Tolerance and safety evaluation of sodium sulfate: A subchronic study in laying hens

Abstract Sodium sulfate (Na2SO4) is a readily available chlorine-free source of sodium, which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets. Dietary supplementation with excessive levels of Na2SO4 might be detrimental to bird’s health and performance. A subchronic study was carried out to investigate the potential adverse effects of an accidental oversupply of Na2SO4 in the diets of laying hens. Four hundred and fifty 21-week-old Hy-Line White layers were randomly assigned to 5 treatments with 6 replicates. The birds were fed diets supplemented with 0 (control), 0.3%, 0.6%, 1.5%, and 3.0% Na2SO4 for 8 weeks. Laying performance, egg quality parameters, clinical blood parameters, histopathology, intestinal barrier functions, and intestinal microflora composition were measured. No clinical signs of intoxication or mortality were observed during the experimental period. The results of this study showed that the optimal levels of Na2SO4 (0.3% to 0.6%) significantly improved the laying rates, average daily egg mass, and eggshell quality of hens compared to the control (P