Difference between revisions of "Egg Incubation Physiology - Anatomy & Physiology"
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== Heat Transfer to the Egg == | == Heat Transfer to the Egg == | ||
| − | + | * Transfer of heat from the body to the egg is the most important contribution of the incubating adult to incubation. | |
| + | * Most birds develop a seasonal bare patch of skin known as the 'brood patch' on part of the thorax and abdomen. | ||
| + | ** 'Brood patch' is in direct contact with the egg to permit a greater heat transfer than if there were feathers between them. | ||
| + | * At the same time, there is an increase in the size and number of blood vessels in the bare skin. | ||
| + | ** Serves to increase heat transfer, as hot blood runs closer to the surface. | ||
| + | * Adult can adjust the rate of heat transfer by: | ||
| + | ** Standing or leaving the egg. | ||
| + | ** The closeness with which the 'brood patch' is applied to the egg. | ||
| + | ** Responding physiologically to the temperature of the egg, thus increasing or decreasing metabolic heat production. | ||
| + | * 'Brood patch temperature is 34.9-42.4 | ||
| + | |||
== Development of Physiological Functions == | == Development of Physiological Functions == | ||
Revision as of 11:56, 22 July 2008
Changes in Composition of the Egg during Incubation
- As the embryo grows within the egg, the composition of the egg changes.
- Both yolk and albumin diminish.
- Yolk providing energy for growth and maintenance of the embryo.
- Albumin providing protein for the embryo and giving up water, which is lost through pores in the shell.
- Water is produced when yolk fat is oxidised.
- Water lost from the egg is replaced by air, creating the 'air cell' at the blunt end of the egg.
- Embryo punctures the chrioallantoic and internal shell membrane.
- Able to begin pulmonary ventilation, rebreathing the 'air cell' gas.
- Transition from diffusive respiration through the chorioallantois to breathing through the lungs.
Heat Transfer to the Egg
- Transfer of heat from the body to the egg is the most important contribution of the incubating adult to incubation.
- Most birds develop a seasonal bare patch of skin known as the 'brood patch' on part of the thorax and abdomen.
- 'Brood patch' is in direct contact with the egg to permit a greater heat transfer than if there were feathers between them.
- At the same time, there is an increase in the size and number of blood vessels in the bare skin.
- Serves to increase heat transfer, as hot blood runs closer to the surface.
- Adult can adjust the rate of heat transfer by:
- Standing or leaving the egg.
- The closeness with which the 'brood patch' is applied to the egg.
- Responding physiologically to the temperature of the egg, thus increasing or decreasing metabolic heat production.
- 'Brood patch temperature is 34.9-42.4