animal has a certain amount of energy contained in its muscles in the form of glycogen or ‘the fuel tank’. The 30 days prior to slaughter are critical to ensure the fuel tank is filled. Glycogen levels are influenced by the amount and quality of the feed consumed in the run up to slaughter. Cattle receiving high levels of nutrition from feedlot rations or high quality pasture will have high glycogen levels. On the other hand animals with restricted intake or low quality feed will have significantly reduced glycogen levels.
At slaughter, as the muscles contract, glycogen is converted to lactic acid, causing the pH (acidity) of the muscle to fall. The more glycogen present in the muscle, the more lactic acid produced. Without an active bloodstream to carry the lactic acid away, the muscle pH will fall to the acceptable 5.7 and below.
Knowing what empties the tank
MSA research has found beef with a pH above 5.7 to be of lower and more variable eating quality. It often also has features such as dryness when cooked, reduced shelf life and cooking inconsistencies. In 2015-16, more than 5% of cattle presented for MSA were ineligible because they had a pH of more than 5.7. Stress caused by poor transport conditions, unnecessary handling and severe weather conditions deplete glycogen levels, which can take up to 14 days to replenish. This leaves cattle with limited time to refuel before slaughter, reducing eating quality.
To avoid an empty tank at the time of slaughter:
Cattle should be managed as a single mob for a minimum of 14 days prior to dispatch for slaughter, this includes no mixing or drafting. Cattle should be continually grazed or fed rations to a level that is adequate for growth for a minimum of 30 days prior to dispatch. Handle and muster animals quietly to reduce stress. Ensure cattle have access to water outside of transport. Load cattle quietly, preferably without using goads and electric prodders, and at the recommended densities set out in the trucking industry code of practice.For more, check out the MSA Beef Tips and Tools Kit.
