The Effects of Pre-incubation Storage on the Development of the Fertilised Bird Egg.
Fertilised quail eggs (Coturnix c. japonica) were stored in humid and dry atmospheres at 20°C for one week, wlth or without added CO2, and embryonic development during subsequent incubation for one week at 37.5°C was assessed by measuring both O2 consumption and embryonic mortality. O2 consumption for all viable eggs followed exponential pathways, and for eggs that died during incubation there was a sharp drop in this consumption to zero or near-zero. Environmental conditions that produced high CO2 Loss from the stored egg resulted in significantly increased levels of embryonic mortality compared to the non-stored eggs. High levels of CO2 in the storage environment (>=5% CO2-in-air) reduced the magnitude of this increase in mortality. In CO2-free air, atmospheric air and 2.5% CO2-in-air (dry conditions) embryonic mortality was found predominantly during the first 48 h of incubation. At higher levels of CO2 mortality occurred throughout the 7 days of incubation. The effect(s) of added C02 in the storage environment upon the pH and CO2 content of the egg during short-term storage was investigated. The pH of the yolk and albumen of non-stored eggs was lower than that measured for eggs stored in air. The addition of CO2 led to increased total CO2 content and increased acidity of the yolk compared to these measures recorded for eggs stored in air.Fleld trials on pheasant eggs (Phasianus colchicus) at a commercial gamebird farm investigated the effect of the loss of CO2 and H20 from the egg during storage (1-6 days) on embryo and chick mortality. Eggs were stored at 11.5-17.5°C and incubated at 37.5°C to hatching (25 days). Eggs that had been stored in plastic bags in air had both lower H20 loss and lower mortality compared to that for eggs stored in the open or in plastic containers with added CO2 , The mortality of stored pheasant eggs occurred predominantly in the first and last 6 days of incubation.