Protein deprivation in primates: XII. food preferences of juvenile rhesus monkeys.

21 male and 18 female juvenile rhesus monkeys whose mothers' prenatal diets varied according to protein content (either 1-, 2-, or 4-gm protein/kg body weight/day) were given a food-preference task. 20 monkeys were between 3 and 4 yr. old; 19 were between 1 1/2 and 2 1/2 yr. old. For each trial small pieces of the same type food were placed in 8 equally spaced wells about the circumference of a circular tray held outside each monkey's cage. Responsiveness to the 21 natural foods (assorted cheeses, meats, vegetables, nuts, cereals, fruits, and candies) offered 3 times on 3 different occasions was measured by recording number of pieces taken, number eaten, and elapsed time for taking all 8 pieces. All 3 measures were highly correlated. All diet groups exhibited the same general order of preference, males taking and eating more food pieces faster than females. Order of preference was significantly different for old versus young juveniles, with older juveniles' preferences more similar to those of adult female monkeys given the same task. The most notable differences in eating behavior were that younger juveniles played with their food and were less finicky about what they ate. Results suggest that food preferences of juvenile monkeys are not altered as a consequence of their mothers' prenatal protein deprivation.