You must understand fixed overhead expenses in order to understand absorption costing and variable costing. Fixed overhead consists of expenses that do not change with your level of production. Examples of fixed overhead include rent, insurance, wages for permanent full-time employees, and lease payments on equipment.
Whereas it may be safe to start a horse as early as two years of age, you must reasonably moderate the demands you are about to place on the developing horse. One hour of riding work may be just fine for a fully developed horse, but it is most often unacceptable for a two-year old.
Thoroughbreds mature slightly earlier than quarter horses and other similar breeds. They are broken to ride starting around 18 months of age so that they are ready to race as 2 year olds. Warmbloods and draft horses mature later than average and may not be broke to ride or pull wagons until they are 3 to 4 years old.