Feed is essential in animal breeding, but because of the veterinary drug ingredients added to it, it must be used reasonably. If the food hygiene law is violated or the animal is slaughtered while the drug is still dormant, it will cause the primary ingredient in the feed to remain in animal food. This has laid hidden dangers to people’s lives and health. Therefore, it is necessary to detect veterinary drugs in feed. In animal breeding, the use of veterinary drugs in feed is to promote animal growth and prevent and control animal diseases. According to the current situation, the veterinary drugs with high efficiency, non-toxicity and less residue are the most promising. The following is a brief introduction to several common veterinary drugs suitable for animal growth that can be used for a long time.
Classification and use
According to the sources and ingredients of veterinary drugs, they can be divided into five categories: The first category is extracted from plants, such as organic acids, volatile oils, amino acids and so on. The second category comes from animals, and most of the ingredients used in medicine are animal organs or body fluids, many of which contain hormones or digestive enzymes. The third category comes from minerals, which contains a variety of mineral elements, such as sulfur, sodium chloride and so on. The fourth category is chemically synthesized drugs, which are familiar with antibacterial synergists, vitamins and so on. Category 5 is extracted from some microbes, such as antibiotics.
Veterinary drugs commonly used in feed
- Sulfonamides
Drugs such as aminobenzenesulfonamide structure belong to sulfonamides, which can be used to prevent or treat bacterial infections. In animal breeding, the most commonly added sulfonamides are sulfamethoxine, sulfamethazine, and sulfadimethoxine. However, even if they are effective for disease prevention and treatment, they can not be eaten for a long time, which may cause kidney damage in animals, and they are also common allergens, and even worse, they will cause cancer. Relevant departments have listed sulfonamides in the key monitoring list.
- Chloramphenicol
Antibiotic is a well-known term for most people. It is a broad-spectrum antibiotic extracted from Streptomyces. It is added to feed to treat and prevent various infectious diseases. Chloramphenicol antibiotics are also various, such as methamphenicol, chloramphenicol, etc. If such drugs accumulate in large quantities in humans or animals for a long time, they will have great side effects and even inhibit bone marrow hematopoiesis. Many countries have listed it as banned drugs.
- Macrolides
This kind of medicine belongs to weakly alkaline antibiotics, which is produced by Streptomyces and is a long-term inhibitor. The most representative is erythromycin. In recent years, roxithromycin, medicillin, and spiramycin have appeared on the market. Because it can promote the faster growth of animals and increase the economic benefits of breeding, in breeding animals, the scope of application is more extensive. After long-term consumption of animals, the amount of drugs in the body is accumulated to a certain extent, which will seriously damage the liver and kidney, and the residual concentration is too high. It will also produce toxic reactions to human beings who eat animal food, change the micro ecological environment in human body, and affect the harmony of human intestinal bacteria.
Detection technologies
There are many kinds of veterinary drugs in the feed, and people are inevitably worried. The detection of veterinary drug ingredients in feed has become the top priority of feed workers. The traditional detection technology of feed is also constantly updated and changed.
- Spectrophotometry
In the laboratory, spectrophotometry is often used to detect the content of Tylosa in feed premix. It is found that better light absorption can be obtained when the concentration is controlled in the range of 5.0 ~ 50 μg / mL. However, this test method has many limitations and can only be useful for a few veterinary drugs in simple matrix feeds. The instrument used in spectrophotometry detection is relatively simple, but the operator is very cumbersome, the accuracy of the sample is also very high, a little careless will be wrong, and only one can be measured at a time.
- Microbiological method
The microbiology method, also known as the cup-plate method, is mainly used to determine the content of fermentation antibiotics. This measurement method takes the antibacterial effect of antibiotics on microorganisms as the standard, which has great advantages. Its operation is basically consistent with the theory, it is very flexible, and only a small amount is required for detection. This method is widely used in various countries and has been determined as a legal method for the detection of antibiotics. The content of Enramycin in feed was detected by this method, and the tester found that the lowest quantity was 0.5 mg / kg. Although this detection technique is a bit obvious, the requirements are extremely strict. Errors in one of the details or improper operation will cause the entire experiment to fail. Therefore, this method should not be promoted vigorously.
- High performance liquid chromatography
High efficiency is one of the advantages of HPLC detection methods. It is widely used in the detection of veterinary drugs. In addition to its high efficiency, its resolution is very high, the detection results can come out quickly, the amount of samples needed is small, and it is also convenient to recycle. Therefore, this method is highly respected, and some industry standards are also based on this method. The instruments often used in this method are fluorescence detectors and ultraviolet light detectors. Compared with these two detection instruments, the spectral information provided by the diode array detector is more extensive, which greatly improves the reliability of the detection.
