Talking about the main role of betaine in aquaculture
1. as a food attractant
In addition to relying on vision, fish feeding is also related to smell and taste. Although the artificial bait put into aquaculture has comprehensive nutrients, it is not enough to arouse the appetite of aquatic animals. Betaine has a unique sweetness and a sensitive umami taste for fish and shrimp, making it an ideal food attractant.
Adding 0.5% to 1.5% betaine to fish feed has a strong stimulating effect on the smell and taste of all crustaceans such as fish and shrimp, has strong appetite, improves feed palatability, and shortens feeding time. , Promote digestion and absorption, accelerate the growth of fish and shrimp, and avoid water pollution caused by feed waste.
Adding betaine to the feed shortened the feeding time of Macrobrachium rosenbergii by 1/3 to 1/2 and increased the feed intake. Betaine-containing feed has obvious feeding effect on carp and dace, but has no obvious feeding effect on grass carp. The food-attracting effect of betaine is also manifested in that it can enhance the taste sensation of other amino acids on fish and enhance the food-attracting effect of amino acids.
Betaine feed attractant has the functions of increasing appetite, enhancing disease resistance and immunity, and can solve the problem of diseased fish and shrimps' refusal to feed on bait and to compensate for the reduced food intake of fishes and shrimps under stress.
2. Relieve stress
Various stress responses seriously affect the feeding and growth of aquatic animals, reduce the survival rate, and even cause death. The addition of betaine to the feed can help improve the decline of aquatic animals' food intake under disease or stress, maintain nutrient intake, and alleviate certain conditions or stress responses.
Betaine helps salmon resist cold stress below 10°C, and is an ideal feed additive for certain fish to survive winter. The grass carp fry that have been transported over long distances were put into Pond A and Pond B under the same conditions. The grass carp feed in Pond A was supplemented with 0.3% betaine, and the grass carp feed in Pond B was not added with betaine. It was found that the grass carp fry in Pond A was in In the water, the fry were active and fast, and no fry was found to die; while the fry in Pond B were slow to eat, and the mortality rate was 4.5%, indicating that betaine has an anti-stress effect.
3. Regulate osmotic pressure balance
Betaine is a buffer substance for osmotic pressure shocks. It can be used as an osmotic protective agent for cells, which can improve the tolerance of biological cells to drought, high humidity, high salt and hypertonic environments, and prevent the loss of cell water and the entry of salts. Improve cell membrane Na-K pump function, stabilize enzyme activity and biological macromolecular function, to regulate tissue cell osmotic pressure and ion balance, maintain nutrient absorption function, enhance tolerance to osmotic pressure changes such as fish and shrimp, and improve the success rate.
The high concentration of inorganic salts in seawater is not conducive to the growth and survival of fish. The carp test shows that adding 1.5% betaine/amino acid to the bait can reduce the amount of water in the muscle of freshwater fish, delay the aging of the fish, and help maintain the electrolyte of the fish when the concentration of inorganic salts in the water increases (such as seawater). and osmotic pressure balance, so that freshwater fish can smoothly realize the transition to the seawater environment. Betaine is beneficial for marine organisms to maintain a lower salt concentration in the body, continuously replenish water, and play an osmotic adjustment role, enabling freshwater fish to adapt to the transition to a seawater environment.
4. Partially substituted choline
Choline is an essential nutrient for animals, and it can provide methyl groups in the body to participate in metabolic reactions. In recent years, studies have found that betaine can also provide methyl groups for the body, and the efficiency of betaine providing methyl groups is 2.3 times that of choline chloride, making it a more effective methyl donor. A certain amount of betaine can be added to replace part of choline in aquatic feed. For example, half of the choline requirement of rainbow trout must be met, and the remaining half can be replaced by betaine. When betaine was used to replace appropriate amount of choline chloride in the feed, the average body length of Macrobrachium rosenbergii increased by 27.63% and the feed coefficient decreased by 8% compared with the control group without substitution after 150 days.
5. Improve production performance
Betaine can promote the growth of fish and shrimp, enhance disease resistance and immunity, and improve the survival rate and feed conversion rate by attracting food. The addition of betaine has a significant effect on promoting the growth of juvenile fish and shrimp and improving the survival rate.
The weight gain of rainbow trout fed betaine increased by 23.5%, and the feed coefficient decreased by 14.01%; the weight gain of Atlantic salmon increased by 31.9%, and the feed coefficient decreased by 20.8%. Adding 0.3% to 0.5% betaine to the compound feed of 2-month-old carp, the daily gain was increased by 41% to 49%, and the feed coefficient was reduced by 14% to 24%. Adding 0.3% betaine pure product or compound product to the feed can obviously promote the growth of tilapia and reduce the bait coefficient. Adding 1.5% betaine to the river crab bait, the net weight gain of the river crab was increased by 95.3%, and the survival rate was increased by 38%, resulting in a faster growth rate and higher survival rate.
6. Prevent fatty liver
Betaine can improve the oxidation process of fatty acids in cell mitochondria, significantly increase the content of long-chain acylcarnitine and the ratio of long-chain acylcarnitine and free carnitine in muscle and liver, promote lipolysis, and reduce liver and body fat deposition , promote protein synthesis, redistribute carcass fat, reduce the incidence of fatty liver.
Betaine has a significant effect on reducing fatty liver of grass carp. When grass carp is fed compound feed for a long time without green feed supplement, adding betaine can well prevent fatty liver disease caused by nutritional deficiency.