Gut loading is the process by which an animal's prey is raised and fed nutritious foods with the intention of passing those nutrients to the animal for which the prey is intended. This term is used most often in reference to the preparation of insects, such as crickets and mealworms, or mice which are used as food for reptile pets. Insects that are raised commercially for the pet trade are themselves of little nutritional value. By providing the prey animals with a high quality diet prior to feeding, they become a more nutritious meal for the predator.
Gut loading can be accomplished by providing fruits, vegetables, and cereals or a nutritionally complete manufactured diet. Several commercial products are available and are fortified specifically for gut loading. These products often include varying combinations of carbohydrates, fats, proteins, vitamins, minerals, and dietary fiber.
Gut loading is considered most important if the primary source of nutrition is from insects. This is due to the fact that commercially raised insects are very nutrient poor compared to wild counterparts. This is especially true of vitamin A, among many other nutrients.
Gut loading is considered less important when animals such as mice are used as prey. This is because of the large amount of digestible energy and other nutrients a mammal contains in its tissues. It is also a less common practice when rodents are fed, because it is usually preferred to feed pre-killed prey from the store to protect the predator from being bitten.
Gut loading is designed to increase the nutrition of the prey's body and to fill the digestive tract of the prey with nutrients. As the term suggests, gut loading is usually looked upon as a way to get essential nutrients into a reptile via the ingestion of the digestive tract of the prey. The two methods of nutrient uptake are important due to the ability of the prey to process nutrients into a digestible form for the predator. For example, most prey can digest complex carbohydrates into other forms of nutritional energy which the predator can use. However, gut loading nutrients like calcium do not have to be digested by their prey before its death in order to be available to the predator.
- Merck Veterinary Manual. www.merckvetmanual.com