Wednesday, January 13, 2010

More on Incubation – What We Did Wrong

I researched incubation of eggs and decided that, although the maintenance temperature for our Bourke parakeet eggs was okay, when they started piping they required more humidity than what was provided. This is likely why they were unable to hatch. I wish I’d acquired this information sooner. However, in the future if fertile eggs are laid on the bottom of a cage, or abandoned, this knowledge will be put to good use!

The average incubation period for parakeet eggs is 19 days from the day the egg is laid. However, 18-21 days is also common. Temperature is very important during incubation. Temperature can vary between the top and bottom of an egg, so turning them about five times every 24 hours is necessary. Overnight can be eliminated, but be sure to turn them late and early again the next morning. Never leave them with the small end up. Eggs should either be placed large end up or on their side. Turn eggs on a 90-degree plane as gently as possible. If they are not turned regularly, chicks may stick to the inside of their shells. Turning should continue until one or two days prior to hatching or until the eggs are piping.

For the eggs’ first week, the temperature should be 101 Degrees Fahrenheit, then 102 Degrees F for the second week, and 103 Degrees F until hatching. If you’re fortunate enough to have a large commercial forced-air incubator where turning is not required, the temperature can be kept at 99-100o F. However, most of us do not have access to that state-of-the-art equipment.

Eggs lose water while being incubated, so humidity is key. For optimum growth, a relative humidity of 60 percent should be maintained until eggs begin to pip. Then relative humidity should be raised to 70 percent. A pan of water is imperative; however, it may not be enough. In such instances, suspending a piece of cloth from the water will provide wick action.

To gauge relative humidity, wrap a wet cotton cloth around the bulb of a thermometer and suspend it in the hatching chamber. With evaporation, the “wet” bulb thermometer will have a temperature lower than that of a dry bulb thermometer in the same chamber.

Ventilation is important too. The older the egg, or the larger number of eggs present, the more oxygen will be used by the developing embryos. Also, more carbon dioxide is released. Ventilation capability must be incorporated in the incubator area.

Testing for fertile, viable eggs: When a hen suddenly died, I removed the eggs from her nest box, expecting the embryos to be dead too. However, I gently put them in a bowl of warm water. One sank and the others floated. I assumed the floaters were no good and discarded them. The one that sank went under another hen and ultimately hatched.

Newly laid eggs will display red veins if they’re fertile. These should appear very soon, but I’d give the eggs a few days before discarding any. If, after a few days, you shine a flashlight through the shell and all you see is clear liquid and a yellow yolk, the eggs weren’t fertilized. I tend to let my hens sit on them anyway, until the hen decides to abandon them, but that’s a personal choice. Maybe they’d go back and lay good eggs sooner if the infertile eggs were removed.

Incubating eggs may seem complicated, but consider the fact that the Chinese developed artificial incubation as early as 246 B.C. And, in the year 400 B.C. Aristotle wrote about Egyptians placing eggs in dung heaps and successfully incubating them. Personally, I’d rather use a light bulb and thermometers.

Happy incubating and good luck!


G. Lewis said...

Surprisingly, this hen has had three clutches since this was written. All of her eggs were fertile and the babies grew until ready to hatch. However, NONE hatched. Apparently, there is something wrong with her or the genetics of the pair. So, this incubator may not have had a problem after all!

G. Lewis said...

Later comments suggested she might not be getting enough Vitamin D ... something we intend to try.