Final answer:
The claim that mature, 48-month-old cows and bulls typically have a meat quality grade of choice or prime is false. Younger beef with the appropriate marbling is more likely to receive higher quality grades, and mature cattle may have tougher meat regardless of fat content.
Step-by-step explanation:
The statement provided in the question is false. Typically, cattle are slaughtered at an earlier age, when they are heavy enough for processing into different meat products, such as hamburgers and steaks. Cattle that are allowed to age, like those 48-month-old cows and bulls referred to in the question, may indeed develop greater fat content, but this does not necessarily mean that their meat quality grade is typically choice or prime. The USDA's quality grades of beef, which include prime, choice, and select, are based on factors including marbling (intramuscular fat), the color and texture of the meat, and the age of the beef animal at slaughter. Generally, younger beef is more likely to receive the highest grades, prime or choice, because the meat is usually more tender and has the desired level of marbling. Mature cows and bulls tend to have tougher meat, which may not grade as high despite a higher fat content. Additionally, diet plays a significant role in the quality of beef. Cattle fed on a grass-only diet may be considered healthier by some and can command a higher market price due to consumer preferences for grass-fed beef.