The potential threat to the aquatic feed is mainly the fungal toxin. At present, more and more studies have indicated that the harm of fungal toxin to aquaculture is similar to that of terrestrial species. Common mycotoxins mycotoxins are mainly yellow aspergillus toxin, CPA, ochratoxin A, deoxidation nivalenol, Fusarium toxins, such as. And aflatoxin is the most harmful to fish.
Corn is the main component of fish feed, it may also contain a fungal toxin, especially aflatoxin, content and even up to 6000ppb. The southeastern United States once 27% of the corn samples contain more than 400ppb of the fungal toxin, more than 50% of the samples exceeded 100ppb. Cottonseed Kernel, peanut kernel are the most susceptible to aflatoxin contamination, and feed production should as far as possible to avoid accept this kind of material. If you must use, to ensure that the raw material is not contaminated by aflatoxin, and to check all the feed. Cottonseed and corn are common ingredients in crabs and catfish, and 30% to 25 of the feed formula.
The serious hazard of aflatoxin in rainbow trout in the fish gill white, reduce the number of red blood cells, liver damage and so on. An American University found that catfish and other warm water fishes with rainbow trout than not easy infection of aflatoxin.
When catfish fed semi purified diets, if yellow aspergillus toxin containing up to 10 ppm, feeding for 10 weeks will show more obvious symptoms, such as decreased significantly growth rate, reduce the number of red blood cells and hemoglobin, liver necrosis, renal enlargement, gastric necrosis etc.. Salmon oral 12mg/kg (weight) of aflatoxin can lead to reflux of gastric content, into the peritoneal membrane of aflatoxin if more than 12ppm can cause hemoglobin content down to normal levels of 90%. It can lead to the necrosis of the intestinal mucosa and blood cells, so that the color of some organs become shallow. These side effects, in turn, lead to slow growth and poor feed efficiency.
Although studies on the effects of fungal toxins on shrimp are rare, some studies have suggested that the fungal toxins in the diet may affect the survival and growth of the shrimp. In Thailand and Philippines, studies have been carried out to detect the effect of fungal toxin levels on the culture. Histopathological studies have found that the damage of the B1 to the (chitosan) liver pancreas indicates that the fungal toxins in the shrimp feed can affect the yield. Philippines scholars found that the shrimp feed of the mold toxin concentration in 73.8ppb shrimp growth is slow, more susceptible to skin diseases, (chitosan), the liver and pancreas damage in other conditions will also lead to.
Chinese Academy of Fishery Sciences Yellow Sea Fisheries Research Institute; Meng Qing Liang, in the effects of aflatoxin on growth of Penaeus chinensis were found. The content of aflatoxin B1 in feed were 472.0ppb 78.7ppb. In control group is 100, the survival rate of Penaeus chinensis were for 55%, the rate of weight gain were 44% and 45%, digestibility, followed by the control group 79.4% and 83.2%. Shrimp swimming slowly, the individual shrimp in the water to swim, rarely hold food, leaving the water that is dead.
Montmorillonite has the effect of purifying water quality and reducing the harmful effects of toxic substances in water. It is widely known as water quality improvement agent, mainly in the following aspects:
1, the effective degradation of acid rain and dew rain toxicity, such as crab fish liver poisoning prevention.
2, reduce fish, shrimp, crab, shellfish in vivo drug residues, coordinating living organism of amino acid balance absorption, the fish, shrimp and crab shell bright color, delicious meat, improve product quality.
3, reduce the non nutrient deficiency (snails), spotted fish scales fall off, promote the growth of fish and shellfish.
4, quickly remove toxins crab fish and shellfish, improve immunity and restore normal feeding crabs. PH value of the bottom pool is stable and sustained release oxygen, increase the dissolved oxygen in the water and oxygen flow, can rise to adjust, supplement the role of trace elements in aquaculture, can effectively promote the body metabolism of fish and shrimp, resistance to disease, improve survival rate.
5, regulate water quality, enhance immunity, eliminate Tang Di rancidity and geological reasons caused by rust, iron, sulfur, ammonia standard substance containing; can significantly reduced decapod stress responses in the shelling, promote growth, improve the survival rate; can significantly reduce each net caused by the pool bottom silt caused by hydrogen sulfide and heavy metal toxic substances such as pan pond mud in toxicity.
6, elimination, degradation of surrounding waters caused by industrial wastewater discharge pond for heavy metals and toxic elements (mercury, antimony, arsenic, aluminum, etc.) for exceeding the pollution, creating good water quality of the environment, making the environment for the growth of fish and shrimp has been in good condition, and improve the yield of fish and shrimp.