The horse's diet always includes sufficient amounts of hay, grass, water and, if necessary, additional concentrated feed.

Supplementary feed may be necessary in certain cases to meet specific needs and prevent or correct nutritional deficiencies. Here are some supplements horses may need to support their health and performance:

1. Minerals and trace elements: Horses need minerals such as calcium, phosphorus, sodium and potassium as well as trace elements such as zinc, copper, selenium and iron. These are important for bone health, muscle contraction and other physiological processes.
2. Vitamins : Vitamins such as vitamin A, vitamin D, vitamin E and various B vitamins are essential for skin, eye, muscle and nerve health.
3. Proteins : High-quality proteins are important for muscle growth, tissue repair and immune function.
4. Fat : Fat can be an efficient source of energy for horses, especially high-performance horses. It also supports the absorption of fat-soluble vitamins.
5. Amino Acids : Horses require essential amino acids such as lysine, methionine and threonine to build and maintain proteins.
6. Omega-3 fatty acids : These fatty acids are known for their anti-inflammatory properties and can support joint health and the immune system.
7. Antioxidants : Antioxidants such as vitamin C and vitamin E protect cells from oxidative stress and support the immune system.
8. Electrolytes : During intense physical activity or heat, electrolytes such as sodium, potassium and chloride can be lost and may need to be supplemented to prevent dehydration and electrolyte imbalances.
9. Joint-supporting substances : For sport horses or older horses, supplements such as glucosamine and chondroitin can be useful to support joint health.
10. Supplements for gastrointestinal health : For stomach problems, supplements such as probiotics or prebiotics can be given to support intestinal flora and digestion.

It is important to note that a horse's needs can vary depending on age, activity level, health status and breed. Therefore, it is advisable to work with a veterinarian or qualified equine professional to determine your horse's specific needs and select the right supplement. A balanced diet and regular monitoring are key to maintaining your horse's health and performance.