Why can not long-term high-fat diet? Rice bran, fish meal, yeast, oil cakes, full-fat soybeans and other high-fat feed and a large number of feed with fat, fat oxidative deterioration during storage results in reduced feed value. In the early stage of storage, high-fat diets begin to decrease in peroxide value, while the carbonyl value is almost unchanged, so the probability of oxidative rancidity is small; but with the prolonged storage time, especially under high temperature conditions, due to the fat inside the high-fat diet Enzymatic action, fat hydrolysis, generate large amounts of free fatty acids, so that the acidity of high-fat ketone material rises sharply, the digestibility of fat is reduced, and the pH of the feed decreases. If soybean oil is oxidized, the contents of various oxidation products increase: In the early stage of oxidation, the natural antioxidant a-tocopherol is consumed first and the content decreases; when a tocopherol is substantially consumed, peroxide begins The content increased sharply and peaked; as the oxidation progressed, the color of the oil increased. From the peak of peroxide value, the decomposition of peroxide rapidly increases, and carbonyl compounds such as aldehydes and ketones are accumulated. The resulting free fatty acids are further integrated with the peroxide as the oxidation progresses, the viscosity of the oil increases, the molecular weight increases, and the color becomes lighter, the content of a-tocopherol is reduced to a very low level. In addition to the influence of temperature on the oxidation of oils and fats, ultraviolet light and other light, trace elements, especially iron, copper, cobalt, etc. can also promote fat oxidation. Oxidized oil can cause nutritional brain encephalomasis, decrease of plasma vitamin E content, development delay, dyspepsia, intestinal hypertrophy, feed palatability, feed intake, weight loss, and feed efficiency. In order to prevent oxidation and deterioration of high-fat diets, the storage environment should be improved. It is best stored at low temperature and low humidity. Below 7o% relative humidity, feed moisture content of 13.5% or less, can better store feed, but for the sake of safety, high fat feed should not be stored for a long time.