The effect of feeding di‐(2‐ethylhexyl) phthalate (DEHP) on the lipid metabolism of laying hens

Abstract Di‐(2‐ethylhexyl)phthalate (DEHP), a commonly used plasticizer, is now seen as an environmental pollutant. DEHP has been found to inhibit lipid and sterol synthesis in rats and mice. The effects of DEHP on various aspects of lipid metabolism were examined in chickens. White Leghorn laying hens were fed either a standard laying mash control diet (C) or the control diet containing 1% DEHP (DEHP) or 1% DEHP and 5% tallow (DEHP‐T) for 28 days. DEHP and DEHP‐T lowered feed consumption 10% but did not significantly affect body weight. After 3 weeks on the diets, egg production was 15–20% less in DEHP‐T than in C and DEHP hens. No differences were observed in egg weight, percent shell, white or yolk among the groups. DEHP and DEHP‐T did not alter egg lipid or egg cholesterol concentrations. DEHP and DEHP‐T lowered plasma lipid concentration about 20% and free and total cholesterol 20–30%. Liver weights increased, being 30, 34 and 39 g for C, DEHP and DEHP‐T hens, respectively, after 28 days. Total liver lipid and cholesterol increased 19% and 26% in DEHP hens and 54% and 79% in DEHP‐T hens when compared to controls. In contrast, the fat content of pectoralis major muscle decreased significantly in DEHP and DEHP‐T hens. These results, in showing that DEHP alters plasma and tissue cholesterol but not yolk cholesterol, demonstrate again that egg cholesterol is remarkably resistant to alteration by dietary means.