Influence of culture filtrate ofTrichoderma viride and barley on lipid metabolism of laying hens

Abstract

The suppression of hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase and cholesterol 7 α-hydroxylase, previously noted in studies of the influences of barley and the filtrate ofTrichoderma viride culture (CF) on cholesterol metabolism in sexually immature birds, is shown in sexually mature birds. Barley, CF or both were fed in one study from the day of hatching, in another during the period of sexual maturation and, in a third study, CF was fed to mature layers. CF suppressed HMG CoA reductase by 30–50% and cholesterol 7 α-hydroxylase by 32–45% when added to the control diet. In birds fed barley rather than corn, the respective activities were 25–36% and 24–31% lower. These effects were expressed in the lowering of plasma cholesterol by 11–36%. Lipogenic activity based on the assays of 4 enzymes was increased 2–3 times by the treatments and plasma triglyceride elevated by 12–86%. The start of egg production by birds fed CF preceded the controls by 17 days. Birds fed barley trailed controls by 11–14 days. CF countered the barley-conditioned delay. Egg yolk cholesterol concentrations were lowered by both treatments. Eggs produced by hens fed barley were lower in weight; CF increased egg and yolk weights. Tissues from birds fed CF or barley for up to 30 weeks appeared to be normal.