Different feeds have different shelf life. For example, compound feed is generally 1-2 months, concentrated feed is 3-6 months, premixed feed is 6 months to 2 years, and the shelf life of different seasons and products is different. It is safe to use feed within the shelf life. The enterprise is responsible for the quality of the products that meet the relevant storage conditions. If the feed is used beyond the shelf life, there will be different degrees of safety risks. If the shelf life is exceeded, especially when the storage conditions are not good, the feed will become moldy, causing livestock poisoning and even death; at the same time, mold growth will consume nutrients and energy in the feed, reduce and damage vitamins, protein and amino acids, and a very small amount of mold can also damage the feed flavor, produce putrefaction odor, and cause adverse consequences to animal health.

Pig premix

过期饲料的主要危害有：

The main hazards of expired feed are as follows:

(1)有害微生物及霉菌毒素超标，对动物健康产生影响

(1) Harmful microorganisms and mycotoxins exceed the standard, which has an impact on animal health

过期饲料更容易发生的问题是霉变，引起饲料霉变的霉菌主要有黄曲霉菌、赭曲霉菌、禾谷镰刀菌、推展青霉菌等。霉菌在生长繁殖过程中能产生大量毒素，主要有黄曲霉素素、赭曲霉素素、福马毒素和呕吐毒素等。动物采食后会降低生产性能，对动物产生多方面的危害，严重的甚死亡。如黄曲霉素是剧毒物质，对动物肝脏有强烈破坏作用。霉变饲料中毒的症状因饲料的霉变程度、动物采食的多少和采食时间的长短而不同，轻者出现胃肠炎、拉稀，怀孕母畜流产，重者出现神经症状甚死亡。

Mildew is the most common problem in expired feed. The molds causing feed mildew mainly include Aspergillus flavus, Aspergillus ochraceus, Fusarium graminearum and Penicillium pullulans. Mold can produce a lot of toxins in the process of growth and reproduction, including aflatoxin, ochratoxin, fumarxin and vomit toxin. After feeding, the production performance of animals will be reduced, which will cause harm to animals in many aspects, even death. For example, aflatoxin is a highly toxic substance, which has a strong destructive effect on animal liver. The symptoms of mildewed feed poisoning vary with the degree of mildewed feed, the amount of food taken by animals and the length of feeding time. In mild cases, gastroenteritis, diarrhea, miscarriage of pregnant female animals, and severe neurological symptoms or even death.

(2)过期饲料会造成饲料营养价值损失、风味劣变

(2) Expired feed will cause the loss of nutritional value and flavor deterioration

过期及发生霉变的饲料，不仅会造成霉菌产生大量代谢毒素，霉菌在繁殖过程中还会消耗、分解饲料中的营养物质，使饲料质量下降。在高温、高湿的外部环境下还可以激发脂肪酶、淀粉酶、蛋白酶等水解酶的活性，在霉菌、饲料酶等因素协同作用下，加快饲料中营养成分的分解速度，营养价值严重降低。如有的霉菌可使被感染的谷物中B族维生素，维生素E或某种氨基酸的含量显著下降，长期饲喂这种饲料可引起某些营养缺乏症。江西猪食过期的霉变饲料还可以使感官性质恶化，如具有刺激气味、酸臭味道、颜色异常、黏稠污秽感等，严重影响适口性。

The expired and moldy feed will not only cause the mold to produce a large number of metabolic toxins, but also consume and decompose the nutrients in the feed during the reproduction process, resulting in the decline of feed quality. Under the external environment of high temperature and high humidity, it can also stimulate the activities of lipase, amylase, protease and other hydrolases. Under the synergistic effect of mold and feed enzyme, the decomposition speed of nutrients in feed is accelerated, and the nutritional value is seriously reduced. For example, some molds can significantly reduce the content of B vitamins, vitamin E or some amino acids in infected grains. Long term feeding of this kind of feed may cause some nutritional deficiency. The stale moldy feed of Jiangxi pig food can also worsen the sensory properties, such as pungent smell, sour smell, abnormal color, sticky and dirty feeling, which seriously affects the palatability.

此外，如果饲料中含有油脂的话，过期饲料由于季节、温度等原因，易造成饲料中脂肪和油脂出现酸败等情况。饲喂这些饲料将造成畜禽应激，并且酸败或过期饲料中含有一些有机酸、游离酸等小分子物质将刺激畜禽神经系统造成畜禽兴奋，从而产生跳圈或不睡觉的恶习。

In addition, if there is fat in the feed, the expired feed will easily lead to rancidity of fat and oil in the feed due to season, temperature and other reasons. Feeding these feeds will cause stress to livestock and poultry, and the rancid or expired feed contains some small molecular substances such as organic acids and free acids, which will stimulate the nervous system of livestock and poultry, causing excitement of livestock and poultry, resulting in the bad habit of jumping around or not sleeping.

过期饲料具有许多危害，因此养殖者务必高度重视，绝不能擅作主张使用过期饲料。在养殖过程中，要根据养殖动物的数量和采食量合理购买饲料并妥善保存，避免在贮存过程中发生霉变现象，也要避免饲料的过期浪费。

The expired feed has many hazards, therefore, the breeders must attach great importance to it, and never advocate the use of expired feed. In the process of breeding, feed should be reasonably purchased and properly preserved according to the number and feed intake of breeding animals, so as to avoid mildew and waste of feed during storage.