Effect of Red Mold Rice Supplements on Serum and Egg Yolk Cholesterol Levels of Laying Hens

Abstract

Monacolin K is a secondary metabolite of Monascus species and reduces cholesterol levels. This research focuses on the effect of adding red mold rice to hens' diet on cholesterol level in egg yolk and on cholesterol, triglyceride, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels in serum. Forty-eight Hy-line laying hens of 48 weeks of age were studied by dividing them into four groups. Except for the control group, the feed for three other groups contained 2.0, 5.0, and 8.0% red mold rice (monacolin K concentrations were 0.0145, 0.035, and 0.056%, respectively). The experiment lasted 6 weeks. During this period, egg weight and egg production were recorded every day, and cholesterol, triglyceride, HDL, and LDL in serum were measured weekly as well. The result showed that the cholesterol in eggs produced by experimental groups was lower than that of the control group (0%, 194.14 ± 8.30; 2%, 167.17 ± 4.34; 5%, 168.93 ± 9.38; 8%, 183.02 ± 7.63 mg/egg; p < 0.05), and the triglyceride (0%, 1494 ± 178; 2%, 1280 ± 174; 5%, 1189 ± 248; 8%, 1381 ± 218 mg/dL; p < 0.05) and LDL levels (0%, 36.81 ± 5.53; 2%, 32.25 ± 7.93; 5%, 30.06 ± 4.39; 8%, 28.81 ± 4.16 mg/dL; p < 0.05) were also significantly lowered in the experimental groups. However, the HDL level did not show significant change for either control or experimental groups (0%, 36.06 ± 3.96; 2%, 36.25 ± 5.39; 5%, 33.13 ± 3.68; 8%, 31.44 ± 4.29 mg/dL; p > 0.05). Besides, the addition of red mold rice also helps to inhibit production of malondialdehyde (MDA) in serum lipid oxidation (0%, 27.42 ± 0.53; 2%, 25.62 ± 0.76; 5%, 24.35 ± 0.59; 8%, 23.63 ± 0.48 μM; p < 0.05). Keywords: Monascus; monacolin K; red mold rice; cholesterol; egg yolk; laying hens