Variation in plasma cholesterol concentration over time in the domestic fowl

1. Variations in the concentration of plasma cholesterol available to the developing oocyte over a three week period in Gallus domesticus are described. 2. There are small changes in concentration between weeks for individual birds, but no changes between consecutive days within weeks or times within days. 3. It is recommended that future attempts to assess the relationship between variation in blood and yolk cholesterol concentrations estimate blood cholesterol concentration from two samples taken a week apart.