Pastures for horses should be more than mere exercise lots. High quality pasture can supply enough protein, vitamins, and minerals to meet the nutritional needs of most pleasure horses at relatively low cost. Although pastures furnish substantial amounts of energy, working horses will likely need additional energy supplementation. In addition, pasture will help to maintain healthy animals by furnishing the bulk needed in horse rations, as well as exercise areas, sunshine, and fresh air.
The pasture should be enclosed by a safe, strong fence. Fresh water and shade should also be provided. The pasture should be large enough to encourage normal animal activity and also be free from poisonous plants and obstructions such as holes or rocks which could cause injury.
Lacefield, Garry D.; Evans, J. Kenneth; and Baker, John P., "Horse Pasture" (1980). Agriculture and Natural Resources Publications. Paper 6.