RESUMO
BACKGROUND: Gracilariopsis persica (Gp) is one of the most abundant red algae distributed in the Persian Gulf, containing various bioactive components with hypolipedimic, hypoglycemic and antioxidant properties. Therefore using laying quails as a model we aimed to investigate the effect of dietary Gp on body weight, feed conversion, estradiol, progesterone, calcium and lipid levels in serum, as well as the high-density:low-density lipoprotein (HDL:LDL) ratio. Yolk cholesterol and yolk lipid oxidation were also evaluated. To accomplish this, diets containing 0, 10, 30 and 50 g kg(-1) Gp were fed to 5-week-old laying quails for 12 weeks. RESULTS: Our data revealed that Gp had no effect on body weight, feed conversion, triglycerides and estradiol levels of serum. Dietary Gp decreased the serum and yolk cholesterol in a dose-dependent manner. In addition, the sera progesterone and calcium levels and HDL:LDL ratios were increased by feeding diets containing 50 g kg(-1) Gp. Our results relating to yolk lipid oxidation showed that malondialdehyde content was decreased in Gp-fed laying quails. CONCLUSIONS: The results of the present study demonstrate that not only serum and egg yolk cholesterol levels, but also susceptibility of yolk lipids to oxidation, can be decreased by feeding Gp to laying quails.
