EFFECT OF LOW DIETARY ZINC DURING LATE GESTATION AND EARLY LACTATION ON THE SOW AND NEONATAL PIGLETS

Abstract

Twelve pregnant sows were fed semi-purified diets containing either 13 or 63 mg/kg zinc (Zn). The animals were fed the diets during the last 4 wk of pregnancy (2 kg/day) and the two first weeks of lactation (ad libitum). Reduced level of dietary Zn did not affect (P > 0.05) weight changes of sows and no difference (P > 0.05) in food intake occurred during the ad libitum phase of the experiment. Low Zn sows showed lower plasma Zn at 100 (125 vs. 157 g/dL) and 113 (93 vs. 127 g/dL) days of gestation and at 7 (65 vs. 133 g/dL)) and 14 (59 vs. 99 g/dL) days of lactation. The differences were significant (P < 0.01) only during lactation. Copper (Cu), iron (Fe) and ammonia (NH3) concentrations in plasma and alkaline phosphatase activity (APA) of plasma were not affected by treatment. Parturition lasted 2.08 h in control and 4.54 h in low Zn sows (P < 0.1). Zinc, Cu and protein content of colostrum and milk were similar between groups. Low dietary Zn had no effect on litter size, birth weight, number of stillbirths and mortality up to 2 wk of age. Liveweight at 7 days was significantly higher in piglets nursed by low Zn dams but at 14 days of age no significant treatment difference was found. Zinc, Cu Fe, NH3 concentrations in plasma and APA in plasma of piglets were not significantly different at birth or at 7 days of age. At 14 days of age only plasma Zn was significantly reduced (P < 0.05). Low supply of Zn to dams had no effect on the performance of piglets during neonatal life. Key words: Zinc, sows, pregnancy, lactation, piglets