>>12476046https://reducing-suffering.org/how-much-direct-suffering-is-caused-by-various-animal-foods/Eggs
['Egg laying hens (chickens) in a factory farm battery cage.' By Compassion Over Killing [CC-BY-SA-3.0 (
http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Animal_Abuse_Battery_Cage_01.jpg] Wepruk (n.d.): "Hens generally [begin] laying at 18 to 20 weeks of age. Normally they are considered spent between 71 and 72 [average = 71.5] weeks of age. Therefore, laying hens have a production lifespan of approximately one year. In that year, hens lay an average of 288 eggs each." (This doesn't count forced molting, which can extend the productive lifetime of hens.) A lifespan of 71.5 weeks is 501 days.
USDA (2017, "Chickens and Eggs") reports (p. 7) a total of 2,480 "Eggs per 100 layers during March" of 2017 for "Table egg type" hens (i.e., hens laying eggs to eat rather than for hatching). With 31 days in March, that implies 2,480 / (100 * 31) = 0.800 eggs per hen per day. Over a year of laying, that would be 365 * 0.800 = 292 eggs, which basically matches the 288 number from the Wepruk (n.d.) quote.
Best (2011) assumes that "the edible contents of a 60-gram egg weighs 55 grams" or 0.055 kg. Multiplied by 288 eggs in a lifetime gives 16 kg per hen lifetime.
