Feeding value and identification of corn gluten meal

Corn gluten meal is a by-product of corn grain produced by the pharmaceutical industry to produce starch or wine industry. It has rich protein nutrition, special taste and color, and can be used as feed [1], and fish meal commonly used in feed industry . Compared with bean cake, the resource advantage is obvious, the feed value is high, it does not contain toxic and harmful substances, and it can be directly used as protein raw material without reprocessing. The advantage of corn protein powder as a feed development is that the industrial scale production is expanding, the product has less anti-nutritional factor content, potential development, and good feed safety. Therefore, corn protein powder has a broad production prospect.

　　1 Composition of corn gluten meal

　　Corn gluten meal, also known as corn gluten meal, consists mainly of corn protein and contains small amounts of starch and fiber. Protein is present in both the soluble protein and the insoluble protein in the gastrointestinal tract of pigs. Insoluble proteins are easily combined with other macromolecular organic or trace elements , and are not easily absorbed and utilized by animals. Almost all of them are excreted by animals and constitute feces. The composition of dry matter. Starch contains resistant starch and chronic starch. The resistant starch is not easily hydrolyzed by amylase in the digestive tract. After absorption of water, the viscosity increases, affecting the peristalsis of the chyme and affecting the digestion and absorption of nutrients. The fiber component of corn gluten meal consists of NSP and lignin. The content, type and structure of NSP affect the digestion and absorption of the diet to a certain extent , and also affect the utilization and excretion of nitrogen [2].

　　2 Nutritional components of corn gluten meal

　　The different nutrients of corn protein powder produced by different uses and different production processes directly affect the effective utilization rate and the economic benefits of the feed formulation . Zhang Fengbin [3] reported that the corn protein powder produced by the pharmaceutical industry contains more than 60% protein, and its nutritional composition is shown in Table 1. It can be seen from Table 1 that the protein content is 21% and 3.7% higher than that of bean cake and fishmeal, respectively. It is a feed material with high protein, while the crude fiber content is 3.9% lower than that of bean cake; fat in medical corn protein powder The content is higher than that of bean cake and corn seed. After being formulated into feed, the fat content of the diet is high, which is beneficial to reduce the oxidation of amino acids to produce more body protein, and also inhibit the conversion of glucose and other precursor substances into fat; under high temperature conditions, Also beneficial for energy intake,

　　Reduce the body heat consumption of livestock and poultry and slow down heat stress.

　　Table 1 Comparison of nutrient contents of corn protein powder, bean cake and fish meal

Alcohol zein powder is a by-product of the wine industry. Its protein content is low, its crude fiber content is high, and its nutritional value is not as high as that of medical corn gluten. However, due to the presence of unknown growth factors, it can significantly improve animal performance after being added to the diet. .

3 Application of corn gluten meal in livestock and poultry feed

3.1 Corn gluten meal is used as feed protein source

Corn protein powder has high protein content and rich amino acids. It can be used to replace protein feed such as bean cake and fish meal in the feed market where soybean cake and fish meal are short. The laying hens with corn gluten meal can increase the egg production rate by about 15%. It can prevent and cure chicken cartilage and other diseases, and promote health and promote growth, which is conducive to improving egg protein quality.

The protein content of corn gluten meal is directly related to the apparent digestible energy value of pigs. The energy-protein ratio is suitable or the raw materials with balanced essential amino acids and non-essential amino acids have higher energy digestibility. Guo Liang (2000) added corn protein powder with different protein content in the basic feed of pigs (CP: 52% from northeast, 47.4%, 32% from Beijing), and the added weights were 20%, 25%, 30%, respectively. The digestive energy of pigs, the test results show that (Table 2), the apparent digestibility of corn protein powder containing 32% crude protein is higher, the reason may be that its energy and protein ratio is more appropriate.

In the cattle industry, the use of corn protein powder as a concentrate allows some of the proteins that cannot be digested by the rumen to be better digested and absorbed in the small intestine. Corn gluten meal contains linoleic acid, which promotes lipid metabolism in chickens and promotes the polymerization of essential amino acids.

Table 2 raw material analysis indicators and their energy values

3.2 Corn gluten meal improves broiler coloration

Although the coloration of broiler epidermis has nothing to do with its nutritional value, due to the influence of traditional culture, consumers and breeders still use broiler commodity coloring as one of the main indicators to measure the quality of broiler chickens, directly affecting the price of broiler market. And demand.

Broilers cannot synthesize lutein by themselves. They can only be obtained from feed. At present, in order to obtain the ideal skin color, chemical synthetic colorants such as garcin red and garcin yellow are added to the broiler feed. The price is higher, the feed cost is increased after addition, and remains in the livestock and poultry. The content of lutein in corn gluten meal is as high as 90-180 mg/kg, which is more than 5 times that of yellow corn. It can be effectively absorbed, and the egg can be golden yellow, which can make the skin of the chicken yellow ^[3] . The price of corn gluten meal is close to the price of bean cake. In view of this, corn protein powder plus arsenic acid can be used instead of chemically synthesized colorants to improve the coloration of broilers.

Fu Weilin ^[4] reported that 2.5% corn gluten meal and 90 mg/kg arsenic acid were added to the test group diet, and 100 mg/kg garcin red was added to the colorant control diet. No coloring matter was added to the diet. As a result, the color of the test group and the colorant control group was significantly higher than that of the blank control group. The difference between the color of the test group and the colorant control group was not significant. The broiler of the test group was not significant. The color is dark yellow and the appearance is in line with people’s consumption habits. From the effect of slaughtering broiler color, the effect of adding corn gluten meal and the effect of adding garcin red is close to it, which is significantly higher than that of the control group; the coloring effect of natural lutein in feed is better than that of chemical synthetic colorant. The effect is slightly worse, but by adding aspartic acid, it promotes the metabolism of the body and increases the deposition rate of lutein in the feed, thereby changing the coloration of the broiler epidermis, and the effect is obvious.

4 Identification of adulteration of corn gluten meal and determination of its incorporation

With the rapid development of animal husbandry , adulteration of the feed market has occurred, especially high-protein feeds such as corn gluten meal, in which corn flour is blended with yellow pigment to change the appearance of the product, and urea is used to increase the protein content. Achieve the purpose of falsehood. The adulteration of corn gluten meal not only reduces the intrinsic quality of the product, but also causes significant damage to livestock and poultry. In order to quickly detect the quality of corn gluten meal, Lu Lijun ^[5]used a protein analyzer to use a non-digested, direct distillation method to make a linear regression based on the correlation between the nitrogen in the zein powder and the consumption volume of the titrant in the amide form. Handle and quickly make qualitative identification. This method is completed by distillation, absorption and titration. It takes only 8 minutes to measure a sample, which meets the requirements of rapid measurement. The return equation is Y=-3.05+5.87X, and the confidence interval of the regression line is Y=-3.05+5.87X soil 0.82.

5 Conclusion

The corn protein powder has high protein content and rich lutein content, and has high feeding value. It has a wide range of sources and will be widely used in the feed industry in the future, especially its coloring effect. The application prospect in poultry feed will be Very broad