FIELD: medicine； pharmaceuticals.SUBSTANCE: present invention relates to a method for production of egg yolk with a very high content of antisecretory factor (AF) proteins and products based thereon. Egg yolk for treating and preventing diarrhea and dehydration, containing at least 0.05 ng/ml of an antisecretory factor (AF) protein fragment with an amino acid sequence disclosed in SEQ.ID.NO.1 and/or SEQ.ID.NO.2. Yolk fodder food. Method of egg yolk production. Egg yolk for treating and preventing diarrhea and dehydration, obtained by the method described above. Application of egg yolk during treatment and/or prevention of painful conditions, caused by one of selected from group consisting of extreme release of body fluids, discomfort due to physiological imbalance, inflammation, edema, arthritis, glaucoma, migraine, burns and/or traumatic injuries in and on the body. Egg yolk application in treating diarrhea and/or dehydration. Application of egg yolk during treatment and/or prevention of any one of diseases selected from a group consisting of inflammatory diseases, malignant neoplasm, glioblastoma, intraocular hypertension, compartment syndrome, Parkinson's disease, Alzheimer's disease and diabetes. Application of egg yolk during neuroprotection. Application of egg yolk with optimization of delivery and/or cellular absorption of pharmaceutical substance and/or dosage form, such as a malignant neoplasm. Application of egg yolk in immunotherapy. Egg yolk application in radiation therapy or gene delivery to a tumor cell. Egg yolk application improves nerve tissue repair. Application of egg yolk with improvement of proliferation of stem cells and precursor cells. Application of egg yolk with improvement of apoptosis of stem cells and precursor cells. Application of egg yolk with improvement of differentiation of stem cells and precursor cells. Application of egg yolk with improved migration of stem cells and precursor cells and cell derivatives. Application of egg yolk
