Effects of external applications of fuel oil on hatchability of mallard eggs

An experiment was performed to determine the toxicity of oil to incubating eggs. Number 2 fuel oil, a mixture of 9 paraffin compounds, and propylene glycol were applied to the surface of artificially incubated mallard (Anas platyrhynchos) eggs. Seven groups of 50 eggs each were treated with 1, 5, 10, 20, and 50 μl of fuel oil, 50 μ1 of the paraffin mixture, and 50 μl of propylene glycol. Fifty untreated eggs served as a control. Microliter syringes were used to apply the liquid around the air cell end of the egg on the 8th day of incubation. Embryonic mortality was significantly greater (P ≤ 0.01) in all oil treated groups and the paraffin mixture group than in the control group. Most of the embryonic mortality for the oiled eggs occurred within 72 hours of treatment. Hatching and post-hatching (4 weeks) weights of the ducklings in all treatment groups were not significantly different (P > 0.01) from the control. Thus, the transfer of even small quantities of oil to the egg surface is sufficient to reduce hatchability.