Generally, in a good culture environment, although there are many pathogens, prawns can still grow well, because there are various disease-resistant factors in normal prawns and there are three lines of defense to protect themselves:
The first line of defense is the crustacean and mucosa of shrimp, which can not only prevent pathogens from invading shrimp, but also their secretions have bactericidal effect;
The second line of defense is bactericidal substances in body fluids and phagocytes, small granular cells and granular cells in blood cells;
The third line of defense is immune system, antimicrobial factors, lectins and killer factors. When the pathogen enters the shrimp, it stimulates lymphocytes to produce a special protein against the pathogen, thus eliminating the pathogen. If the immunity of prawns decreases, causing bacteria to invade and infect, shrimp diseases will break out. In order to improve the immunity and disease resistance of prawns, they must be fed with nutritional drug bait as soon as they enter the market. The use of drug bait can stimulate the disease prevention function and vitality of shrimp, promote the metabolic activity of the body, enhance the active immunity, prevent the occurrence of shrimp diseases, and lay the foundation for high-health shrimp culture.
Therefore, feeding drug bait is an indispensable and important measure for shrimp culture. However, some farmers disagree with this, mainly because they don't understand the particularity of drug bait. Drug bait has different effects because of its different kinds, contents, properties and production technology. How to use drug bait reasonably according to local conditions is a practical problem that needs to be strengthened in the prevention and treatment of shrimp diseases, and it must not be ignored.
The content of this article comes from: Inspection and Identification of Species Resources by China Agricultural Publishing House.