The National Research Council of the National Academies provides documents on nutrient requirements of animals. The estimates provided in the tables in this Fact Sheet are based on recommendations from the National Research Council. Tables 1 through 5 display how nutrient requirements are expected to change with differences in body size or production. The tables display estimates for requirements of digestible energy, crude protein, and several minerals and vitamins.
| Size of Horse | Digestible Energy (Mcal/day) | Crude Protein (pounds) | Calcium (grams) | Phosphorus (grams) |
| Maintenance (1,000 pounds) | 15 | 1.2 | 18 | 13 |
| Maintenance (1,100 pounds) | 16.5 | 1.4 | 20 | 14 |
| Maintenance (1,200 pounds) | 18 | 1.5 | 22 | 15 |
Nutrient requirements are estimated from the National Research Council’s Recommendations for Nutrient Requirements of Horses (2007). Mcal is megacalories (1,000 Calories), a unit of energy potential.
