Which cow has the lowest Net Energy for Maintenance (NEm) requirement?

The cow with the lowest Net Energy for Maintenance (NEm) requirement is the 1200 lb Brahman cow. NEm is a measure used to evaluate the energy needed to maintain the animal's body functions without production such as lactation.

Brahman cattle are known for their adaptability to various environmental conditions, particularly heat, which can influence their metabolic processes. This breed's efficient metabolism may result in a lower NEm requirement compared to other breeds. Additionally, Brahman cattle generally have a robust body condition that can influence their energy needs in a more favorable way as they are raised in environments where resource management is critical.

When considering the other options, the 1200 lb Simmental cow may have a higher NEm requirement due to its larger frame and the breed's typical production levels that necessitate more energy for maintenance. The crossbred cow with a genetic potential to produce 15 lb of milk per day suggests an investment in energy for lactation, which raises its NEm requirement further. Lastly, a 1000 lb lactating cow would have an elevated energy requirement due to the demands of lactation, making her NEm requirements even higher than that of the non-lactating Brahman cow.

In summary, the Brah