First, fish meal is commonly used in animal feed and is often mixed with cottonseed cake, rapeseed cake, urea, and sediment.
1. Visual inspection: High-quality fish meal should have a uniform texture, with visible fish muscle fibers, small amounts of scales, bones, and eyes. It should appear yellow, yellow-green, or brownish-yellow, and feel loose when held in the hand. It should not be sticky or clump together, and should have a distinct fishy smell without any odd odors. Adulterated fish meal may look inconsistent, lack visible fish parts, and may feel too fine or powdery. It might also clump easily and have a weaker fish smell or an unusual odor.
2. Smell test: Take 20 grams of fish meal and 10 grams of soybean meal, place them in a bottle, add some water, cover it, and heat for about 15 to 20 minutes. If you detect an ammonia-like smell after opening, it suggests that urea has been added.
Second, bran is another common feed ingredient, often mixed with talcum powder or rice bran.
If you insert your hand into a pile of bran and pull it out, and there's white residue that doesn't easily fall off, it likely contains talcum powder. If the bran feels slightly bulgy when held, it may be mixed with rice bran. Pure bran should feel smooth and not clump together.
Third, soybean meal is frequently adulterated with sediment, crushed corn, or stone powder.
1. Water immersion method: Take 25 grams of sample and soak it in 250 ml of water for 2-3 hours. After stirring gently, if sediment is present, it will settle at the bottom while the soybean meal remains on top. 2. Iodine test: Place a small amount of the sample on a white dish and add a few drops of iodine. If it turns blue-black within a minute, it indicates the presence of corn or rice husk.
Fourth, methionine is an essential amino acid often found in feed. Fake versions may contain starch, glucose, or stone powder.
1. Sensory test: Genuine methionine is white or slightly yellow, with a sweet taste. Counterfeit products are usually grayish, lack crystal luster, and have an unpleasant smell. 2. Burning test: Burn 1 gram of the sample in a porcelain dish at 550°C for one hour. Real methionine leaves very little ash. 3. Solubility test: Dissolve 1 gram of methionine in 50 ml of distilled water. If it dissolves completely, it is genuine; if not, it may be fake.
Fifth, shell powder is often used as a calcium source. Authentic shell powder should contain over 70% small shells, with more than 30% being large shells. After grinding, these should provide at least 36% calcium content.
Sixth, bone powder is commonly mixed with stone powder, shell powder, or fine sand.
1. Visual inspection: Pure bone powder appears as gray-white particles with some honeycomb-like structures. Adulterated versions may have fewer or no honeycombs, and the color may be whiter than natural bone powder. 2. Hydrochloric acid test: When placed in dilute hydrochloric acid, real bone powder emits a "gritty" sound, does not bubble, and eventually dissolves, making the solution cloudy. 3. Incineration test: Burn a small sample. Real bone powder produces steam and a burnt hair smell, while fake samples produce less steam and odor.
Main ventilation fan non-stop wind reversing system
Coal Mine Ventilator Blower,Coal Mine Ventilation Fans,Coal Mine Ventilation Blower,Non-stop Wind Reverse Damper
Yuncheng Anhong Enery-saving Explosion-proof Fan Co.,Ltd. , https://www.anhongfengji.com