There is a high risk of fertilization in livestock manure under the soil contaminated by antibiotics.

As veterinary drugs and feed additives, antibiotics are widely used in livestock and poultry and animal husbandry all over the world. According to statistics, the annual use of veterinary antibiotics in China exceeded 6000 tons in 2000. However, about 60% to 90% of the antibiotics used in farmed animals are excreted in prototypes along with feces, urine and other excreta and applied into farmland soil as organic fertilizer. The exposure of veterinary antibiotics in the environment and the potential ecological and human health hazards have become the focus of research in recent years. Developed countries and regions such as the European Union, the United States, Canada, Japan and Australia have legislated to require pre-market registration of veterinary drugs to conduct environmental risk assessment.

In recent years, there are many reports about the pollution concentration of veterinary drugs in animal feces, soil, surface water and other environmental media, but there are few reports on ecological risk exposure assessment of veterinary drugs. In view of the blank situation of environmental management and ecological risk exposure assessment of veterinary drugs in China, in 2014, Dr. Wang Na and others of Nanjing Institute of Environmental Science of the Ministry of Environmental Protection published a study on the environmental exposure of veterinary antibiotics. They selected three typical veterinary drugs commonly used in China's breeding industry, sulfamethazine (SDM), oxytetracycline (0TC) and enrofloxacin (ENF), to study their environmental exposure assessment.

Since manure fertilization is the most important way of environmental exposure to veterinary drugs, the European Federation of Animal Health (FEDESA) first established the u-ni form method to predict the soil PEC of veterinary drugs, which has been cited by VICH's guidelines for Environmental risk Assessment of Veterinary drugs.

The study of Wang Na et al found that the PEC (soil predicted exposure level) of veterinary drug antibiotics in the feces of different farmed animals was pig manure, chicken manure and cow manure from high to low, and the residual PEC of the three veterinary drug antibiotics in feces was SDM, OTC and ENF. The fertilizer substrates of veterinary drug antibiotics pec from large to small were pig manure, chicken manure and cow manure, the soil with three veterinary drug antibiotics pig manure and cow manure was the largest, and the PEC from high to low was SDM, OTC and ENF, but the maximum PEC of chicken manure was ENF, SDM and OTC. The order of veterinary drug antibiotic pec from high to low in the water of different farmed animals was pig farm, chicken farm and cattle farm, and the PEC of SDM was significantly higher than that of OTC and ENF.

The study also pointed out that the influence of the analysis parameters on the final prediction results showed that the PEC results obtained by different animal types and administration regimens were very different, and the half-life of drugs in feces or soil and the storage time of feces were also the key factors affecting the prediction results.

There is an urgent need to control the abuse of antibiotics in aquaculture.

At present, the use of antibiotics in the breeding industry is relatively common, and some of them have gone far beyond the scope of antibacterial, resulting in drug resistance of bacteria, bringing new problems to the prevention and control of livestock and poultry diseases, as well as a threat to the safety of livestock products. it is urgent to attach great importance to and deal with it.

It is understood that the main reasons for the abuse of antibiotic drugs in the breeding industry are as follows: first, in order to prevent and control livestock epidemic diseases, farmers use a large number of antibiotics in the breeding process, and some farmers even feed livestock and poultry drugs in advance to prevent disease. In the daily drug supervision work, the author learned that the sales of antibiotic drugs are large in rural areas, and most of them are purchased by farmers, which far exceeds the demand for the treatment of animal diseases. Second, some feed production enterprises in order to highlight the efficacy of products, the use of antibiotics, resulting in farmers unknowingly continuous use of livestock out of the pen, resulting in antibiotic residues in food of animal origin. Third, the relevant laws and regulations and mandatory standards are not perfect, and supervision and punishment are weak. Although the measures for the Administration of prescription and over-the-counter drugs for Animals, which came into effect on March 1 last year, impose certain restrictions on the use of antibiotics in the aquaculture industry, the antibiotics used by farmers do not necessarily come from veterinary drugs, and there are obvious gaps in both regulations and regulations. Due to the lack of substantive punishment measures, the punishment is small, and the illegal cost is very low, which leads to the breeders and feed production enterprises to be fearless.

The abuse of antibiotics not only restricts the sustainable development of the aquaculture industry, but also causes food safety problems that need to be treated with great efforts.

First of all, we should establish and improve the monitoring system of antibiotic drug residues and bring the monitoring of antibiotic drugs into the track of the rule of law. All antibiotics should be listed as prescription drug management (whether for human or veterinary use), and production and sales should have complete purchase and sales records to facilitate supervision. Only by controlling the production and sale of antibiotics from the source can we really curb the abuse of antibiotics. Secondly, establish industry standards as soon as possible and improve the detection methods of antibiotic drug residues. Increase investment in technology and develop a rapid, accurate and simple detection method as soon as possible. At the same time, the farmers who abuse antibiotics should be punished and cracked down to increase the cost of breaking the law. Thirdly, we should increase the scientific and technological support of the poultry breeding industry, increase the support for the research of antibiotic substitutes, and actively guide farmers to give up feeding antibiotics and adopt alternative products for green farming. Finally, publicity and guidance should be strengthened to make the public correctly understand the harmfulness of abuse of antibiotics.