The effect of rare earth feeding on fish is good.

Rare earth refers to the general name of 17 metal elements in the periodic table, including lanthanum, praseodymium, neodymium, cerium, samarium and so on. Among them, cerium accounts for 48%, lanthanum 25%, neodymium 16%, praseodymium 5%, samarium 2%, and other 12 elements 4%. In recent years, rare earth has become an important resource for national economy and national defense construction. Not only can it be widely used as an industrial vitamin in metallurgy, machinery, petroleum, chemical industry, light industry, electronics and other industries, but also can be used as micro-fertilizer in agricultural production. In fishery production, feeding rare earths to fish also has a very good effect.

According to the experiment, fish fed with rare earths can produce three major functions: first, it has the function of regulating fish metabolism, improving the utilization rate of feed, and speeding up the growth of fish; second, it has the function of killing bacteria, which can prevent and cure diseases, and improve the survival rate of fish fry, reduce the occurrence of fish diseases; third, it has the function of stimulating the growth of plankton in the water, which can increase the bait of filter-feeding fish and reduce the consumption of feed. Practice has proved that under the same conditions, after the fish are fed with rare earths, the survival rate of grass carp can be increased by 14.6% to 20.9%, the feed consumption rate can be reduced by 14.6%, and the feed efficiency and protein utilization rate can be increased by 5.2% and 5.1% respectively. The average yield of fresh fish per mu of water can be increased by about 33.5 kg.

There are three ways to feed fish with rare earths:

Spray on fish forage 10 days before harvesting fish forage, 50 kg rare earth solution of 300ppm per mu was sprayed evenly on the forage grass. In this way, the forage yield can be greatly increased and the waste of rare earths can be reduced. If the cut grass is used to feed the fish, the grass can be dried in the sun, then every 40 grams of rare earths and 20 kilograms of water are evenly sprayed on 300 kilograms and 500 kilograms of grass, and then put into the fish pond to feed the fish after the droplets dry.

For every 50 kg of fish concentrate, 40g of rare earth can be used, first dissolved with a little acid, then mixed with 0.5 kg of water, and then sprayed evenly on the concentrate with a sprayer, spraying and mixing evenly, and can also be made into expanded feed for fish if possible.

Put into the fish pond water 10 days before the peak of the outbreak of fish disease in the adult fish pond, or when signs of dead fish are found in the fish pond, 200 grams of rare earths can be used on the surface of the fish pond per mu, mixed with 50 kilograms of water and sprinkled throughout the pond. Fish living in such a body of water can not only prevent disease, but also promote growth.

In addition, rare earths can also be used for disinfection of fish fry before entering the pond. The method is: take 150 grams of rare earth, add 250 grams of salt, 50 kilograms of water, and soak the fish fry for 5 minutes.

Rare earths have no toxic accumulation effect on fish. After the fish are fed with rare earths, the content of rare earths in the fish is still much lower than the allowable content set by the state, and will not cause any adverse effects on human health. However, the feeding amount of rare earths can not be increased at will to reduce costs and give full play to the best benefits of rare earths.