【正文】 Vitamin E and stress response Stress (stress) refers to the sum of nonspecific response to external or internal very stimuli, caused by stress factors known as stress factors or stressors (stressor). The mobilization of body tissues and organs to deal with, to adapt to the series of responses to stress stimuli showed that general adaptation syndrome (GAS). It is organized as follows: ① the physiological changes of adrenocorticotropic hormone (ACTH) production and increased release of, anterior pituitary enlargement. ② adrenal hyperplasia enlargement. ③ due to increased release of corticosterone and adrenal cholesterol secretion decreased. ④ poult reaction are most sensitive to tissue lymph, thymus, bursa of Fabricius and spleen atrophy。 adult chicken because of the influence of gonadal steroids, only the bursal atrophy. The white blood cell changes, showed lymphopenia, heterophils increased. Increase the blood concentration of citric acid. The growth retardation, decreased body weight. The modern intensive livestock production, automation, in order to maximize the level of livestock and poultry production, increase economic efficiency, to livestock and poultry as production machine. The production process and technical measures adopted are often contrary to the animal39。s physiological needs. The resulting stress leads to decrease of slow growth, reduced fecundity, productivity and product quality variation, the immunity of livestock and poultry, causing great harm to livestock and poultry production. In the modern industry production, vaccines for the prevention, control and eradication of infectious diseases of livestock play an extremely important role, immunization hand to protect the body against animal pathogens, on the other hand, as a kind of special stress factor resulting in immunological stress, some damage to the body, the damage is not only affect the growth and development and the production performance of livestock and poultry, and may cause a few animal death. 1,the stress response mechanism The mechanism of stress response is a plex process, according to the Canadian pathologist Hans Selye stress theory, from the stress state of view, can be divided into three periods: alert period (emergency reaction stage), resistance (resistancestage) and failure stage (exhaustion stage). The alert period. The body has not yet received the adaptation period, the body is early response to stressors. According to the physiological and biochemical changes of different, this period can be divided into shock and reverse shock phase. Shock phase as temperature and a decrease in blood pressure, blood concentration, inhibit the nervous system, muscle tension decreased, and then to tissue degradation, hypochloremia, hyperkalemia, gastrointestinal ulceration, body resistance is lower than the normal level. Shock is sustainable for a few minutes to 24 hours. The stress response to enter the shock phase, the defense has been strengthened, increased blood pressure, serum sodium and serum chloride increased, blood potassium reduced, blood glucose increased, catabolism strengthen, atrophy of thymus, spleen and lymph system, eosinophilic leukocytes and lymphocytes decreased, adrenal hypertrophy, improve the total resistance, even higher than that of normal level. In the period of resistance. The body to overe the stress source and get fit, many performance and panic reaction on the contrary, the new supersedes the old. To be normal, assimilation dominant, white blood cells and adrenal cortex hormone content tended to be normal, systemic nonspecific res