Experimental Investigations on the Effects of Dietary Deficiencies on Animal and Human Behavior

Spillage behavior and thiamin deficiency in the rat

Food spillage, food intake and body weight of four groups of adult rats were monitored daily as they were fed varying responses of deficient, marginal, or high thiamin (B) diet. Food spillage was a more sensitive index of the dietary B1 then either food intake or body weight change. Animals fed the deficient B1 diet exhibited the greatest levels of food spillage followed by the animals fed the marginal B1 diet. Hypophagia and weight loss occurred only among animals fed the marginal B1 diet. Feeding the high B1 diet to animals previously given the deficient and marginal B1 diets completely eliminated the excessive food spillage, and food intake and body weight returned to control levels. These data support the use of spillage behavior as a useful screening tool for detecting behavioral effects of inadequate nutrient intake or chemical intoxication.

Protein deprivation in primates. 3. Cage activities and chain-pulling behavior of adult rhesus monkeys maintained on low-protein diets

Three groups of adult female rhesus monkeys, maintained on low-protein diets (.5-gm, 1-gm, and 2-gm protein per kg body weight) were compared with a control group (4-gm protein per kg body weight) on a number of spontaneous cage activities and chain-pulling behavior. Although the deprived animals lost body weight and muscle tissue and they became deficient in essential amino acids and plasma albumin, they maintained their normal posture and continued to move about, vocalize, eat, drink, etc., as such monkeys usually do in their home cages. However, several specific behavioral deficiencies were revealed: reduced face and head movements, fewer eye contacts, and less chain pulling. It was concluded that the level of protein deprivation induced in this study depletes the animals' energy resources and produces a lowered anxiety threshold, so that certain additional behavioral demands cannot be supported even though routine cage activities are not impaired.