Fishmeal is made from whole fish or fish scrap (fish heads, fish tails, fins, entrails, etc.) as raw materials, and after cooking, squeezing, drying and crushing. Fishmeal has a high protein content, amino acid balance, and unknown growth factors. It is a well-recognized animal protein feed and a good feed for balancing minerals, especially trace elements.
At present, as the price of fishmeal on the international market continues to rise, there are more fake and inferior fishmeal products on the market. Some of these counterfeit fishmeal are processed from spoiled fish, and some are mixed with other raw materials (meal mash, cotton aphid, Feather powder, leather powder, urea, salt, sand, etc., posing as fishmeal. Although some fishmeal are not adulterated, the quality of the fishmeal varies greatly due to the influence of raw materials, processing techniques, packaging, transportation, and storage, especially the freshness of fishmeal. Freshness directly affects the amino acid content of fishmeal, the palatability of feed and the content of toxic substances.
We generally use histamine, volatile base nitrogen, and acidity as indicators for evaluating the freshness of fishmeal.
1. Histamine is a biologically sensitive toxin and has a strong stimulatory effect on the digestive tract. It can cause gastrointestinal bleeding and erosion. It is also known as erodin. Histamine is the product of microbial decomposition of raw materials before processing. The higher the content of fishmeal histamine processed into fish that is rotted, the more likely it is to cause gastro-intestinal diseases in rabbits and cause death.
2. Products of volatile base nitrogen-based acid degradation. The higher the content, the more the amino acid is destroyed, especially methionine and tyrosine. Therefore, the nutritional value of fishmeal is greatly affected and its utilization rate is reduced.
3, acid value can evaluate the degree of fat oxidation in fish meal. The higher the acid value, the more severe the oxidation of fat. As a result, a large amount of unsaturated fatty acids are destroyed, the nutritional value of fishmeal is reduced, unpleasant odors are generated, and feed palatability is affected. Even a lot of harmful substances are produced, which endanger rabbits, reduce the resistance of rabbits, and are easy to infect other diseases. Mortality is increased.
Because of the salt content of fishmeal, it is easy to absorb moisture, mold, heat, and even cause spontaneous combustion and decrease the quality of fishmeal during the hot and humid season. The toxin produced by moldy fishmeal can easily cause serious damage to breeding rabbits. The female rabbits are not estrus, infertility, stillbirth, miscarriage, and even cause damage to the breeding system; so that the abnormality of spermatozoa, semen quality, and lack of libido in male rabbits are caused. Infant diseases such as intestinal disease, increased mortality, etc.