Betaine is a kind of non nutritive additive. It is an artificially synthesized or extracted substance based on the chemical components contained in the most favorite animals and plants of aquatic animals. Food attractants are often composed of more than two kinds of compounds. These compounds have a synergistic effect on the feeding of aquatic animals. By stimulating the smell, taste and vision of aquatic animals, they can gather around the feed, accelerate the feeding, and increase the food intake.

The feeding time of Macrobrachium rosenbergii was shortened by 1/3~1/2 and the feeding amount was increased by adding betaine to the shrimp feed. The diet containing betaine has obvious feeding attraction effect on carp and mud carp, but has no obvious feeding attraction effect on grass carp. Betaine can also enhance the taste perception of other amino acids to fish and enhance the feeding attraction of amino acids. Betaine bait has the functions of improving appetite, enhancing disease resistance and immunity. Disease shrimp resist the drug bait and compensate for the reduced food intake of fish and shrimp under stress.

Choline is an essential nutrient in animals. It can provide methyl for the body in vivo, thus participating in metabolic reactions. In recent years, research has found that betaine can also provide methyl for the body. The efficiency of betaine in providing methyl is 2.3 times that of choline chloride, and it is a more effective methyl donor. When betaine was used to replace choline chloride in the feed, the average body length of Macrobrachium rosenbergii increased by 27.63% and the feed coefficient decreased by 8% after 150 days compared with the control group. Betaine can improve the oxidation process of fatty acids in cell mitochondria, significantly increase the content of long-chain acyl carnitine and the ratio of long-chain acyl carnitine to free carnitine in muscle and liver, promote fat decomposition, reduce fat deposition in liver and body, promote protein synthesis, redistribute carcass fat, and reduce the incidence rate of fatty liver.