Comrade Zhang Bin: Hello! The answer to your question is as follows: chicken, cow, sheep and pig bones can be processed into meat and bone meal. Bone meal is made from mixed bones of livestock and poultry by degumming and degreasing. It mainly contains a lot of minerals such as calcium phosphate and magnesium salt, and organic substances such as colloid and protein. The phosphorus content is more than 30%. Feeding livestock and poultry with bone meal can not only promote their growth and development, enhance their physique, but also improve their milk production and egg production. Here are some methods of making bone meal: 1, decocting method. Generally suitable for rural families to make their own. Boil the miscellaneous bone in a pot with water, or stir with 1 part of quicklime and 2 parts of plant ash with water, take clear liquid to boil the miscellaneous bone, and remove the fat and colloid removed from the miscellaneous bone while boiling until the bone does not contain oil. Then the bones are dried, crushed and ground into powder. 2. Processing of coarse bone meal. ⑴ Crushing: Crushing the bones into small pieces and boiling them in a pot for 1-8 hours, with the purpose of removing fat from the bones. When processing coarse bone meal, it is best to combine it with boiling to extract bone oil and bone acid. In this way, bone meal, bone oil and bone glue can be obtained. (2) Drying: after the water is drained and dried, it is put into a drying room or a drying furnace and dried at 100- 140℃ 10- 12 hours. ⑶ Crushing: The dried bones are ground into powder by a crusher or a stone mill to obtain the finished product. ⑷ finished product specifications: different bone raw materials have slightly different components of bone powder. Generally, the bone powder of fresh bone processing: protein 23%, calcium phosphate 48%, fat 3%, and crude fiber less than 2%. Third, the processing of steamed bone powder. It is made from the residue of bone oil extraction, that is, the bone is put into a sealed cylinder, steam is introduced, and it is heated at the temperature of 105- 1 10℃. Drain the oil once every 1 hour to remove most of the fat in the bone, and at the same time, part of protein is decomposed into glue, which can be used as raw material for making glue. Steamed bone powder is obtained by drying and pulverizing bone residue removed by boiling and steaming. The finished product is white, easy to dry and digest, and has no special smell, but the content of protein is less than that of coarse bone meal. The above contents are for reference only.