Feeding fish rare earth works well; fish farmers may want to give it a try

Rare earth refers to the collective term for the 17 metallic elements of the lanthanide series in the periodic table, including lanthanum, praseodymium, neodymium, cerium, samarium, and others. Among them, cerium accounts for 48%, lanthanum 25%, neodymium 16%, praseodymium 5%, samarium 2%, and the other 12 elements 4%. In recent years, rare earth has become an important resource for the national economy and national defense construction. It can not only be widely used as an industrial vitamin in metallurgy, machinery, petroleum, chemicals, light industry, electronics and other industries, but can also be used as a micro-fertilizer in agricultural production. In fishery production, feeding rare earth to fish also has very good results.

According to experiments, feeding rare earth to fish can produce three major functions: first, it regulates fish metabolism, improves the utilization rate of feed by fish, and speeds up fish growth; second, it kills pathogens, can prevent and treat disease, raises the survival rate of fry, and reduces the occurrence of fish diseases; third, it stimulates the growth of plankton in the water, can increase the food for filter-feeding fish, and reduces feed consumption. Practice has already proven that under the same conditions, after feeding rare earth to fish, the survival rate of grass carp can increase by 14.6%-20.9%, feed consumption can decrease by 14.6%, feed efficiency and protein utilization can increase by 5.2% and 5.1% respectively, and the average yield of fresh fish per mu of water surface can increase by about 33.5 kg.

There are three ways to feed rare earth to fish:

Spraying on fish forage grass: 10 days before harvesting the fish forage grass, use 50 kg of a 300 ppm rare earth solution per mu and spray it evenly onto the forage grass. In this way, the forage grass yield can be greatly increased and waste of rare earth can be reduced. If cut green grass is used to feed fish, the green grass can be spread under the sun to dry a little, then, based on 40 g of rare earth, mix with 20 kg of water and spray it evenly onto 300-500 kg of green grass; after the water droplets dry, put it into the fish pond to feed the fish.

Mixing into fish concentrate feed: for every 50 kg of fish concentrate feed, 40-50 g of rare earth can be used. First dissolve it with a small amount of acid, then mix with 0.5 kg of water, then use a sprayer to spray it evenly onto the concentrate feed, stirring evenly while spraying. If conditions permit, it can also be made into extruded fish feed.

Applying into fish pond water: 10 days before the peak outbreak of fish diseases in adult fish ponds, or when signs of dead fish are found in the fish pond, use 200 g of rare earth per mu of fish pond water surface, mix with 50-100 kg of water, and splash it over the whole pond. Fish living in such water can both prevent disease and promote growth.

In addition, rare earth can also be used for disinfection of fry before they are put into the pond. The method is: take 150 g of rare earth, add 250 g of table salt, mix with 50 kg of water, put the fry into it and soak for 5 minutes.

Rare earth has no toxic accumulation effect on fish. After fish are fed rare earth, the content of rare earth in the fish body is still greatly lower than the permitted content stipulated by the state, and will not cause any adverse effects on human health. However, the amount of rare earth fed cannot be increased at will; this is to reduce costs and give play to the best benefits of rare earth.