The effects of conjugated linoleic acids or an alpha-glucosidase inhibitor on tissue lipid concentrations and fatty acid composition of broiler chicks fed a low-protein diet

Abstract

The effects of dietary conjugated linoleic acid (CLA) and an alpha-glucosidase inhibitor--Bay g 5421--on tissue lipid concentrations and fatty acid composition were investigated in male broiler chicks fed a low-protein diet. The trial comprised six isoenergetic broiler diets. One diet (high-protein diet) was used as a control diet and contained 230 g crude protein per kilogram. The other five diets were low-protein diets (180 g crude protein/kg) without additional supplement, or supplemented with 20 or 40 g/kg of a CLA-enriched oil, or supplemented with 50 or 100 mg of Bay g 5421/kg. Broilers fed the low-protein diets had higher concentrations of triglycerides and cholesterol in the liver than broilers fed the high-protein diet. Broilers fed low-protein diets supplemented with CLA had a higher cholesterol concentration in plasma, lower hepatic triglyceride concentrations, higher relative concentrations of saturated fatty acids (SFA), and lower relative concentrations of monounsaturated fatty acids (MUFA) in lipids of liver, thigh muscle, and adipose than broilers fed low-protein diets without CLA supplement. Broilers fed the low-protein diets supplemented with Bay g 5421 had lower concentrations of triglycerides and cholesterol in the liver and lower concentrations of triglycerides in plasma than broilers fed the low-protein diet without supplementation. Moreover, broilers fed diets with Bay g 5421 had higher relative concentrations of polyunsaturated fatty acids and lower relative concentrations of MUFA in lipids of liver, muscle, and adipose tissue. The results show that supplementation of the low-protein diets with CLA and Bay g 5421 affected tissue lipid concentrations and fatty acid composition in broilers, which are of practical relevance with regards to meat quality.