Some behavioural effects of prenatal marginal zinc deficiency in young rats

During pregnancy rats were fed either a marginally zinc deficient (18.33 ppm zinc) or a control diet (about 100 ppm). At birth control offspring were fostered to other control dams or cross-fostered to zinc deficient dams. All deficient pups were cross-fostered to control dams. Neonatal mortality was higher in zinc deficient pups. At 14–15 days of age, deficient pups opened their eyes earlier and control pups cross-fostered to deficient dams were heavier and emitted more ultrasonic distress calls than pups from the other groups. They also spontaneously alternated the most at 28–31 days and, along with deficient rats ambulated more than control rats fostered to control dams. At 56–64 days rats in this latter group were lighter than all other rats. For males only, 56–64 day old deficient rats achieved the highest ambulation counts. Control females of this age fostered to control dams showed the lowest female preference for novelty. The results were discussed in the light of complex relationships between prenatal marginal zinc deficiency, postnatal maternal influences, sex of the rats and possible zinc toxicity in control animals.