Over the weekend, I candled and weighed all our eggs so I wanted to share how I do that and what I found out. Here are my printable record sheets and candling/weighing instructions, if you need a copy.
I always expect to lose lots of eggs at the first candling because not all the eggs will be fertile. By the 7th day, you should be able to see development in fertile eggs. You should see veining or even the small chick. You might even see movement if you are very careful. Here is a great site to reference when you are learning what to look for.
I’ve found that, for me, the bathroom is the best place to candle eggs. There are no windows, so when I turn the lights out it is perfectly dark. I put a space heater in there and turn the shower on for a minute so that it’s nice and warm and humid. That part isn’t really necessary if you have a small incubator and are doing a couple dozen eggs. Cooling down once a week for half an hour or so won’t hurt anything. But since I do 8-9 dozen at a time and tend to like to take my time, I don’t want the eggs to get too cool.
When I candled, I found that I had quite a few infertile eggs, just as I expected. I lost nine Barred Rocks. When you include the egg I broke the first day, that leaves me 26 that appear to be developing nicely. Two of them have very weak looking shells, so I’m concerned, but I saw movement in both eggs, so I am not going to discard them.
Four of the “Surprise” Good Shepherd eggs were infertile. I don’t think I explained what these “surprise” eggs are. When we went to Good Shepherd, I wanted to get some Colombian Wyandottes, but he didn’t have them separated. So he pulled out a dozen of what he thought were probably Colombians, and gave them to us at a big discount because they may be one of his other breeds. He doesn’t have any breeds I don’t like, so it will be exciting to see what we get.
I’d mentioned on Facebook that I had concerns about the fertility of my Rhode Island Whites, and I was right to be concerned. Eleven of the thirteen Rhode Island Whites were infertile.
Only two out of fourteen of my friend Delores’s eggs were infertile. That is great!
Finally, my Easter Eggers have me stumped. The eggs seem very thick and hard to see into. But what I can see is a much bigger shadow than I would expect for a seven day chick. They really look to me like fourteen day chicks, which doesn’t make sense at all. I gathered these eggs and stored them for only a few days in a cool place. There is no way they can be as developed as they appear. So it will be a fun mystery to see if some crazy monster chicks come out of these eggs.
After I crossed the 24 obviously infertile eggs off my record sheets, I weighed each egg individually and recorded those weights. Then I calculated the percentage of weight lost to see how my humidity had been. Humidity is not a set in stone number. The goal of regulating humidity is to have the “right” amount of moisture evaporate out of the egg by hatch day. If too much humidity evaporates the chick could be too dry, which can cause smaller, weaker chicks. If not enough humidity evaporates the chick could be bloated or even drown because it’s air sack isn’t sufficient to allow it to breath as it’s hatching.
Many people hatch chicks without weighing and are successful. Others weigh eggs all together or by the dozen rather than individually. My problem with that is that I don’t know how to handle the discarded eggs. To me it seems best to know the weight of that individual egg, so I can remove it from the calculation.
That calculation goes like this (warning – warning – the blogger you are now reading is a total math nerd – if you do not wish to deal with math, skip the following paragraph – warning – warning)
X = Total of Day 1 weights (with all lost/infertile eggs removed from the list).
Y = Total of Day 7 weights
Y ÷ X x 100 = % of weight remaining
Just as an example, I will use on dozen of my Barred Rocks. The weights on Day 1 totalled 26.13 ounces. On Day 7 I lost three of those eggs so I removed their Day 1 weights from that total (26.13 – 2.36 – 2.08 – 2.01 = 19.68). The remaining eggs on Day 7 totalled 18.81 ounces. 18.81 ÷ 19.68 x 100 = 95.6%. The goal was 96%, so my humidity has been pretty close to perfect.
The last thing I did was to break open all those discarded eggs. I do this just for my own educational purposes. I like to look and see if I can see any evidence of fertility. If the chick just stopped developing very early or if it was never fertile to begin with.
I’m getting excited. New chicks just before Easter will be fun.