1, judge by hand feeling

The detector can put his hand into a bag of grain, if the grain is dry, in the inner layer of the bag and the outer layer won't feel any temperature difference; If the moisture content of the grain is high, then in the winter, you will feel that the grain at the center of the bag is hotter than the outer layer of the grain, in the summer, you will feel that the grain at the center of the bag is cooler than the outer layer of the grain.

Take a spoonful of rice bran in the palm of your hand, squeeze and rub it with your fingers, if you feel it is too rough, it may indicate that the rice bran is mixed with rice hulls; grab a small handful of rice bran in your hand and hold it tightly into a fist and then slowly release your fingers, good quality rice bran will leave finger indentations, and mixed rice bran will be scattered and unable to form. Poultry powdered feed shows such finger indentation, indicating that its moisture content is high, because the normal moisture content of the feed is easy to fall apart. When fish meal has a high moisture content, it will be hotter to the touch, softer and wetter.

2, with the sense of taste

Through the sense of taste, you can judge the freshness of the feed and its raw materials. Fresh feed and its raw materials taste better, and after a certain period of storage, the oils and fats due to the presence of free fatty acids will be rancid, resulting in a very poor taste. Expired feed has an unbearable stale, moldy smell.

By biting and tasting the cake meal, you can distinguish the freshness of the cake meal, the degree of rancidity, the degree of mold and the degree of adulteration. At present, the vast majority of cake meal mixed with rice bran, castor seed, cottonseed and other cheap oil seeds. The vast majority of adulterants can be distinguished by the use of feed microscopy, chewing, tasting, and identifying color and odor. It is easy to determine the moisture content of grain or cake meal by biting and chewing it with your teeth; dry feedstuffs should be crunchy, hard and friable to the bite. If fish meal, broken rice and other raw materials mixed with sand, gravel, chewing will feel gritty.

3. Observe with your eyes

Check the natural color of the raw materials, adulterant content, mold growth, caking, insect bites and any other abnormalities, the use of these moldy caking feed and feed produced with spoiled raw materials will lead to low input-output ratio and high mortality. Moldy grains can turn green, gray or black. Expired or improper storage and high moisture content of the ingredients lead to caking and mold growth. The adulteration of oil-extracted nut cake meal with rice bran or other cheap fruits, and the adulteration of fish meal with powder from shrimp heads, crab shells, shells, etc., can be detected by careful observation and microscopy of the feed. Because of the less oil content is easy to ensure the quality of light-colored fishmeal is better than dark-colored fishmeal.

With the feed microscope than directly with the eyes to check more accurately, in a wider range of application of the microscope, feed ingredients in the adulteration of foreign matter such as peels, shells, stones and cheap substitutes, can be easily checked out. Feed microscope can be used to discern the feed ingredients in the adulteration, such as sand and gravel, peel, husk, spoiled grain, fishmeal, meat meal mixed in the hair meal, skin meal, sesame seed meal, sunflower seed meal mixed in the castor seed meal, cottonseed meal, and other similar cheap substitutes.

Simple chemicals and reagents can differentiate feed ingredients. For example, the concentration of 2.5% ammonium molybdate solution added to the feed ingredients, shaking no precipitation, indicating that it may be mixed with calcium carbonate or sodium carbonate; if there is no shaking on the production of a yellow precipitate, indicating that it may be mixed with phosphate or bone meal, calcium dihydrogen phosphate; if the concentration of 1% silver nitrate solution added to the feed ingredients, producing a white precipitate, indicating that it is mixed with chlorides; if no Precipitation, indicating that there is no chloride; will be added to the feed ingredients of distilled water, the solution becomes white, indicating that it is mixed with dairy products.

4, with the nose smell

For rice bran, fish oil, oilseed, meat meal, silkworm pupa powder, fat, oil and other oil-rich feed ingredients, due to expiration or incorrect storage will produce rancidity, through the sense of smell can be distinguished. The use of these rancid ingredients in animal feed destroys the fat-soluble vitamins in the feed, and the feed has an extremely poor taste, reducing its palatability and conversion rate. If the feed and its ingredients have a musty smell, it means that there is mold growth in it, and such feed should never be fed to animals. Meat powder mixed with leather waste, hair powder or silkworm pupa powder will have a strong leather flavor or animal fatty acid failure of the odor, this kind of meat powder mixed with adulterants is not easy to digest.