What do you feed your flock?
Please read this and notice these specific sentences:
https://www.merckvetmanual.com/poul...eproductive-system/egg-peritonitis-in-poultry
"Management of body weight and uniformity, reproductive development (ovary follicle growth and maturation), and drinking water sanitation are the best preventive strategies."
"Overfeeding broiler breeder hens during sexual maturation can increase numbers of large, yellow ovarian follicles. When hens have too many large ovarian follicles, a problem described as erratic oviposition and defective egg syndrome (EODES) results."
and
"
Overweight hens may also have a higher incidence of erratic ovulations and mortality associated with egg peritonitis."