Effects of feeding thymol and isoeugenol on plasma triglycerides and cholesterol levels in japanese quail

Abstract

Dietary supplementation can be considered one of the main strategies to include new additives with beneficial effectsinto animal products. Thymol supplementation has shown to improve oxidative stability of eggs and meat during storageand also to increase the relative composition of polyunsaturated fatty acids. Feed supplementation with isoeugenol hasshown to increase hatching success. The present study evaluates supplementation with thymol and isoeugenol on plasmalipid profile in Japanese quail. At 4 weeks of age, 48 males and 96 females were housed in groups of 1 male and 2females and assigned during 10 weeks to 1 of 4 diet treatments: vehicle or 400 mgkg-1 of butylated-hydroxytoluene(controls), and 400 mg kg-1 of thymol or isoeugenol. Body weight, growth rate, and egg production were determined. At14 weeks of age, plasma lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides) were alsodetermined. Results demonstrated that supplementation with thymol and isoeugenol increased female triglyceridescompared to males and to control females. No triglyceride changes were induced by butylated-hydroxytoluene. Bodyweight, growth rate and egg production were not affected by dietary treatments. The increased plasma triglyceridesobserved in female birds may have biological relevance to better sustain the metabolic needs during laying period. Theseresults contribute to show the potential usefulness of these essential oil main components as natural feed supplementalternatives for poultry.