Table 1.
External and internal stress factors in poultry production farms¹

Stress factors	Specific stressors
Technological stresses	Chick placement
	Increased stock density
	Weighing, grading, group formation, catching, transferring to breeder houses
	Prolonged egg storages conditions, incorrect incubation regimes
Environmental stresses	Inadequate temperature, ventilation, and lighting, increased dust
Nutritional stresses	Mycotoxins, oxidized fat, toxic metals, imbalance of minerals and other nutrients, lower water quality, usage of coccidiostats and other drugs via feed and water
Internal stresses	Vaccinations, microbial or virus challenges, gut disbacteriosis, pipping and hatching

Adapted from Surai and Fisinin (2016).