With the rapid development of the feed industry, the use of various feed additives is becoming more and more extensive, especially in ensuring the integrity of feed quality and increasing nutritional function, various additives have attracted more and more attention. Sodium diacetate not only has a strong ability to kill fungi as an antifungal agent to ensure that the feed is not mildew and spoilage, but also can play the role of an acidifier, effectively regulate the pH value of the livestock and poultry intestines, improve the activity of pepsin and digestive enzymes, improve the digestibility of protein, increase the palatability of livestock and poultry to feed, inhibit the growth of harmful bacteria, and is conducive to the growth of lactic acid bacteria, thereby reducing material consumption, improving feed utilization, has good economic benefits, and is a safe and multi-functional feed additive without side effects.

In the 70s of the 20th century, large-scale production and application of sodium diacetate began in foreign countries. It was first recognized by the U.S. Food and Drug Administration (FDA) in 1982. At present, the United States, Japan, Germany, France, the United Kingdom, Sweden, Italy, Canada and other countries, as well as the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) have approved sodium diacetate as a fungal inhibitor in food and feed additives, and has been widely used. China's Ministry of Health has taken it as a new variety of preservatives, and has been included in the list of 26 kinds of food and 14 kinds of feed mildew and preservatives officially approved by the state for use.

1. Properties of sodium diacetate

Sodium diacetate (SDA), also known as sodium diacetate or sodium diacetate, is a molecular compound of acetic acid and sodium acetate, chelated by short hydrogen bonds. The molecular formula is CH2COONa· CH3COOH·xH20, the molecular weight of anhydrous is 142.09, and the actual products contain an irregular amount of adsorption water and structural water. The appearance is a white crystalline solid, with a slight acetic acid odor, easy to absorb moisture, soluble in water (solubility in water is about 1 g/m L) and ethanol. The melting point is 96 °C, and it is heated to more than 150 °C to decompose, and it is flammable. It is very toxic, non-carcinogenic, and has no residue.

2. Nutritional properties of sodium diacetate

(1) Nutritional sodium diacetate can effectively increase the nutritional value of feed, reduce the ratio of feed to meat, improve the lean meat rate of fat pigs, increase the milk yield of dairy cows, and be used for forage silage and mildew prevention, which can improve the utilization rate of forage protein. For example, if the cows are fed with silage corn containing 0.05%~0.2% sodium diacetate, it is found that the milk yield is increased by 10.2%, and after feeding for 2 0 days, the fat content of milk is increased by 6%; The addition of 0.3% sodium diacetate to the feed can increase the lean meat rate of fattening pigs by 2%, and the egg production rate of broiler chickens by 4%; Sows fed with 2% sodium diacetate feed increased the number of litters from 2 to 3 times, and the addition of 0.025%~0.1% sodium diacetate to the pellet compound feed could increase the crude protein utilization rate by 11%.

(2) High efficiency Adding 0.15%~0.75% sodium diacetate solution to the newly harvested grain or feed can effectively prevent mildew. The antiseptic effect of sodium diacetate is better than that of propionate, which is widely used at present, and its addition amount is only 1/2~1/3 of propionate, and the price is only 2/3 of propionate (the current market price: propionate salt 15,000 yuan/ton; SDA 10,000 yuan/ton).

(3) Palatability The sour taste of sodium diacetate can cover the unpleasant smell of drugs and a variety of trace elements in the feed, thereby significantly enhancing the appetite of livestock and poultry, and improving the feed intake and daily weight gain of dairy cows and weaned piglets. Feeding dairy cows with silage corn containing 0.05%~0.2% sodium diacetate can increase their feed intake by 10%~20%; Sodium diacetate added to fish feed can increase the weight of carp by 6.15%~15.11% without polluting water quality.

(4) Safety The toxicity of sodium diacetate is very low, the oral LD50 of mice is 3.31 g/kg, the oral LD50 of rats is 4.96 g/kg, and the allowable intake per person per day (ADI) is 0 m g/kg~15 m g/kg. The final metabolite of sodium diacetate in the human body is carbon dioxide and water, no residue, no toxic side effects, and moderate intake of acetic acid is also beneficial to human and animal health. Therefore, sodium diacetate is a safe product and will become the preferred food, grain, and feed additive.

3. Application in animal husbandry

(1) For the storage of green fodder, it has a strong ability to kill fungi, can effectively inhibit the mildew of feed and cereals, add 0.2% ~ 0.4% sodium diacetate to the silage, can make the silage prolong the storage period at pH 4.0 for more than 3 weeks; add 0.2% sodium diacetate in the silage rye for mildew prevention test It was found that after 5 months of storage, the total number of mold in the test group was only one-tenth of that of the control group, and basically did not mold in the opening service cycle. Sodium diacetate also plays an important role in reducing grain decay during harvesting. According to the literature, the storage period of the grain was increased from 90 days to 208 days by adding 0.1%~0.8% sodium diacetate to the grain with a water content of 21.5%, and the mold growth inhibitor composed of sodium diacetate 77.6%, sodium sorbate 20% and anti-caking agent 2.4% was added to the grain with a relative moisture content of 17%~33%, and stored for 90 days at a temperature of 21 °C~ 27 °C and a relative humidity of 70%~80% without mold formation.

(2) Enhance the palatability of livestock and poultry to feed, and improve the feed utilization rate of sodium diacetate can enhance the palatability of dairy cows to feed and improve feed utilization. The feeding test of dairy cows showed that adding 0.1% ~ 0.15% sodium diacetate in silage can improve the feed intake of dairy cows, and the net energy, crude protein, calcium and phosphorus consumed per 1 kg of milk produced in the experimental group were 7.0%, 2.02%, 8.1% and 1.0% lower than that of the control group, respectively, which improved the feed utilization rate, reduced the production cost of dairy cows, and had certain economic benefits for the feeding of dairy cows.

(3) Increase the milk yield of dairy cows and the milk fat rate of milk, increase the lean meat rate of fattening pigs and the litter size of sows After sodium diacetate enters the cow's body, it increases the content of acetic acid in the cow body, improves the pH in the rumen, on the one hand, it is conducive to the formation of short-chain fatty acids in milk fat, and improves the milk fat rate of milk; on the other hand, it is conducive to the growth and reproduction of microorganisms in the rumen and the decomposition, digestion and absorption of various nutrients, and increases milk production. Feeding black and white cows with sodium diacetate The test showed that adding 0.1% ~ 0.2% sodium diacetate to the silage, the milk yield of each cow in the experimental group increased by 2.02 kg per day compared with the control group, and the milk yield increased by 10.2%, and it was found that after feeding for 20~40 days, the milk fat rate of the milk in the experimental group increased by 0.2% compared with the control group, and the milk fat rate increased by 6 percentage points, and the milk quality was improved by adding sodium diacetate. Feeding fattening pigs with 0.3% sodium diacetate in the feed can increase the lean meat rate by 2%, and feeding sows with 2% sodium diacetate can increase the annual litter size from 2 to 3 times.

(4) Sodium diacetate as a feed additive to feed chickens, can increase the economic benefits of raising chickens with sodium diacetate as a feed additive to feed chicks, broilers, adult laying hens, can inhibit mildew and prevent disease, improve the survival rate of chickens, promote weight gain, reduce the mortality rate of adult chickens, improve feed utilization rate and egg production rate, and increase the economic benefits of raising chickens. Adding 0.5% sodium diacetate to the feed of laying chicks can increase the feed utilization rate of 8-week-old chicks by 2.34 percentage points, and the survival rate at the end of 20 weeks of age can be increased by 9.01 percentage points; adding 0.5% to the feed of adult chickens can increase the egg production rate by 4.94 percentage points, the daily consumption of each chicken is reduced by 0.4g, and the egg-to-feed ratio is increased by 7.6%. 2 percentage points, the average weight increased by 4.8%, and the material consumption decreased by 4.3%; Adding 0.2% sodium diacetate to the diet of finishing chickens and laying hens has a significant effect on the prevention and control of chicken diarrhea, and can promote the growth of finishing chickens and improve the egg production rate;

4. Precautions in the application of sodium acetate (1) Pay attention to the preservation conditions sodium diacetate has hygroscopicity, more than 150 °C to decompose, therefore, it should be stored in a dry and cool place, the temperature is not higher than 40 °C, and in the processing process added to the feed, high temperature should be avoided to prevent the decomposition of sodium diacetate and reduce its use effect. (2) Pay attention to the correct way to use sodium diacetate, sodium diacetate should be added to water into a concentrated solution evenly sprinkled in the feed, it can also be fully mixed with other trace additives and then evenly mixed into the feed. Sodium diacetate is mixed with other anti-mildew preservatives such as calcium propionate, sodium benzoate, sodium sorbate, etc., which has a synergistic effect and makes it more stable. (3) Pay attention to the appropriate amount of addition as an anti-mildew preservative, when the moisture rises, the addition of sodium diacetate should be increased, and in the case of the same moisture content, the more the amount added, the longer the safe storage days. Under normal circumstances, the addition amount of sodium diacetate in feed and food is 0.1%~0.8%.