Zinc oxide at low supplementation level improves productive performance and health status of piglets

Use of ZnO at high doses (3000 ppm) for diarrhea prophylaxis in piglets is widely extended in postweaning Spanish diets, in compliance with the national veterinary regulation. However, European feed legislation limits total dietary Zn to a maximum of 150 mg/kg of complete feed. The objective of this study was to compare a new potentiated form of ZnO, HiZox (Animine), at nutritional level (150 ppm) with pharmacological dosage (3000 ppm) of regular ZnO in starter diets on the productive performance and health status of piglets in a medium-low health status farm. A total of 144 pigs at weaning (28 d of age) were distributed in 6 piglets/pen and 12 pens/treatment. In the prestarter phase (28 to 42 d of age), all pigs received the same commercial feed, including 3000 ppm ZnO. In the starter phase (42 to 63 d of age) (T1) included 3000 ppm of regular ZnO (2500 ppm Zn), and (T2) was supplemented with 110 ppm Zn from potentiated ZnO (HiZox). Average daily feed intake, ADG, G:F, and pig-MAP serum concentration, an acute phase protein commonly used as unspecific biomarker of disease or other acute phase reactions, were measured at 42 and 63 d of life. Pen of 6 piglets was the experimental unit and data were analyzed using the GLM procedure of SAS version 9.0. Piglets fed with T2-HiZox had improved ADG and G:F (P < 0.001) compared to piglets fed with T1-ZnO. In addition, at 63 d of age, the T2 group had a lower pig-MAP serum concentration than T1 group (1.71 vs. 0.95 μg/mL; P < 0.05) indicating higher health status in the T2 group. In conclusion, in low-medium sanitary conditions and in compliance with European regulation, HiZox significantly increased piglet growth compared to pharmacological dosage of regular ZnO in the starter phase. This can be explained by a better health of pigs expressed by a lower level of inflammatory protein pig-MAP.