Received: 16-11-2021 / Accepted: 01-03-2022
This study was conducted to optimize the levels mixed herbal supplements in broilers diet for decreasing total cholesterol in blood plasma of chicken at 8 and 16 weeks of age. Six herbals supplements, garlic (Allium sativum), Chinese wedelia (Sphagneticola calendulacea), perilla (Perilla fruitescens var. crispa), turmeric (Curcuma longa), ginger (Zingiber officinale), and green tea (Camellia sinensis) were supplemented in the diet. A total of 126 male Dong Tao chickens were raised in animal farm of Vietnam National University of Agriculture from April 2021 to September 2021. This study was designed in two experiments: 1) Plackett-Burman matrix was designed to study the factors that affect total cholesterol content, 2) Response surface method (RSM) with central composite design (CCD) matrix was designed to optimize the levels mixed herbal supplements in diet. Garlic, turmeric, ginger, and green tea that have significantly contributed to total cholesterol in blood plasma was selected to design a matrix for modeling optimal point. The result of response surface method (RSM) with central composite design (CCD) showed the minimum value of total cholesterol 2.80 mmol/l (8 weeks of age) and 2.70 mmol/l (16 weeks of age) with level supplement of garlic (0.833 and 0.882 g/kg), turmeric (0.420 and 0.441 g/kg), ginger (1.411 and 5.400 g/kg), and green tea (5.221 and 6.215 g/kg), respectively. The lowest value of total cholesterol in the practical model was 2.80 mmol/l and 2.70 mmol/l.
