Final answer:
Grain-fed beef has a higher fat and calorie content than traditional grass-fed beef and requires more energy to produce, making it less efficient. Traditional grass-fed beef commands a higher market price due to its health benefits and better taste, but is more expensive to produce.
Step-by-step explanation:
The energy content of grain-fed beef differs from traditional grass-fed beef in several ways. Grain-fed beef is typically produced by feeding cattle a diet of grains, which results in beef that is higher in fat and calories. In contrast, grass-fed beef tends to be leaner with a different fatty acid profile that many consider to be healthier. However, producing grain-fed beef is less energy-efficient and more costly in terms of energy input. For instance, producing 100 kcal of grain-fed beef requires around 1,600 kcal of energy input, with much of the feed energy lost due to the low net primary efficiency (NPE) of cattle.
When we compare costs, traditional grass-fed beef is often more expensive for consumers due to the higher costs associated with maintaining pastures and the slower growth rates of cattle. However, it commands a higher market price due to its perceived health benefits and better taste.