Effect of pharmacological dietary doses of zinc oxide on performance and fecal characteristics of weanling piglets

In a study with 135 weanling piglets (8.5 kg average initial body weight) 3 levels of ZnO were added to a conventional diet (0 mg ZnO (control), 2000 mg or 3000 mg ZnO per kg of diet). The mixtures were fed ad libitum for 3 w eeks. Subsequently, the control diet was fed to all animals for another 3 w eeks. During the entire experiment the ZnO treatment did not affect weight gain, feed intake nor feed conversion rate to a statistically evident extent (ove rall means: 365 g/d, 771 g/d, and 2.12 gig). Also fecal consistency and fec al dry matter content remained unchanged. The ZnO addition increased the Zn concentration of fecal dry matter from 1.7 mu g/g (control) to 12.8 and 21 .6 mu g/g, respectively. After 3 weeks of feeding ZnO the Zn concentration in blood plasma were increased from 0.72 mu g/ml (control) to 0.76 mu g/ml and 0.88 mu g/ml, respectively, while the contents of Cu and hemoglobin rem ained unchanged (overall means: 1.32 mu g Cu/ml plasma and 11.2 mg/100 ml w hole blood).