How should epidemic prevention work on dairy farms be carried out?
The purpose of epidemic prevention is mainly twofold: first, to prevent the introduction of infectious diseases; second, when an infectious disease occurs, to eliminate it as quickly as possible and prevent it from spreading out. Epidemic prevention measures mainly include two aspects: first, routine preventive measures; second, elimination measures when an infectious disease occurs.
1) Routine preventive measures
① Strengthen the feeding and management of the cattle herd to improve the body resistance of dairy cows.
② Adhere to the principle of self-breeding and self-raising, and strictly control the introduction of dairy cows. When dairy cows must be introduced, they must be introduced from non-epidemic areas, with each animal individually checked, and origin quarantine must be effectively carried out; only those proven free of infectious diseases may be introduced. Before joining the herd, they must also be isolated and observed for two months. If necessary, another quarantine should be carried out, and only cattle proven free of infectious diseases may be mixed into the herd with the original cattle for feeding.
③ Establish a barrier and disinfection system for the cattle farm, and strictly control entry at the farm gate. The main gate of a dairy farm must not be unobstructed; barriers must be set up. Personnel and vehicles entering the farm must be disinfected. The disinfection pool should always maintain an effective concentration and quantity of disinfectant solution (such as 2% caustic soda or 4% Lysol solution). Personnel should wash their hands with 0.2% sodium hypochlorite or 0.1% peracetic acid.
④ Establish a regular disinfection system to cut off transmission routes. Dairy farms should carry out two major disinfections each year in spring and autumn. After careful cleaning and scrubbing, cow sheds, the surrounding environment, exercise yard ground, feed troughs and water troughs should be disinfected with disinfectant solutions such as 2% caustic soda solution, 10% lime milk, and 5% bleaching powder.
⑤ Establish regular quarantine and immunization systems, identify sources of infection, and protect healthy cattle herds. Dairy farms should carry out quarantine for brucellosis and tuberculosis twice each year in spring and autumn. Each year, one preventive injection of anthrax vaccine and two injections of foot-and-mouth disease vaccine should be carried out.
2) Elimination measures during an infectious disease outbreak
① Rapidly isolate sick cattle. When an infectious disease is found in cattle, they should be isolated immediately. During isolation, continue observation and diagnosis, and provide symptomatic treatment if necessary. Dedicated personnel should be assigned to feed and care for isolated sick cattle, using dedicated feeding equipment, and contact with the healthy cattle herd is prohibited.
② Report the epidemic situation promptly. When an infectious disease that should be reported is found, the epidemic situation should be reported promptly to the higher-level business department, with a detailed report of the species of sick animals, time and place of onset, number of affected animals, number of deaths, clinical symptoms, necropsy lesions, preliminary diagnosis name, and prevention and control measures already taken. When necessary, neighboring areas should be notified so as to jointly prevent and control it and prevent the spread of the disease.
③ Carry out comprehensive and thorough disinfection. Strict disinfection should be carried out for the cow shed where sick cattle are located, the places they have visited, and the equipment they have contacted. Feed contaminated by sick cattle should be destroyed after disinfection. Manure excreted by sick cattle should be concentrated at designated locations for stacking, fermentation and disinfection. At the same time, emergency disinfection should be carried out in other cow sheds.
④ Conduct clinical examination of each animal. Other cattle in the same cow shed or same group should be clinically examined one by one, and serological diagnosis should be carried out when necessary, so as to detect sick cattle as early as possible.
⑤ Emergency preventive vaccination. Emergency preventive vaccination should be carried out for apparently healthy cattle that have been examined multiple times with no clinical symptoms and negative serological diagnosis, in order to protect the healthy cattle herd.
⑥ Implement blockade as appropriate. When a seriously harmful infectious disease occurs, relevant government departments should be requested to delineate the epidemic area and epidemic point, and after approval, blockade should be implemented within a certain range to avoid the spread of the epidemic. Blockade actions should be decisive and rapid, the blockade range should not be too large, and blockade measures should be strict.
⑦ Properly handle sick animals. The carcasses of dead sick animals should be harmlessly treated and destroyed in accordance with the provisions of epidemic prevention law, by burning or deep burial. Seriously sick animals and those without treatment value should be promptly culled and handled, so as to eliminate the source of infection as early as possible.
The site of a newly built dairy farm should be selected in a place with flat terrain, facing the sun and sheltered from the wind, good drainage, sufficient water sources, no pollution, and where no infectious disease has ever occurred. A green belt should be set up around the cattle farm. The cattle farm should be divided into a management area, a production area, and a manure and sewage treatment area. The management area and production area should be located upwind, with a disinfection room and disinfection pool between them. When building cow sheds, the floor and walls should first be made of materials that are easy to disinfect, so as to facilitate thorough disinfection, and a good manure and urine discharge system should be provided. Clean roads and dirty roads on the cattle farm should be separated to avoid crossing. Sewage discharge should follow the principles of reduction, harmlessness and resource utilization.
General rules of epidemic prevention
1. Dairy farms should implement the policy of “putting prevention first and combining prevention with treatment”. The purpose of routine epidemic prevention on dairy farms is to prevent the introduction or occurrence of disease and to control the spread of infectious diseases and parasitic diseases.
2. Epidemic prevention measures: Dairy farms should establish an entry and exit registration system. Non-production personnel must not enter the production area, and visits should be declined. Employees entering the production area must wear work clothes, pass through the disinfection room, and wash and disinfect their hands before entering. Dairy farm employees must undergo a health check once a year. If they suffer from an infectious disease, they should be treated outside the farm in a timely manner and may only return to work after full recovery. Newly recruited employees must undergo a health check to confirm that they have no tuberculosis or other infectious diseases. Dairy farm employees must not move between workshops, and production tools in each workshop must not be used interchangeably. Dairy farms must not raise other livestock and poultry. In special circumstances where dogs need to be raised, management should be strengthened, and epidemic prevention and deworming treatment should be implemented. Livestock, poultry and their products are prohibited from being brought into the farm area.
3. Cattle manure should be piled at fixed points, and insecticides should be sprayed regularly to prevent mosquito and fly breeding. Dead cattle should be harmlessly treated, and the equipment and environment contacted by the carcasses should be cleaned and disinfected. Culled and sold cattle may only leave the farm after quarantine and obtaining a quarantine certificate. Cattle transport vehicles must undergo strict disinfection before entering designated areas for loading. When dairy cows are suspected of having an infectious disease or a virulent infectious disease appears on nearby farms, isolation, blockade and other emergency measures should be taken immediately.
Hygiene and disinfection
Hygiene and disinfection are important measures for cutting off the spread of epidemic diseases. Dairy farms should establish a hygiene and disinfection system to reduce the occurrence of diseases as much as possible.
1. Disinfectants: Disinfectants should be selected that are relatively safe for people, dairy cows and the environment, have no residual toxicity, do not damage equipment, do not harm the body surface of cattle, and do not produce harmful accumulation in cattle.
2. Disinfection methods: spray disinfection, immersion disinfection, ultraviolet disinfection, sprinkling disinfection, hot water disinfection.
3. Disinfection system: Establish a disinfection system to disinfect the environment of the breeding farm (community), cow sheds, equipment, externally purchased cattle, visiting personnel, and before production operations (milking, assisted delivery, breeding, injection treatment and any contact operations on dairy cows).
Immunization
Dairy farms should, in accordance with the requirements of the Animal Epidemic Prevention Law of the People's Republic of China and its supporting regulations, and in light of local actual conditions, carry out preventive vaccination for prescribed diseases and selected diseases, and pay attention to selecting suitable vaccines, immunization procedures and immunization methods.
Quarantine
Dairy farms should conduct regular quarantine for infectious diseases such as tuberculosis and brucellosis in accordance with relevant national regulations and the specific requirements of the local animal husbandry and veterinary authorities.
Dairy cow health care
1. Udder hygiene and health care: The udder should always be kept clean, and hidden dangers that may damage the udder should be removed. The water and towels used to wash the udder during milking must be clean. 0.03% bleaching powder or 3% to 4% sodium hypochlorite, etc. may be added to the water, and towels must be disinfected. After milking, each teat should immediately undergo medicated dipping, and 3% to 4% sodium hypochlorite (freshly prepared) may be used. Monitor subclinical mastitis 10 days before drying off. Positive or clinical mastitis must be treated. Monitor twice more 3 days before drying off, and only negative cows may be dried off. Milkers, milking machines and other tools must be cleaned and disinfected properly. Milk healthy cows first and sick cows afterward (with dedicated equipment). Dairy cows with severe mastitis may be culled and handled.
2. Hoof hygiene and health care: The floor of cow sheds and exercise yards should be kept flat, clean and dry. Keep cattle hooves clean, remove dirt between the toes, or wash with water (in summer). Regular disinfection must be adhered to. Use 4% copper sulfate solution for spray hoof bathing. In summer and autumn, disinfect once to twice every 5 to 7 days; in winter, the interval may be appropriately extended. Conduct a general survey of the limbs and hooves of the whole herd once a year, and uniformly trim cows with hoof deformation in spring and autumn. Treat cows with hoof disease promptly to promote recovery. Keep supplying a balanced diet to prevent laminitis.
3. Monitoring of nutritional and metabolic diseases: High-yielding cows should have blood samples taken for spot checks at drying off and about 10 days before calving to measure relevant physiological indicators. Ketone bodies should be monitored regularly: once every 1 to 2 days in the week before calving and within one month after calving, and treatment measures should be taken promptly if abnormalities are found. Strengthen monitoring of cows near calving. For high-yielding, weak cows with poor appetite, 20% calcium gluconate may be appropriately supplemented 1 to 3 times one week before calving to increase resistance. Pay attention to care during high yield in dairy cows. At peak milk production, 1.5% sodium bicarbonate may be added to the diet (mixed into concentrate). Each year, randomly sample 30 to 50 high-yielding cows for monitoring of blood calcium and blood phosphorus.
Guidelines for the use of veterinary drugs
1. It is prohibited to add veterinary drug varieties not approved by the national veterinary administrative department to feed and feed products, especially veterinary drugs such as hormone drugs affecting dairy cow reproduction, substances with estrogen-like functions, hypnotic sedatives and adrenergic drugs.
2. It is permitted to use Chinese medicinal materials and Chinese patent medicines that comply with regulations for the prevention and treatment of dairy cow diseases. It is permitted to use compliant supplementary drugs such as calcium, phosphorus, selenium and potassium, acid-base balance drugs, body fluid supplements, electrolyte supplements, blood volume supplements, anti-anemia drugs, vitamin drugs, adsorbents, laxatives, lubricants, acidifiers, local hemostatic drugs, astringents and digestants.
3. It is permitted to use antibacterial drugs, antiparasitic drugs and reproductive hormone drugs approved by the national veterinary drug authorities, but the prescribed route of administration, dosage, course of treatment and precautions must be strictly observed. The provisions on withdrawal periods must be strictly observed. For varieties without a specified withdrawal period, the provision that milk must be discarded for no less than 7 days should be observed. When antiparasitic drugs are used externally, care should be taken to avoid contaminating milk.
4. Use veterinary drugs acting on the nervous system, circulatory system, respiratory system and urinary system, and other veterinary drugs, with caution.
5. Establish and keep records of the immunization program for dairy cows; establish and keep treatment records for sick dairy cows, including the animal number or other identification of the sick dairy cow, time and symptoms of onset, process of therapeutic medication, treatment time, course of treatment, trade names and active ingredients of the drugs used.