Other Factors Affecting Meat Quality

Age

Animal aging causes darkening of meat due to increased levels of myoglobin. Tenderness is also greatly affected by age. Although meat generally becomes less tender as the animal ages, this is not the case during periods of rapid growth when meat actually becomes more tender. This is because the connective tissue, which causes toughness, is diluted during periods of rapid growth. Although age is a factor in meat tenderness, it plays a less important role than factors such as muscle location and animal condition.

Meat flavor also intensifies with age. The flavor meat of older animals, especially sheep, may be so intense that some find it to be objectionable.

Muscle Location

Some muscles yield more tender meat than others. Muscles which are free to shorten during rigor mortis are generally less tender. Another factor affecting meat tenderness is the strength and usage of the muscle.

Diet

Provided there are no serious nutritional deficiencies, diet plays only a minor role in final meat quality. Starchy foods and sugars fed before slaughter can help restore depleted muscle glycogen levels to allow development of a normal postmortem pH.

Although not a meat quality problem, one undesirable effect of allowing animals to graze is yellow fat on the carcass. Grass contains high levels of beta-carotene, which can be stored in fat giving the fat a yellow color. Consumers often perceive meat with yellow fat as having come from an old or diseased animal. An undesirable "grassy" flavor may result from compounds found in forage. Consumption of wild onions and garlic can also give an undesirable meat flavor. For these reasons, animals should not be allowed to forage for several weeks before slaughter. Instead, they should be fed a grain diet.