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.
The main hazards of expired feed are as follows:
(1) Harmful microorganisms and mycotoxins exceed the standard, which has an impact on animal health
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) Expired feed will cause the loss of nutritional value and flavor deterioration
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.
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.
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.