The basic method of pig feed recognition: smell, touch, look and taste.

　　闻：特定的饲料原料都有其有的芳香气味，如有异味、怪味、霉变味或无味(掺假可掩盖芳香味)就说明饲料为假劣原料。

　　Smell: certain feedstuff materials have their own fragrant smell. If they have peculiar smell, peculiar smell, moldy taste or tasteless (adulteration can cover up fragrant smell), it means that feedstuffs are fake and inferior materials.

　　摸：因为人体带有生物电，可用手反复插入饲料原料中，再抽出抖落，如果细小物质不易抖落，就说明有假。

　　Touch: because the human body is equipped with bioelectricity, it can be repeatedly inserted into the feed material by hand, and then extracted to shake off. If the small matter is not easy to shake off, it means there is a fake.

　　看：①色泽是否一致。特定的饲料原料具有其固有的光泽，如果同一批原料中有颜色不同和光泽度不一样的物质就说明有假;②粒度是否整齐。看较细小粒度的原料中是否有较整齐的细小颗粒或是否有超细物质存在，而且有一定的数量。如果有可将其破坏和特定的原料做对比，一比便知。

　　See: ① whether the color is consistent. The specific feed material has its inherent luster. If there are substances with different colors and glossiness in the same batch of raw materials, it means there is a fake; ② whether the particle size is neat. To see if there are more orderly small particles or ultrafine materials in the raw materials with smaller particle size, and there are a certain number of them. If there is a comparison between its destruction and specific raw materials, one can know.

　　尝：特定的原料都有固定的味道，如甜、酸、涩、苦、香等，如果经常尝，就会知道不同;特别是石粉、沸石、砂石等一尝便知。

　　Taste: specific raw materials have a fixed taste, such as sweet, sour, astringent, bitter, fragrant, etc. if you often taste them, you will know that they are different; especially when you taste stone powder, zeolite, sandstone, etc.

　　部分常见饲料原料掺假的识别方法

　　Identification method of adulteration of some common feed materials

　　豆粕 经销商常用大片麸片、稻壳、米糠等和磨细的黄土玉米(2316,-9.00,-0.39%)面混合制成细小颗粒，然后着上色做成“豆粕料”，也有单用磨细的黄土制粒着色的，掺在豆粕内，致使豆粕粗蛋白含量降30%以下。

　　Soybean meal dealers often mix large pieces of bran, rice husk, rice bran and ground loess corn (2316, - 9.00, - 0.39%) flour to make small particles, and then color them to make "soybean meal material". There are also those that only use ground loess to make grains and color them, which are mixed in soybean meal, resulting in the crude egg white content of soybean meal falling below 30%.

　　识别：

　　distinguish:

　　①闻，掺有“豆粕料”的豆粕由浓香变为淡淡的香或根本无香味。

　　① Smell, the soybean meal mixed with "soybean meal material" changes from strong fragrance to light fragrance or no fragrance at all.

　　②看，豆粕颜色淡黄，加热温度高的深黄，不掺假的光泽非常明显，整齐划一，而掺有“豆粕料”的豆粕整体光泽度降低，特别是“豆粕料”基本没有光泽度;把粒度整齐，偏大的取走后，剩下细小的，然后用右手食指和拇指捏起，使劲一搓，一看便知，豆粕，即使是再细小的颗粒，用两个手指是搓不细的。

　　② It can be seen that the color of soybean meal is light yellow, the deep yellow with high heating temperature, and the luster without adulteration is very obvious and uniform, while the overall glossiness of soybean meal mixed with "soybean meal material" is reduced, especially the "soybean meal material" basically has no glossiness; After taking away the larger ones, the smaller ones will be left. Then, pinch them with the index finger and thumb of the right hand, and rub them hard. It will be known that the soybean meal, even the smallest ones, can not be rubbed with two fingers.

　　③尝，真豆粕有豆香味，而掺假的无味(玉米面、石粉等)或有泥土味(掺黄土、泥沙等)。

　　(3) taste, real soybean meal has bean flavor, and adulterated insipid (corn flour, stone powder, etc.) or earthy flavor (mixed with loess, silt, etc.).

　　④水浸，取适量样品放入大玻璃杯中，用水浸泡2小时，然后用一小棒轻轻搅动，若有分层现象的，上层为豆粕、中层为玉米面(饼)、下层为黄土、钙粉、石粉等。

　　④ Soak in water, put a proper amount of sample into a large glass, soak in water for 2 hours, and then stir gently with a small stick. If there is stratification, the upper layer is soybean meal, the middle layer is corn flour (cake), the lower layer is loess, calcium powder, stone powder, etc.

　　⑤滴碘洒，取少量样品放于载玻片中，在样品上滴几滴碘洒，1分钟后若有物质变为蓝黑色，就证明掺有玉米、麸皮、稻皮等。

　　⑤ Drip iodine, take a small amount of sample and put it in the slide, drip a few drops of iodine on the sample, if any substance turns blue black after 1 minute, it is proved that there is corn, bran, rice skin, etc.