The Effects of Pre-incubation Storage on the Development of the Fertilised Bird Egg.

Abstract

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.