Moderate zinc-iron deprivation influences behavior but not growth in adolescent rhesus monkeys

Primate species demonstrate a prolonged period of development before reprod uctive maturity that includes distinctive periods of rapid growth in the la te fetal, late infancy and early adolescent stages. Rhesus monkeys resemble humans in this discontinuous pattern of growth and also in its relationshi p to brain development. Studies of zinc deprivation in rhesus monkeys have suggested an important relationship among growth rate, nutrient status and behavioral performance in infancy as well as adolescence. Recently, moderat e combined zinc and iron deprivation (intake 0.2 mg Zn and 0.8 mg Fe/d, com pared with control intake of 2.9 mg Zn and 1.7 mg Fe/d) during the adolesce nt growth spurt (29-32 mo of age) of female rhesus monkeys (n = 8/group) wa s shown to influence behavior without affecting growth. Behavioral assessme nts included the Continuous Performance Test, the Delayed Nonmatch to Sampl e Test and activity (measured with an actimeter), The behavioral syndrome w as characterized by reduced activity, reduced participation in behavioral t esting and slower response, These changes could be reversed or prevented to some extent by altering the diet to include tablets of powdered beef (addi ng similar to 1.7 mg Zn and 0.7 mg Fe to daily intake). The study suggests that behavior may be sensitive to the quality of the diet available during the period of rapid adolescent growth and development.