DIETARY ZINC-OXIDE IN WEANED PIGS - EFFECTS ON PERFORMANCE, TISSUE CONCENTRATIONS, MORPHOLOGY, NEUTROPHIL FUNCTIONS AND FECAL MICROFLORA

The uptake and distribution of zinc in tissues and the effects of 2500 ppm dietary zinc oxide on health, faecal microflora, and the function s of circulating neutrophils were evaluated in weaned pigs. One group was fed a zinc supplement diet and another group was used as a control . All pigs remained healthy throughout the study, but the supplemented animals showed better performance than the controls. The serum zinc v alues rose rapidly. At autopsy, carried out at the age of 63 days, the zinc concentrations in liver tissue were 4.5 times higher, and in ren al tissue two times higher in the supplemented group than in controls (P<0.001). Microscopic examination showed increased lipid accumulation in hepatocytes from supplemented pigs. No effect on the number of exc reted Escherichia coli and enterococci per gram faeces or on the funct ions of circulating neutrophils was observed. Dietary supplementation with 2500 ppm ZnO for up to two weeks after weaning appears to be pote ntially beneficial in the prevention of postweaning diarrhoea in pigs.