Final answer:
Water availability is a key environmental factor other than temperature that affects the energy requirements of beef cattle. Drought can lead to increased energy needs for the maintenance of health, and wind impacts evaporation rates, influencing hydration levels.
Step-by-step explanation:
An environmental factor other than temperature that influences when additional energy is required in beef cattle is the weather, specifically the availability of water. This is because cattle need sufficient water for digestion and metabolic processes, and a lack of water due to drought or other factors can increase the energy required to maintain health and production levels. Additionally, wind can also play a role as it affects the rate of evaporation and can lead to increased water loss, requiring more energy for the cattle to maintain hydration.