Notes from Windward: #67



Testing out the Warm-e-rator's potential as an incubator

     About a month ago, we began toying with the idea of having an incubator, so that we can raise our own chickens, ducks, and maybe guinea hens. We have consistently gathered between 3-4 chicken eggs a day, which is more then we can eat, so we thought now would be a great time to experiment with expanding our flock. Only when we can replace our flocks onsite can we become self sufficient with our food supply.


     We decided to use an old refrigerator converted into a heating unit that we like to call a warm-e-rator. For a detailed description of its construction, Click Here. We initially used a 60 watt bulb for the heating unit and a coffee can filled with water for providing humidity. Given the cold temps outside, the maximum temperature that we were able to achieve was 94 degrees, and the maximum humidity was 25%.

     According to our research, the optimal temperature for chicken egg incubation is about 99.5 F°, and the optimal humidity levels are between 50% - 80%. We changed the light bulb to a 100 watt one, and added a second 75 watt bulb with an aluminum shade. That seemed to do the trick, because we now have a pretty consistent 100 F° temp.

     Since this was my first time incubating eggs, I wanted to gather as much information as possible about the process. I developed the following chart that helps us document when the eggs were gathered, if they were gathered still warm or already cold, and what temperature and humidity levels exist inside the incubator. With this data, we can perhaps figure out the causes of unsuccessful hatches.


     On November 21st, we introduced our first set of 4 eggs. On November 22nd, we introduced 3 more eggs, two were gathered cold and two were gathered warm. The temperature seemed to be holding at a steady 100.6 F°, but the humidity was still between 20- 30%, less then half of what it needs to be. Upon further research, I discovered that hanging a wet towel in the enclosure is one of the optimal ways to increase humidity. About 4 hours after doing that the levels doubled to 50%, not target levels, but close enough. The towel was also dry, so that indicated that it needs to be rewetted at least three times a day.

     Since November 21st, we have continually been adding eggs to the incubator, faithfully rotating the eggs anywhere from 3 -5 times a day. On November 27th we were without power for about 15 hours, in which time the incubator fell to below 32 F°. One of the eggs that had been placed inside of the incubator had cracked during this time, so I suspected that we lost any eggs that were inside the incubator at this time, but we kept them anyways. They should have hatched a few days ago, so I decided to candle them to see if they had started to develop.

     Candling, simply means shining a light through the egg. It's a simple way to discover if your egg has a developing embryo in it. I used a cardboard box with a hole, slightly smaller then the egg. One by one, I placed the eggs over the hole, and found out that compared to an egg gathered today, they all seemed to be at least partially developed. "If a cloudy spot or mass is observed, this can be assumed to be a growing embryo. If the contents of the egg allows light to pass uniformly through it (it's clear), assume that the egg is infertile. If an egg is candled at 7 days or older and is absolutely clear, it is dead or was never fertile." One of the eggs even showed a prominent air sack, which to me seemed enlarged. I then referenced a chart provided by the University of Nebraska [Click Here], and discovered that the air sac was the correct size for an egg at about the 18th day of incubation. I decided to put that egg back into the incubator for 3 more days. Perhaps we'll have a miracle chick!

     [Walt] We took the remainder of the eggs that had been chilled during the power outage, and broke them open to see how far along they'd gotten in the five days before the outage. The development was consistent with expectations.

     "[Monique] If humidity has been too low, the bubble will be oversized and the fluids under it will have dehydrated to the point where final development of the embryo will be retarded and the chick may become stuck to the shell when it pips." Click Here. Based on the simplicity of the procedure, it seems like a good idea to check the egg at anywhere between 3-7 days, which could end up saving time with the incubation process.

     We have a few more eggs that are due to hatch this month. Check back on the updates!
Notes From Windward - Index - Vol. 67