Which condition aligns with the principle of feeding horses according to their activity?

Feeding horses according to their activity level is essential for maintaining their health and performance. When a horse is more active, it requires more energy to sustain its exertion levels, which translates to a need for additional calories, often obtained from their diet. Adjusting the feeding regimen based on the work done ensures that the horse receives the appropriate nutrients to support its energy demands, muscle function, and overall well-being. This approach helps in avoiding both overfeeding and underfeeding, thus promoting optimal health and performance.

While other options might seem reasonable at a glance, they do not accurately reflect best practices in equine nutrition. Suggesting that all horses should receive the same diet overlooks the individual needs based on activity, size, and metabolic rate. Feeding horses only in the morning neglects the importance of regular feeding schedules suited to their workload and digestibility. Finally, the idea that grains should only be fed on rest days fails to recognize that many working horses require grain on active days to provide necessary energy, rather than reserving it solely for times of inactivity.