- Research in our laboratory focuses on assessing the cholesterol requirement of the developing chicken embryo. We use an electrosurgical instrument to produce a canal from the exterior of the egg to the yolk on day 3 of incubation. The yolk is displaced with a physiological solution of electrolytes, glucose and antibiotics on day 4, and then replaced with cholesterol-reduced egg yolk on day 5. Typically, we have incubated eggs for 20 days, one day before the expected time of hatching. It appears (see impact statement) that less than half of the cholesterol normally present in eggs is required for embryos to 20 days of incubation. However, the concentration of cholesterol in liver, but not in brain, at 20 days is significantly reduced by the use of cholesterol-reduced egg yolk. Current research focuses on the effect of cholesterol-reduced yolk on chicks after 20 days of incubation, at the stages of hatching and early post-hatch growth and development.