The hypothesis that Alfalfa hay gives horses the most amount of energy is proven to be true. Glucose is easily converted to energy in the horses’ bodies. Therefore, higher glucose levels means more energy is available to them.
Horses are herbivores and consume plants and legumes for food. Ideally, horses should be allowed to feed on pastures during the growing seasons. However, the need to house horses indoors and limited productive pastures necessitates the use of hay as the main source of food and nutrient for the horses.
What would happen if this science project were to be repeated using different animals like donkeys or goats?
The science project can be repeated comparing the glucose levels in young and older horses.
Hay for horses - http://www.omafra.gov.on.ca/english/livestock/horses/facts/info_hay.htm
Hays for horses and their characteristics - http://www.extension.org/pages/Hays_for_Horses_and_Their_Characteristics
Selecting quality hay for horses - http://www.agry.purdue.edu/ext/forages/publications/ID-190.htm
Horses should be handled by qualified handlers at all times to avoid injury.