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Day 11 weighing eggs??

Discussion in 'Incubating & Hatching Eggs' started by Chickengirl1304, Jan 25, 2013.

  1. Chickengirl1304

    Chickengirl1304 Songster

    May 5, 2012
    I'm dry incubating and didn't weigh the eggs in the beginning :( can I weigh them now? Or do I need something to compare it to to move forward? It's day 11

  2. Sally Sunshine

    Sally Sunshine Cattywampus Angel <straightens Halo> Premium Member Project Manager

    Aug 23, 2012
    My Coop
    you must weigh from start or track air cells.... but your still ok... do the observing method!!


    Understanding the Air Cell

    The average chicken egg has thousands of pores running through the shell allowing the embryo to exchange oxygen and carbon dioxide. Water is also lost through these pores. Soon after an egg is laid, a small air bubble or “air cell” forms in the large end of the egg from this water loss. Humidity levels in the incubator determine moisture evaporation during the 21 days of incubation and hatching. The air cell is crucial for the chick to break out of the egg shell at the end of the incubation period. The chick can drown if the air cell is too small or the chick may be retarded in growth if the air cell is too large. This is why maintaining the proper humidity is crucial. Slightly lower humidity levels are more likely to be less disastrous than slightly higher humidity levels.


    MARKING and OBSERVING the size of the air cell is a way of checking for correct weight loss of the egg and is commonly used. However, this can be inaccurate due to the different, types, shapes, and ages of eggs. The protrusion of the embryo into the air cell also may effect observations. Again, it is the most common method for non-commercial hatchers. With experience you can adjust your humidity as needed by visual inspection of air cells. However, Weighing is the MOST accurate.

    If the incubation humidity is too low (very dry conditions), the air sac will be larger than normal and the humidity in the incubator should be increased to reduce the rate of water loss. If the air space is smaller than normal then the opposite applies.

    Track the air sac with pencil tracings when you candle,
    On the 7, 14 & 18th days


    Chicken eggs need to lose 13% moisture over 21 days. Weigh all the eggs on the first day, before you put them in the incubator and weigh again days 10, 14 & 18.
    Several formulas can be used to determine the rate of weight loss or overall per cent weight loss and to correct the humidity if the values are off. For accuracy, a digital scale should be used which can weigh in grams. Don't forget to subtract the weight of the container holding the eggs from the total weight when calculating the average egg weight. If you use a rack to incubate your eggs it is best to weigh the entire rack instead of each egg to get an average. If you are incubating SHIPPED eggs upright in a carton you will also weigh the entire carton so that the eggs are not disturbed.

    For formulas used to determine the weight loss please refer to
    Weight Loss Determinations:
    Hatching Guide:

    Note: Kitchen scales work great. The WeighMax Pocket Mini CD Digital Scale below works great if you weigh individual eggs. I pasted an egg carton cup firmly to hold the eggs. Be extremely careful not to tip your scale and crack your eggs!


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