Trough-headed meat is pig's neck meat, which belongs to garbage meat, and its scientific name is rotten head meat. The groove head meat has lymph glands. In the process of feeding pigs, people often feed leftovers or spoiled or even rotten things. Pigs are easy to be infected with bacteria or viruses, affecting pig organs and immune organs such as lymph glands. Bad head meat is inedible.
According to "Operating Rules for Pig Slaughtering in People's Republic of China (PRC)" and China's national standards, the slaughtered pigs must be trimmed, trimmed, bled and cut in sequence, and the pork can only be stamped after passing the inspection by professionals. In order to reduce the cost, some unscrupulous shops usually use groove meat as meat stuffing, mix a small amount of pork belly and pigskin, and add seasoning to make steamed buns or jiaozi. Most cooked buns are not eaten or seen by jiaozi residents.