Have you ever wondered why poultry is usually inexpensive? Part of the reason is because a 5-pound chicken can be raised from birth on less than 10 pounds of feeds. This is due, in part, to he nutritional value of the feed, which is readily converted into the chicken’s own tissues. Artificial diets are used for rearing many domesticated animals, artificial nutrients are used for growing plants hydroponically, and artificial foods are used for sustaining astronauts in space.
Some foods are more digestible and are more efficiently converted into an animal’s tissues than others. When creating artificial diets—or when simply trying to determine the best food source for an animal—it is helpful to have some method for comparing the quality of foods. There are two commonly used methods that measure the suitable of a food source for a particular organism The efficiency of Conversation of Ingested Foods (ECI) measured the quality of the food—that is how much of the food was converted into the animal that ate it. The other method is called Approximate Digestibility (AD) and measures how easily a food can be digested.
Overview

This time you will compare that artificial and the natural diet of the tomato bornworm in order to understand how ECI and AD measurements are taken. The ECI compares an organism’s weight gain to the weight of the food that it has eaten. The AD takes into consideration how much of the food was lost as waste.
The ECI and AD indicators can be used to study the value of many types of artificial foods and to compare them with an organism’s natural foods. This will determine whether an artificial diet is a more digestible and efficient nutritional source for a tomato hornworm than a natural food diet.
Is an artificial diet for a tomato hornworm as digestible and efficiently processed as the insect’s natural foods?