Fish meal is a kind of high quality animal protein raw material. Because of its balanced amino acid content, it plays an extremely important role in promoting animal growth and development, and is widely used in feed formulation. As the world's fishery resources show a decreasing trend year by year, the world's fish meal production in recent years also has a considerable decline, prices have also increased substantially. According to statistics, the annual weighted average transaction price of Peruvian direct fire red fish meal at Chinese ports in 2010 was about 11,000 yuan / ton, and the price increased by 100% compared with 2005. The high price of fish meal has brought severe challenges to feed enterprises which need more rigid fish meal to control the cost of products. How to choose fish meal with the best cost performance is an urgent problem for feed enterprises.
First, attach great importance to the safety of fish meal products.
1. microbial contamination
Fish meal is easily contaminated by Salmonella and Escherichia coli. Feed processed by fish meal contaminated by the above pathogenic bacteria will cause serious harm to the cultured objects. Therefore, in the production, transportation and storage of fish meal to avoid microbial contamination and pathogenic bacteria detection and control, plays an important role in the safety of feed products.
2. the hazards of histamine and gastrin.
Histamine (Histamine) is a kind of biogenic amines, which is very toxic to animals. When animal protein raw materials are contaminated by bacteria containing histamine decarboxylase, such as Proteus morgani or colorless histamine bacteria, bacteria will multiply under appropriate environmental conditions to produce strong decomposition and decarboxylation of animal protein histidine, thus producing histamine. The higher the histamine content, the more serious the protein spoilage. Its molecular formula is C 5 H 9 N 3. When the body intake of histamine more than 100 mg (or 1.5 mg per kg of body weight), can cause allergic food poisoning.
The derivative of histamine, known as Gizzarosin, is formed by the reaction of free histamine and its metabolite histamine in fish meal with protein (lysine epsilon-amino) in fish meal during the production of fish meal, which is heated or dried over 130 degrees centigrade under direct fire. Myogastric erosin has much stronger toxicity than histamine. Its pathogenicity is 100 times higher than histamine. It can promote gastric acid secretion, thus promoting gastric keratinous membrane ulcer and bleeding. It has been reported that 2.2ppm's muscle gastric erosive substance can stimulate the secretion of gastric acid in poultry, causing stomach diseases, resulting in * diarrhea, liver damage and so on.
The content of histamine or myogastricin in fish meal is related to the freshness of raw fish, fish species and processing technology. For example, the muscle of red fish contains 100-1000mg/kg of free histamine, which can be quickly converted into histamine by microbial propagation. The fish meal made from fish that is not fresh or spoilage is very high in histamine content. The dried and dried fish meal is too high because of the processing temperature, which can lead to an increase in the content of erosive substance in the muscle and stomach. Eels and soft shelled turtle feed usually do not use direct fire dried fish meal.
If fish meal contains high concentration of histamine or myogastric erosin, it will pose a serious threat to the safety of feed products. Therefore, in the production of high quality feed, wet degreasing steam fish meal with histamine monitoring index should be selected to effectively ensure the safety of feed products.