Control Methods for Barley-Yellow Plague in Grass Carp Farming

“Barley yellow, White Dew heart” are the two key seasons when grass carp diseases occur at a high rate. At present, as air and water temperatures gradually rise, grass carp have also entered the season of high disease incidence.

Grass carp barley-yellow plague refers to the mass mortality of grass carp caused by mixed infection of the two major diseases, grass carp branchial necrosis and red skin disease, around the time of barley yellow. The obvious symptoms of this disease are: the tips of the gill filaments of diseased fish rot and are covered with mud, and the gill filaments become ischemic and whitish, forming mottled gills; the scales of diseased fish fall off, the body surface turns red, and in severe cases the fin rays appear worm-eaten and the fin bases rot. Grass carp barley-yellow plague is a highly contagious disease. If not treated in time, it can wipe out the entire stock of grass carp, ultimately causing failure in grass carp farming. Although grass carp barley-yellow plague is highly contagious, as long as preventive work is done scientifically, the disease can be kept under control: (1) Do a good job of water disinfection. Every 5-7 days, disinfect the water once by alternating dibromohydantoin, bromochlorohydantoin or Yudeli. (2) Scientifically administer oral medication. Once signs of disease are found in grass carp, choose drugs with good therapeutic effects (such as erythromycin specially for aquatic products) and feed continuously for 5-7 days. (3) Control the feeding amount. Grass carp have a greedy feeding habit, so the daily bait amount should be controlled below 3% of the fish body weight. (4) Combine grass with feed. Because green grass contains unknown growth factors that can promote the healthy growth of grass carp, when feeding complete compound feed, an appropriate amount of green grass can be added according to actual conditions to promote the growth of grass carp.