Effect of zinc nutrition on parturition and postpartum in the rat

The effects of zinc deficiency on parturition were studied in three groups of Wistar rats. Group A received a zinc-adequate control diet (Zn = 33 ppm), group B received a zinc-deficient diet (Zn = 2.6 ppm), and group C received the zinc-deficient diet plus a supplement of zinc in the drinking water (100 micrograms/ml). The results showed a prolonged parturition (p less than 0.05) in group B (149 +/- 42 min) as compared to group A (78.6 +/- 23.7 min) and group C (82.4 +/- 20.8 min). No significant difference was found in regard to uterine bleeding. A different pattern of maternal behavior was found in the animals of group B who did not retrieve or lactate the pups. The importance of an adequate zinc status for normal parturition is stressed.