Effect of oxygen and maternal dietary iodine on embryonic carbohydrate metabolism and hatchability of turkey eggs.

Abstract

Fertile turkey eggs were produced by hens fed supplemental iodine to decrease eggshell conductance. The eggs were then incubated in an oxygen-enriched environment during Days 25 and 26 of incubation to test the hypothesis that maternal dietary iodine has separate effects on the eggshell permeability and the developing embryo. Oxygen supplementation improved hatchability regardless of dietary iodine treatment, suggesting that oxygen availability may limit hatching of eggs with normal gas conductance. Oxygen and dietary iodine did not affect body weight but interacted prior to pipping to affect embryonic liver and heart glycogen. Dietary iodine increased liver glycogen at internal pipping. The effects of oxygen on embryos, which were correlated directly with hatchability, were increased liver growth prior to pipping and increased heart weight at external pipping and posthatching. It was concluded that supplementing oxygen to incubating turkey eggs may improve hatchability by increasing liver and heart growth. Dietary iodine played only a minor or modulating role in assisting embryos to survive.