The use of new corn in feed

With the launch of the new corn, the proportion of application in feed gradually increased, but the new corn is affected by moisture content, maturity, mildew degree, plumpness, drying method, storage conditions and varieties, and its quality is different from that of the old corn. A series of problems will occur after the preparation of livestock and poultry feed, such as livestock and poultry runny, low feed returns, etc. Breeding enterprises and feed production enterprises must pay attention to the problems in the use of new corn as raw materials, take corresponding measures, then the specific problems will exist in the use of new corn in the process?

1. Water problem.

After drying, the water content of the new corn is relatively large, most of which is above 17%, while the dry corn is less than 13%. The new corn, which is 17% water, has diluted nutrients and reduced nutrient content after processing into feed. High water content will destroy active ingredients such as vitamins in the diet. It also reduced the level of metabolizable energy and crude protein in the diet. The relative reduction of energy increased animal feed intake and reduced feed conversion rate.

2. Resistant starch of new maize.

Corn is a post-ripening crop, and the content of resistant starch in new corn is high. Generally, it takes about 45 days of post-ripening to gradually reduce resistant starch. Resistant starch, also known as resistant starch or indigestible starch, refers to the starch and starch degradation products that cannot be hydrolyzed and absorbed by α-pancreatic amylase in the small intestine of healthy animals [1]. Resistant starch in new corn is an anti-nutrient factor of indigestible substances in livestock and poultry breeding. Resistant starch stimulates intestinal peristalsis, reduces the residence time of feed in the intestine, and easily causes soft stools and even diarrhea in livestock and poultry. Resistant starch affects the absorption of other nutrients, has a physical embedding and barrier effect on normal starch and other nutrients, and cannot be contacted by amylase and other digestive enzymes, so it affects the normal digestion in livestock and poultry and reduces the performance of animals.

3. Mycotoxin problem of new corn.

Corn mycotoxin is divided into storage mycotoxin and field mycotoxin. Zearalenone, vomitoxin, T-2 toxin and aspergillus fumigatum are field mycotoxins, which have been contaminated by Fusarium fungi and other field mycotoxins during field growth and harvest. Ochratoxin and aflatoxin belong to storage mycotoxins. When new corn is stored in high temperature and humid storage conditions, aspergillus and other storage molds are easy to breed and produce these mycotoxins. Sichuan Province has been in a humid climate for a long time, and the pollution of storage mycotoxins such as aflatoxin is relatively serious. The northeast and North China regions are the main corn production areas. During the process of harvesting, drying and storage, the water content of corn is not reduced in time. As a result, a large number of different types of mycotoxins can be produced by mildew during harvesting, drying and storage [2].

A solution to the problem of new corn use

1. Due to the high water content of new corn, it is difficult to add steam when the feed is conditioned, and the amount of steam absorbed by the material is less and the gelatinization degree is not high. If the temperature is too low in late autumn and early winter, the gelatinization effect will be worse if the conditioning time is too short, which will directly affect the feeding effect. In terms of processing technology, measures such as reducing corn crushing size, increasing conditioning temperature and extending conditioning time will help gelatinize starch, improve its digestion and utilization, and reduce adverse effects [3].

2. In view of the high content of resistant starch in new corn, special compound enzyme preparation can be used to partially eliminate the problem. The protein matrix wrapped around starch granules and the starch-fat complex contained in starch all hinder the digestion of starch. Therefore, protease and lipase should be appropriately added into the enzyme preparation to improve the digestion of starch. In production, commercial saccharifying enzymes (various types of amylases) or fortified amylases, proteases and lipases can be selected as compound enzyme preparations specifically for the use of new corn [4].

3. New corn is mildew proof. Storage of new corn requires ventilation, dehumidification and disinfection to avoid insect damage and mildew of new corn due to humidity, closure and other adverse environment. When the new corn is stored, it needs to be separated by wooden boards to keep its underside dry. The detoxification methods of mildew corn and new corn contaminated by mycotoxin include physical detoxification, chemical detoxification, biodegradation detoxification and adsorption detoxification. Among them, the traditional physical and chemical detoxification has disadvantages such as unstable effect, large loss of nutrients, influence on palatability of feed, and difficulty in scale production, so they are not used in production. Biodegradation and adsorption detoxification have been widely used in production practices [5].

4. Dietary formula can be adjusted to use some substances that can improve the body's antioxidant capacity and liver detoxification, such as vitamin C, vitamin E, methionine, organic selenium, etc., whose function is to protect the liver and improve the body's detoxification ability to mycotoxin.