How to choose pellet feed for river crab?

Feed accounts for about 70% of the production cost in river crab breeding. in view of the general rise in feed prices this year, farmers should pay more attention to the reasonable selection, scientific collocation and scientific feeding of feed, so as to maximize the use of feed and reduce waste.

In the use of feed, farmers should do a good job of "reducing cost and saving expenditure", but it should be noted that this does not mean to choose low-priced feed.

Feed cost per unit fish yield = feed coefficient × feed price

It can be seen that the feed cost per unit fish yield is determined by both feed coefficient and feed price.

There is a certain relationship between the growth rate of river crab and the quality of feed. Only when the nutrient elements in feed can meet the growth needs of river crab, can it be ensured that river crab grows at the most reasonable growth rate. However, the demand for feed quality and quality of river crab is different in different growth stages, and the demand for protein of young crab is higher than that of adult crab. The demand for protein is also different in different stages of adult crab culture. Therefore, it is necessary to make a reasonable choice of feed and adjust it in time, such as blindly buying high-grade feed in order to improve the insurance coefficient of river crab breeding, which may not only increase the breeding cost, but also may not be suitable for the nutritional needs of crabs. And blindly using low-grade feed is even more undesirable, because low-cost feed generally uses raw materials of poor quality, low digestion and utilization, high feed coefficient, slow growth of crabs and large feed consumption, which will eventually lead to a decline in breeding efficiency. In fact, in the choice of pellet feed, farmers can completely process their own feed, that is, by consulting relevant experts, in view of the specific conditions of their own breeding, design a scientific formula suitable for their own breeding objects for processing, in this way, not only the quality of feed is guaranteed, but also the cost is low.

Of course, when farmers are processing their own feed, it is very important to identify the quality of fishmeal. Fishmeal is the main protein source in traditional aquatic feed. The protein content of high-quality imported fishmeal is more than 60%, some as high as 70%, and the protein content of domestic high-quality fishmeal is more than 55%. It is also rich in essential amino acids, fatty acids, minerals, vitamins, digestible energy and other ingredients necessary for fish growth and breeding, and has good palatability. The quality of fish meal directly affects the growth and feed utilization efficiency of farmed species.

Fishmeal is usually divided into white fishmeal and red fishmeal. White fish meal is processed from cold water fish such as cod and flatfish, while the main raw materials of red fish meal include anchovy, sardines, anchovy, mackerel and other scraps of processed fish, fish and shrimp. The main factors affecting the quality of fishmeal are the species of raw fish, the freshness of raw materials, the temperature of processing, the quality of fat and the composition of microorganisms and so on. these factors will cause protein decomposition, lipid oxidation and rancidity and Maillard reaction of fishmeal in the process of processing, transportation and storage, resulting in some substances that are toxic or can not be absorbed and utilized by animals, thus reducing the freshness and nutritional value of fishmeal and affecting the feeding effect.

The fishmeal with good freshness is brown (red fishmeal) or gray-white (white fishmeal), the color is uniform and has normal fishy smell, while the fishmeal with abnormal smell, with halal flavor or rotten smell is the fishmeal with poor freshness. this discrimination method is simple and feasible, although it is lack of objectivity.