Identification measures of feed quality

The main results are as follows: (1) Comprehensive use of sensory method to identify feed quality 1.1 the main way to identify feed quality with eyesight is to observe the variety, shape and color of feed. During the inspection, you can hold a handful of samples on the palm of your hand or on white paper, flatten them gently with your hands, focus your attention on a certain part of the sample, identify carefully, and check the uniformity, shape, color and luster of the particles. For grain raw materials with skins, we can also observe the thickness of the skins, the worm-eaten situation, the fullness and the number of incomplete grains, and so on. For some varieties, the water content can even be estimated, such as corn, the color and shape of the embryo can be observed, if the color is bright, the embryo is shrunk without hair, the grain is neat and broken, and its moisture is generally less than 15%. If the color is dark, the embryo is not shrunken and haired, then its moisture may be more than 16%. Can also judge from the color of the feed and whether it has been attacked by mold, such as good quality of its fresh color, good luster; after high temperature or storage for a long time, the feed color darkened, lost luster, some accompanied by caking phenomenon, scab corn pink red; Penicillium, Aspergillus reproduction can make rice yellow. 1.2 judge the quality of the feed by hand touch, that is, put the sample into the palm of the hand, touch it with the finger, identify the smoothness and roughness of the grain with the touch of the hand, and then twist and press it with the finger to identify its soft, hard, full, shrivelled or according to the temperature of the neutron particle in the palm, specific gravity to identify moisture. For example, corn can also be nailed into the embryo, if it feels relaxed and soft, the moisture is larger, otherwise, the moisture is less than 14%. In the identification, the hand can also be inserted into the feed, such as easy to enter, smooth sound, then the water content is low, such as stagnation is not easy to insert, then the water content is high. For powdered feed, you can also hold the sample by hand, such as puffy, rough, easy to scatter when released, then the moisture is lower. Attention should be paid when touching feed with hands, fingers should be clean, hands should not sweat, and tactile methods should be chosen according to the grain shape and characteristics of feed. 1.3 distinguish feed quality by smell because all kinds of feed or finished products have a certain smell, when the feed loses its normal quality, it will produce a variety of peculiar smell. The smell of ① mildew and rot. This smell is due to the high moisture content and exuberant respiration of the feed, which causes the temperature to rise, so that the feed becomes hot and begins to mildew. It is easy to occur when the feed is not properly managed in summer Meiyu weather. ② fermentation odor. When the feed is hot, because part of the starch turns into alcohol, it will produce a smell similar to that of flour fermentation. ③ insect odor and other odors. The feed is harmed by some warehouse insects, because the secretion of the warehouse insects can cause the stink of insects. During transportation or storage, feed may also absorb the smell of gasoline, kerosene or other substances in the air, thus reducing feed quality. 1.4 through the taste test, the feed quality is good or bad. In general, the feed raw materials and finished products with normal quality have a certain fresh flavor. Inferior ones may have a peculiar smell, such as slightly feverish and moldy ones with sweet taste, slightly heavier ones with alcoholic taste, and heavy ones with sour taste; bitter taste indicates complete deterioration. If a small amount of sediment is mixed in, the teeth will be scratched through the mouth. For the above sensory identification methods, the quality of feed should not be judged only on a certain point, but should be comprehensively analyzed from the results of the inspection. (2) to identify the feed quality by water-dissolving method, put a small amount of samples in a clean cup, rinse with water, observe whether there are sand grains at the bottom of the cup, whether the water of the washed sample becomes muddy and discolored, and whether the properties of the washed sample are separated. It is possible to identify inferior feed that is dyed in order to look similar to high-quality feed. 3To identify feed quality by burning method and indicator method, suspicious particles or a few samples in the sample were cauterized in a crucible, and the changes after burning and the smell of the combustion process were observed and judged. It can be used to identify plant components and mineral components in animal protein. PH test paper and iodine wine can also be used to judge the acidity and basicity of the sample and whether it contains starch or not according to the color change of the sample after adding indicator, which is mainly used to identify the alkaline impurities in the protein feed, the alkaline impurities in the mineral feed and the non-amino components in the amino acid feed. 4 Identification of the quality of feed raw materials commonly used for large-scale farming in rural areas 4.1 the normal sensory characteristic of corn is that the grain is uniform, yellow or yellow-white. The key to testing corn is the moisture content. The preparation of feed requires that the moisture content of corn should not exceed 14%, otherwise the feed quality will be greatly reduced. The specific methods for testing the moisture content are as follows: ① puts corn on the palm and feels its soft and hard by twisting and squeezing. If the grain is hard, the moisture is less, on the contrary, the moisture is large; ② tooth crushing identification shows that when the moisture content is about 14%, the embryo water shrinks obviously. When the teeth are clenched and make a crisp sound, the corn with more than 16% moisture does not shake the teeth when the teeth are bitten, but there is still a sound when the teeth are crushed. The higher the moisture content, the less the sound, or even none at all. 4.2 Wheat bran is made from all kinds of wheat. One of the feed raw materials in the by-products obtained from the conventional process can be selected by smelling its taste first, and must not use sour, moldy or fermented wheat bran, and then look at its properties, requiring fine crumbs and fresh color. And touch with the hand without feeling its moisture content (should be less than 12.5%). 4.3 Soybean meal is a kind of feed raw material after extracting oil from soybean by pre-pressure extraction. The soybean meal of good quality is in the shape of light yellow or yellowish irregular fragments, the color is the same, and there is no fermentation, mildew, caking, moth and peculiar smell. But the newly produced soybean meal smells fishy. In addition, the moisture content of soybean meal should not exceed 14.5%, and the hand grasp is very good. If the moisture is too high, the hand grasp stagnates. This kind of soybean meal is not suitable for use. If the soybean meal has been purchased, it should be used after the moisture content is reduced, such as drying. In order to avoid causing feed mildew and other conditions. When choosing and buying soybean meal, we should also pay attention to not using soybean meal with many impurities, as the protein content of such soybean meal is low, which will affect the feed quality. For soybean meal mixed with sediment, 5% Mel 10% stone powder or chopped corn, the identification methods that can be used are: ① water immersion method. Soak 25g soybean cake (meal) in a glass filled with 250mL water for 2-3 hours, then stir it gently with a wooden stick. If adulterated, it can be seen that the upper layer is soybean cake (meal) and the lower layer is sand. ② iodine identification method. Take a little soybean cake (meal) on a clean white porcelain plate, spread it thin, lay it flat, drop a few drops of iodine on it, after 1min, if some of the substances become blue-black, it may be mixed with corn, wheat bran, rice husk and other substances. 4.4 Fish meal fishmeal is made from fish, shrimp, crab and other aquatic products, such as fish head, tail, viscera, etc. as raw materials, dried, defatted, crushed or steamed, pressed and crushed. The protein content of fishmeal is more than 50%, and the price of fishmeal is expensive. The addition amount of fishmeal in formula feed is generally the same as that of major mineral additives, and its quality directly affects the feed quality. ① visually discriminates the color and processing method of fishmeal. After degreasing, the color of artificially dried fishmeal is dark and brown, while that of naturally dried fishmeal is lighter, yellow or bluish white. High-quality fishmeal can see slender muscle bundles, fish bones, fish orders, fish pieces, etc., no parasites and mildew. ② smell, good fish meal has fishy smell, with the degree of corruption corresponding to the fishy smell and irritating smell, some inferior products have abnormal odor or anxious smell, ③ touch, high-quality fish meal twisted by the fingers, the texture is soft and orange-shaped meat. Inferior fish meal or adulterated fish meal has a rough texture, and its hardness, viscosity and foreign matter can be observed after finger twisting. The authenticity, pros and cons of fish meal can be judged by the above three sensory identification, such as mixed with blood powder, sand, leather, salt powder and so on. The quality of 4.5 amino acids directly affects the quality of feed. The two most commonly used amino acids are lysine and methionine. ① lysine: small white or brown particles or powder, tasteless or slightly sour, sour in the mouth, uniform texture, burns out quickly when the lysine content is higher than 98.5% in human fire, and gives off an unpleasant special smell, like a charred feather. On the other hand, adulterated lysine has abnormal color, incorrect smell, stinging or fragrant smell, rough handle, astringent feeling, obvious residue in combustion and no charred feather smell after burning. ② methionine: White or yellowish crystalline powder or flake, reflective, the real product has a special smell, slightly sweet in the mouth, no astringency, smooth and greasy hand texture Burning methionine in the fire burns out quickly when the methionine content is more than 98.5%, and emits a special bad smell after burning, while adulterated methionine is yellow or gray, has little crystallization, has a bad smell, has no sweet taste in the mouth, has a strange smell, has an impurity-like astringent feeling, feels rough, burns out incompletely when it is put into the fire, and has residue, and there is no special charred feather smell after combustion. -- very simple and practical-- Thank you, landlord.