Primary Crop Disorders: - Crop infections (gram negative bacteria, yeast, fungi) - Over-stretched crop (feeding greater than 12-15% body weight) - Aerophagia (air in the crop prevents normal crop motility) - Foreign body (bedding ...) - Crop burn - Pharyngeal or esophageal trauma (damage due to feeding tube,    crop tube, syringe) Generalized GI Statis: - Generalized disease (bacteria, yeast, viruses, parasitic infection) - Polyoma virus - Hypothermia (baby becomes too chilled) or hyperthermia (baby    becomes too hot) - Formula too cold or too hot - Improperly mixed formula (too little water, additions to the formula) - Yolk salk infection (improper absorption and subsequent infection) - Damp or wet nest box/excessively humid/dry environment. - Stress - Congenital abnormalities