Dry Incubation

By Bill Worrell

As a student of poultry at age 14, I became fascinated with the breeding and hatching of eggs. Even when I only raised mixed breed chickens and ducks I was always trying to find ways to incubate eggs. I started my poultry hobby with a few Araucanas and a few White Jersey Giant hens. My challenge became to find a way to get them to become broody. I never did. So I started trying to figure out how to make an incubator. I tried everything you can think of and nothing seemed to work. A few months later an old friend of mine told me he had an old redwood incubator that hadn't been used for 15 years or longer. I asked what he wanted for it. He replied that he'd like to have my car stereo. So I went out to the car and took it out and swapped it even. Man what a deal I thought. This thing was huge to me. It was 4 feet long, 2 feet wide and 3 feet tall. It had no egg turner and it had a water pan that had more holes in it than a sifter. I brought it home on my dad's old pick-up truck and cleaned it up. I plugged it in and decided it would probably need some work before I trusted it enough to leave it alone, much less hatch in it. Well, to make a long story short, I did fix it up and got it working. Then placed it in my bedroom, much to my parents' dismay. Man I was in the hatchery business.

I hatched every egg I could find. Tried everything imaginable from ducks to geese, from chickens to guineas, from quail to wild turkeys. I had some success but mostly failure. I had no understanding of how a bird develops in the egg, knew nothing about humidity, heck I didn't even know about turning eggs in the incubator. I just knew it was fun to see baby chicks come out of the shell. Still today it is what I love most about the hobby.

The next year I added my first foam Hova-Bator from GQF. Reading the directions I found out for the first time about how to add water and the importance of turning eggs. For the first time I had a thermometer and I learned what a thermostat wafer was. Boy was I excited.

I started to incubate in conventional ways of adding water and turning the eggs, keeping the temperature at 99.5 degrees, and candling with a flashlight. I had good success but never hatched better than 60% and that was on rare occasions. Still I thought that was great. I had a few friends bring their eggs to me and ask me to hatch them. So I started a little enterprise at age 15 doing custom hatching for $1.00 per dozen. That first year with my new incubator and my old redwood incubator I incubated over 750 eggs. But all along I never realized how these hatcheries got 90-95% hatches. That was until a few years later.

I met an older gentleman who asked me how I was hatching my eggs. I told him this story and explained that I could never get the hatch rate above 60%. He then replied, "Have you ever tried incubating dry?" I said I hadn't. Then he explained what I am about to tell you. He said, "Bill, you need to stop adding water to your incubator. Those foam incubators are real bad to drown the chicks inside the egg." I said to myself, yeah right. That doesn't sound like any way of incubating I ever heard of. But I listened. This man changed my incubation practices forever. I took the info he gave me and experimented with it. And soon my hatch rate went to 70%, then 80%, then 90% and has even been 100% on several occasions. I now use it exclusively in my foam incubators. I will add just a teaspoon of water on occasions when the humidity is real low here, especially in the winter time. In our new 1202's we will add 1/4 inch of water in the pan but we cover half of the pan with foil to cut back the water surface and we leave the vents open all the way, even the bottom one's. We have found that the humidity will stay around 40% inside the 1202's when we do this. Then about every 3-4 days we add another 1/4 inch of water. The water wont last for 4 days but we like to dry the bator down totally for about 12-18 hours before we add any more water. When the 1202 is out of water it will still register 25% humidity or there abouts. We have only had 1202's for a short time so we are still experimenting with them a bit.

I now incubate fewer eggs each year and have more chicks that I did when I was incubating several hundred each year for myself, though most of what I hatch today is for other people. At one time I was hatching over 1,000 eggs per month and sometimes 1,000 per week for other people. So this is not theory. I still use it today and will never go back. Here is how it works:

First, you have to remember a few things. An egg must lose approximately 11% to 14% of its weight during the incubation cycle. That is, it has to have some evaporation of the contents of the egg itself in order for the chick to have room inside of the egg to develop and still have room to turn in the egg so it can spin around and pip the shell. Where most folks go wrong is they add water to often or they add too much to the incubator and cause the humidity to increase to levels that slow or stop the evaporation process. This causes the chick to grow too large inside the egg. The chick will pip the shell on day 21 and never go any farther. Or they wont pip at all because they puncture the internal membrane of the egg and there they are met with a gush of water, causing them to drown. Have you ever wondered why this happens? I sure did.

Second, the closer you can get to the proper temperature and keep it there the better. That is, keep your incubator in a room that the temperature doesn't fluctuate drastically. My old redwood incubator will hold heat in a room where the temp doesn't fluctuate more than 20 degrees. My Hova-Bators aren't near that good. Even our new 1202's will not hold temperature real well if the room changes temperature often. They need to be in an area where the temp is close to the same within 10 degrees or so. I recommend that placement be in a room that doesn't get direct sunlight in any windows. If you have central air or heat, you can leave the doors open and the vents open. This will make the whole house one constant temp.

Lastly, start with good eggs. I never set odd shaped eggs or eggs that are too large or too small. They must have good shell quality and be from healthy birds. I recommend you feed a well balanced diet to your birds including Kelp, and D.E. as a de-wormer. I also recommend that you supply dried garlic to help with overall health and to boost the immune system. I also would advise you to gather eggs often in extreme weather and store them in an environment that is around 40-50% humidity and also the temp is below 70 degrees.

And finally, set your eggs each week or 10 days maximum. I usually set mine every week on Sunday's or Wednesday's. We think that if Sunday or Wednesday rolls around and we don't have to stop eggs from turning or eggs aren't hatching or being put into the incubator, we don't have anything to do. This is what works for us.

Now that you have your room set up, I would plug in the incubator and add no water. Allow the incubator to stabilize for a minimum of 48 hours to be sure it is at 99.5 for forced air (fan installed) or 101 for still air (no fan). While it is stabilizing, get a room hygrometer (instrument that measures humidity) and place it in the room. Bring the humidity level in the room up to between 50%-75% preferably 50%. If you live in a humid environment, you may actually need to dehumidify your room. But nevertheless, if you keep the humidity at 50% or close to it, you will do great. By controlling the room humidity, you can be more precise with your moisture in the incubator especially the foam incubator's. Since your incubator gets its air from the room, it will have some humidity. You may on the 1202's, have to add a small amount of water as they tend to run a little drier than some incubators. If the humidity in the room drops to 40% don't get concerned. The eggs themselves will supply some of the humidity needed inside the foam incubator's. They will also supply some humidity in the 1202's but not near as much with 1 tray full of eggs as they will if the 1202 is completely full. Higher humidity is worse that lower humidity as higher humidity hinders evaporation.

By the way, if you are using a foam incubator, make sure the red plugs are not in the vent holes. I have been trying it both ways for a long time and I have recently came to the conclusion that if you take the vent plugs out, the room humidity will work a little better inside the incubator. In the 1202's we leave all the vents open, including the top and bottom vents.

After 48 hours of stable temps in the incubator and stable humidity in the room, you are ready to place eggs in the incubator. I use turners as they allow me to incubate the eggs without having to open it up 2 or 3 times a day. Place your eggs in a turner with the big end up. Close the incubator and forget about it for 7 days.

For foam incubators: On day 7, open the incubator and candle your eggs with a good candler. Throw away all the clear eggs as they will soon rot and could explode inside the incubator causing loss of the healthy eggs. Be very gentle when handling these eggs, as the tiny embryos are very fragile at this stage in incubation. After the first candling, close the incubator and forget it for another 7 days. Also while you have the incubator opened, check the humidity inside the incubator. In foam incubators, add a teaspoon or two of water if the humidity is real low. Low being 25%.

For 1202's: Open the bator every 4 days or so and add 1/4 inch of water to the pan. I have found that small bantam eggs do much better with a little moisture so if we have bantam eggs in the incubator, we make sure the humidity stays at or about 40%. We always let our 1202's dry down for about 12-18 hours before adding more water. We think this is the best method according to our hatches. On large fowl eggs we have found that the lower humidity levels, say 25% are fine for them for 24-36 hours.

For foam Incubators: On day 14, open the incubator and candle the eggs again with your candler. Look for a real dark mass inside the egg and a small clear cell at the big end of the egg. This is the air cell. This is where the chick pokes through first to get its first breath of air. If you were using the conventional means of incubation and had the humidity too high for these 14 days, your chick might encounter a good amount of water here. This could and often does drown your new chick before it even has a chance to pip the shell. We recommend that you watch the air cells real close. If too large or growing to fast, you need just a little humidity. If they are no bigger than when you started, then you need to decrease the humidity. If you see any eggs with large amounts of clear spots in them, compare them to the others and if they are very different, discard the eggs that have big clear patches.
These embryos may have died for various reasons while developing. After you candle them, put the lid back on the incubator and forget about it until day 18.

For 1202's: You should keep and eye on the humidity in these every 4 days or so and candle on the 7th, 14th and 18th days. Watch the air cells closely as they are the best indicator of too dry or too wet.

For foam incubators: On day 18, open the incubator and add a very small amount of water to one of the water channels in the bottom of the incubator. If you notice the humidity in the incubator is above 65% add only a tablespoon of water or two. If your incubator humidity is below 65% add about ½ of the channel full of water. Remove the eggs from the turner and lay them flat on their sides. Try to allow a little room between them. Then close the incubator. Place the vent plug that doesn't have the metal inside it back into the bator. You know the one that opens directly into the inside of the bator? Leave the one that has the metal inside of it out of the hole for now. Now, follow the next direction very closely.

DO NOT, UNDER ANY CIRCUMSTANCES, OPEN THE INCUBATOR FOR 5 FULL DAYS.

Hate to shout at you but this last 5 days will make or break your hatch. I get a little aggravated when people will go through all the previous steps and then it gets down to the moment, and they can't resist opening the incubator. Every time you open the incubator, you release valuable moisture out of the incubator and allow dry air in. This is what causes chicks to stick to their shell membranes. All you will have to do is lose a few chicks to this and you will change your habits. This means don't open the incubator until day 23. I do recommend that on day 20, you place the last vent plug back into the bator. This will allow the moisture to stay inside the bator for the last day and while the chicks are hatching. When the first chick hatches, you will notice that the windows in the foam incubators will form a lot of condensation of them. If this condensation is covering nearly the entire window, remove the vent plug that covers the hole with the metal in it and turn it upside down and place it directly over the hole you just took it out of. This will allow a little bit of moisture to escape. In an hour or so, you will be able to see inside the window again. If it doesn't dry the window a little, then slide it away from the hole just a tiny bit. Then check it again in about 1 hour.

On day 23 the chicks will be ready to take out of the incubator and placed in the brooder area. Make sure you have water ready and chick starter in low feeders ready for them in the brooder box. When you take a chick out of the incubator, dunk his beak in the water and make sure he gets a drink. Do this for all of them.

Make sure they have a source of warmth, (i.e. a heat lamp, light bulb, brooder, etc).

I recommend you have 2 incubators (one for an incubator and one for a hatcher). This will help if you have several different hatch dates in one incubator. On day 18 place the eggs over into the hatcher incubator. Then add water and you're good to go.

We always have hatching incubators and incubating incubators. We fire up our old redwood incubator and then keep it at the proper humidity. Since we hatch weekly, we need the hatcher to be ready at all times. This also keeps the incubating incubators clean because no egg or chick mess is ever in there. We like to hatch at about 65-70% humidity in the redwood.

A final thought: We have used this method to hatch chickens for a long time here at Briarpatch. We have not tried it on water fowl, but we have used it on quail, turkeys, guineas and other type of dry land fowl with excellent success. We cannot guarantee that this method will work for you. Heck we don't even know how you operate your incubator's or what environment you use them in. Your climate will play an important role in how you modify this to meet your hatching needs. We recommend that you not be afraid to experiment a little with eggs that you can spare to learn how your incubator performs and how you perform. We get numerous emails during hatching season telling us they use this method with great success. We also get some that have no success. Before you incubate eggs that really mean something to you, try some eggs that don't mean so much to you and get them down pat before you jump in and start incubating eggs that you paid a lot of money for. We only want to help you succeed at incubation.

You may want to visit our homemade incubators section or ask questions about incubating your eggs in our chicken forum.