Which of the following best describes the purpose of supplements in horse feeding?

The purpose of supplements in horse feeding is primarily to provide additional nutrients that may be lacking in the horse's regular diet. Supplements are used to enhance the nutritional quality of the overall feed and to address specific needs related to the horse's age, health condition, level of activity, or performance goals. For example, if a horse requires more vitamins, minerals, or protein than what is available in its standard forage or grain, a supplement can help fill those gaps. This targeted approach ensures that the horse maintains optimal health and performance.

On the other hand, replacing main food sources would not be appropriate as it could lead to an imbalanced diet if not carefully managed. Increasing the texture of feed is not a primary goal of supplements; instead, texture often relates to the type of forage or grain used in the horse's diet. Limiting the horse's appetite is counterproductive in most cases, as the goal is to provide adequate nutrition to support the horse's health and activity levels rather than to restrict their food intake.