High dosage of zinc oxide (ZnO) in piglet feed has been widely used to control post weaning diarrhoea (PWD).
In the modern pig industry, weaning generally occurs 21-28 days after birth. The administration of high dosage of ZnO usually lasts about 14 days, starting immediately after weaning. ZnO inclusion in piglets diets should reach an optimal concentration of 2500 ppm Zn (equivalent to approximately 3100 ppm ZnO). Supplementation of high dosage of ZnO not only results in the lower mortality and reduced PWD symptoms but also improves piglets’ growth performance. However, due to its negative environmental impact, the EU commission has banned the use of high dosage of ZnO in weaned piglets diets, allowing 150 ppm Zn supplementation since June 2022 and resulting in significantly increased cost of antibiotics treatments. Table 1. shows the effect of reduced ZnO concentrations on piglets performance.
The coated zinc oxide has the larger surface area and coated with the enterolysis polymer material to avoid acidic stomach loss. Therefore, coated ZnO could significantly reduce ZnO supplemental levels but achieve the equivalent effect to the high dosage of ZnO. Table 2 compared the effect of normal ZnO with coated ZnO. It is clearly shown that using 1500 ppm coated ZnO (900 ppm Zn) achieved the equivalent effect on piglets’ daily gain and diarrhea rate. If supplemental level of coated ZnO is below 1500 ppm, it will compromise piglets daily gain and increase the diarrhea rate.