Whether horse or human, a balanced diet involves the correct balance of nutrients to meet the body’s daily requirements. These include protein, amino acids, fatty acids, carbohydrates, vitamins and minerals. For horses, a balanced diet is rarely supplied by grass or forage alone. Grass is often deficient in key nutrients, including copper, zinc and selenium. It’s important to correct potential deficiencies by supplementing the diet, but a guesswork approach using occasional scoops of compound feed is unlikely to balance the shortfall properly.