Schipperkesue wrote:What is the temperature on your Brinsea? I found their built display to read a little high.. I have three spot checks and all give me the same temp in the incubator, all are a little high.
I have a theory about these wonderful new automated machines of ours. They keep the temperature and humidity so steady. Maybe too steady. For goodness sake, you never even have to open the door. The eggs never cool or loose humidity. If your temp and humidity are a little off, it stays that way for the whole incubation period. No variations when the door opens.
I had better results with feet after two events occurred. One was my humidity pump broke and I had to open the machine to fill by hand. The other was when I found the digital read out was too high. I calibrated the Brinsea, plus I lowered the temperature again .3 degrees to correspond with what I had been reading about higher temperatures.
I would like to add another factor that I only came across when I was researching our leg problems. Modern incubation techniques have standard temps & humidity which work with many of today's breeds. Now these temps & humidity sets work fine for many breeds and many of us, we follow them and have great hatches.
However, there are a few studies that suggest heritage breeds may not do as well using modern sets. They many need slight adjustments during incubation and lockdown in order for them to both develope properly and to hatch successfully.
I noticed it when I had set houdan and polish eggs. I used the sets I normally used for my polish. When it came to hatching, my polish hatched with no problems. My houdans were a different story. The ones that hatched had leg issues, most of them splayed. Most of my houdan eggs failed to hatch. When I autopsied them, they were devloped to about Day 18/19. All had egg sags attached and were nowhere ready to hatch. When I raised my humidity up for lockdown, that increased humidity caused the houdan chicks to drown inside their shells.
For my hatch problems, I looked into what commercial hatcheries do. I came across a company called Pas Reform which specialize in hatchery technology. Their web site is full of a lot of interesting articles which I found helpful. Yes it may be research for commercial production but many of the principles can be applied to someone with a Hovabator. For instance, as the embryo develops and the chick grows, it will begin to generate its own heat inside the egg. This can be recorded using an infor-red baby thermometer. When you take your eggs out to candle, use the baby thermometer at the mid section of the egg to take its temp. Do this with a cross section of your eggs. Say on a set of 24 eggs, quickly scan 3 or 4 that are on different areas of your tray. As the embryo develops, the egg temp should continue to go up. As the egg gets closer to hatching, the incubation temp should be decreased.
I used the info that Sue discovered in regards to tweeking the temps and humidity. I began to keep hatch records, everyday recording the temp & humidity. Using a general guideline I got for broiler eggs, I set my temps & humidity and using the information I got from Pas Reform, I tweaked the sets at what are called Key Days during embryo development.
Day 0 to Day 12 Humidity is set and not fiddled with.
Day 0 to Day 3 Vents are kept closed to help with early embyronic develpment.
Starting at Day 3, Temp is slightly decreased by .1 to .2 every second to third day. Vent is opened to 10%.
Starting at Day 12, Humidity begins to play a part and can be set at 50% Venting should be at 50% to allow for air. Temp is a full degree less than when incubation was started: Day 0 set was 100.4 F/38c and at Day 12, 99.2F/37.3c.
By the time you reach Day 18, temp can be a full 2 degree less, 98F. The egg temp itself, should be about 101.3-101.5F. Vent should be open to allow for air.
Humidity at Day 18 thru to Day 22 becomes your make it or break it. Many incubation guides recommend putting humidity up from 50% to 65-70% for lockdown. I found that this is where I was killing many of my houdan chicks. The sudden humidity jump caused my chicks to drown inside their shell. As well, putting the humidity up too late, causes them to dry out. The solution was found in how commercial hatcheries work. Humidty is gradually raised to what is refered to as the Hatch Window: an 8 hour time in which commercial chicks should pip & hatch out.
What I found out by keeping records, by increasing humidity gradually from Day 18 to Day 21, I had better hatches with my Houdans. Day 18 I increased my humidity from 50 to only 55%. Then an increase to 60%. I only hit the humidity up to 65% when I saw my first pips. Within that window, my eggs pipped & hatched. I still had losses by they were much less. The houdans that hatched had no leg problems and were able to stand immediately, something my previous hudan chicks could not do. Also I had fewer flip over chicks: chicks that flip onto their back and can't right themselves.
It took me 5 full incubations to get a recipe to hatch out my houdans. I say my houdans as Sue has her way to hatch the breed out that is successful. Our principles are the same though: decrease temps up to Day 18 and then increase humidity but not to the recommeded 65-70% that most guides suggest. Instead cut the humidity down and gradually increase it.
Last point, I recommeded not incubating different breeds together. If you are having a problem with a specific breed, incubate that breed alone until you get your sets right for that breed.
