What is the impact of African classical swine fever on China's pig industry? What are the countermeasures?

Since August 3, 2018, there have been more than 110 cases of African classical swine fever in China, all over the country. The epidemic situation in major pig-raising provinces is relatively serious, and it has entered the post-African classical swine fever era. What is the impact of African classical swine fever on China's pig industry? Is there any way to deal with it?

I. the influence and challenge of African classical swine fever on China's pig industry.

1. African classical swine fever has caused a sharp decline in the stock of pigs

(1) directly lead to death and culling losses. The number of deaths in sick pig farms in Africa and the number of culls around the affected pig farms are about 1 million.

(2) there are serious losses in the implementation of inter-provincial embargo. After the occurrence of classical swine fever in Africa, in order to prevent the spread of the epidemic, the relevant departments banned the inter-provincial transportation of live pigs and breeding pigs, which affected the pig market and caused fluctuations in pig prices in different regions. There are few pig farming in southern provinces, pork supply exceeds demand and the price is high; the output value of the main pig producing areas is excessive and the price is low, which leads to the loss of pig raising enterprises and has to reduce the scale of pig breeding.

(3) the loss of breeding pig farm is huge. Most of China's pig breeding enterprises and core pig farms are concentrated in a few provinces, and breeding pigs are sold to the whole country. After the inter-provincial embargo, some breeding farms adopted self-breeding and no introduction in order to prevent and control African classical swine fever, resulting in poor sales of breeding pigs in pig farms, so they had to reduce their herds and reduce the scale of production. According to statistics, in February 2019, the stock of breeding pigs in 33 first-class purebred pig breeding farms in Shandong Province decreased by 41.2% compared with July 2018, and the sales volume of breeding pigs in the province decreased month by month, with a significant decline, and sales outside the province basically stagnated after September 2018.

(4) the malpractice of pig raising mode leads to the reduction of production scale. With the large-scale development of pig farms and a large amount of capital investment, pig-raising enterprises have implemented a detailed division of labor and changed the self-breeding mode to the breeding mode of companies plus farmers. The company focuses on raising sows, breeding and producing weaned piglets and selling them to farmers. This model has been pursued by large enterprises and has been developed rapidly. However, with the occurrence of African classical swine fever, the company's weaned piglets have no customers, and they have not built their own pig sheds for care and growth and fattening pigs, so they have to reduce the scale, reduce herd production or close pig farms.

(5) the decrease of pork sales leads to the depression of pig prices and the decrease of pig production. Sales of meat products have decreased due to consumers' panic about African classical swine fever and an increase in the inventory of pig slaughtering enterprises. According to the monthly report data of 189 pig slaughtering enterprises in Shandong Province, the slaughtering volume and sales volume of live pigs decreased significantly in February 2019 compared with January, and the inventory increased compared with the same period last year.

(6) the owners are in a panic and give up raising pigs or do not dare to raise pigs. After the outbreak of classical swine fever in Africa, the panic of farms (households) intensified and pigs were quickly sold. In many places, the weight of fattening pigs was only 90-95 kilograms, while in some places it was less than 90 kilograms. Farmers do not dare to fill the fence, since the breeding of self-breeding enterprises to adjust the sow herd no longer fill the fence, simple fattening farm after the stop of the phenomenon is also more common.

The market price of live pigs is too low, and farmers are reluctant to invest, especially when there is an epidemic in pig herds. When an epidemic occurs in nearby pig farms, they are afraid of being infected by their own pig farms and eliminate them.

At present, the pig industry is facing greater difficulties: first, the number of breeding pigs is reduced. The funding chain of pig breeding farms is tight, sales are stagnant, and the stock of breeding pigs is reduced, resulting in a serious damage to the subsequent supply capacity. Second, the number of hurdles is reduced. In the self-breeding farm, the stock of sows decreased, the fattening farm was not willing to fill the column, the wait-and-see attitude increased, the empty column increased, and the supply of fattening pigs decreased obviously in the later stage. Third, the price has gone up. In the short term, pig production and marketing basically maintain a balance, but the tight situation of pig supply and demand has emerged and existed for a long time, pork product prices may rise significantly.

In order to grasp the production capacity, production and marketing situation of live pigs in various places, the stable production and supply situation of live pigs in 2019 was studied and judged. In February 2019, the Animal Husbandry and Veterinary Bureau of the Ministry of Agriculture and villages and the National Animal Husbandry General Station conducted a special survey in six provinces and regions across the country, and each province was assigned a major pig production county with an epidemic and a major pig production county without an epidemic. The results show that: in January 2019, the stock of 68000 sows in Henan Province was reduced by 26% compared with the same period last year, and only about 4000 sows were kept in 10 enterprises, of which the stock of original breeds and ancestral sows decreased by 7300, a decrease of 91%. In January 2019, the stock of breeding sows in Guangdong Province decreased by 26% compared with the same period last year, among which the monitoring sites with larger declines were Dongan Town, Yangdong District, Yangjiang City (81% decline), Nanjing Village, Heshan City (81% decline), and Zhushan Town, Sanshui District, Foshan City (71%). In January 2019, the stock of live pigs in Jilin Province dropped by 28% compared with the same period last year, and the stock of fertile sows dropped by 23% compared with the same period last year; the stock of live pigs in fixed-point monitoring large-scale farms dropped by 15% year on year, and that of fertile sows decreased by 38% compared with the same period in 2018; the stock of live pigs in large counties decreased even more, with about 70, 000 Neng breeding sows in Gongzhuling City, nearly half less than in the same period in 2018, and about 100000 Neng breeding sows in Nong'an County, down 35% from the same period last year. In January 2019, the stock of live pigs in Jiangsu Province was 15.61 million, down 18.3 percent from the same period last year, and that of Neng breeding sows was 1.416 million, down 28 percent from the same period last year. According to the monitoring of 10 slaughterhouses that specialize in slaughtering sows, the slaughtering number of sows was 197800 in the fourth quarter of 2018, an increase of 47.33% over the same period last year, and 117000 in January 2019, an increase of 208% over the same period last year.

two。 Affect the layout of pig industry in China

For the overall development of the national economy and the protection of environmental health, the former Ministry of Agriculture issued the National Pig production Development Plan (2016-2020) on April 18, 2016, which puts forward a strategic plan for China's pig industry. Key development areas have been set up throughout the country: Henan Province, Chongqing Municipality, Sichuan Province, Hainan Province, Guangxi Zhuang Autonomous region, Hebei Province and Shandong Province. Potential growth regions: Liaoning, Jilin, Inner Mongolia Autonomous region, Yunnan, Guizhou and Heilongjiang provinces. Moderate development areas: Xinjiang Uygur Autonomous region, Xizang Autonomous region, Qinghai Province, Ningxia Hui Autonomous region, Shanxi Province, Shaanxi Province and Gansu Province. Restricted development areas: Beijing, Shanghai, Tianjin, Fujian, Anhui, Jiangxi, Hubei, Jiangsu, Zhejiang, Hunan, Guangdong and other southern water network areas.

The division of breeding areas and the increase of environmental protection pressure have led to the relocation of a large number of pig farms and a reduction in the number of pigs in the restricted development areas, while this region has dense population, developed economy and large demand for pork; the number and scale of pigs in key development areas are large, with a large amount of capital investment, it will inevitably lead to overcapacity. At present, the pattern of raising pigs from the south to the north and transferring pigs from the west to the east has been formed, and the ravage of classical swine fever in Africa has undoubtedly had a certain impact on its development. The eating habits of most regions in the south tend to be hot carcasses, while consumers in the north are keen on cold fresh meat. The outbreak of classical swine fever in Africa and the implementation of cross-regional embargoes have led to a contradiction between pig supply and demand, colliding with the regional division plan for breeding, and it is necessary to replan the layout of the domestic pig industry.

3. Affect the model of pig raising in China

In recent years, large-scale breeding companies have been adopting the settlement pig-raising model of leading enterprise groups integrating small and medium-sized farmers to develop industrialization, "company + family farm" and "core breeding pig farm + satellite fattening farm". A number of "aircraft carrier" pig groups have been established, and the pig industry has developed rapidly. African classical swine fever has brought certain security risks to this model, and relevant enterprises need to adjust their breeding methods and operation models, and the layout of national core pig breeding farms and first-class breeding pig farms also need to be reconsidered.

4. Affect the pattern of animal husbandry

At present, China's pig industry accounts for more than 50% of animal husbandry, and pork consumption accounts for more than 60% of meat consumption. African classical swine fever has shaken the confidence and willingness of pig farmers, so it is necessary to speed up the development of other livestock and poultry farming industries, promote the production and consumption of cattle, sheep and poultry, reduce consumers' over-dependence on pork, and change the breeding pattern of "pork dominating the world".

II. What are the countermeasures against African classical swine fever

1. Measures to enhance biosafety

As we all know, eliminating the source of infection, blocking the route of transmission and protecting susceptible animals are the three major elements to prevent and control the formation of infectious diseases. Biosafety is a production system that mainly cuts off the route of transmission, including good feeding methods and management to prevent the occurrence of diseases. The basic principle of establishing biosafety system of pig farm is: "give priority to raising, raising is more important than prevention, prevention is more important than treatment".

The main results are as follows: (1) "breeding" is the basis of biosafety, which can improve the insusceptibility of susceptible pigs. Over the years, with the occurrence of high fever, blue ear disease, diarrhea disease, African classical swine fever and other diseases, farmers should pay more attention to veterinary work, pig disease treatment and how to raise pigs. Feeding pigs is not equal to raising pigs. "raising" is nutrition, which is necessary for pig growth and production, plays an important role in the development of pig immune system, and needs high-quality diet to guarantee. Protection of susceptible animals can regulate the immune status of pigs through feed nutrition, so nutrition is not only the basis of biosafety, but also the basis of disease prevention.

The metabolism and production performance of the body as well as the development and function of the immune system are based on nutrients, and nutrition is the first factor in the external environment that affects the immunity of the body. The lack or excess of any nutrients (protein, fat, vitamins, minerals, etc.) will lead to a decline in immunity.

Protein and amino acids: protein deficiency can cause lymph node and thymus atrophy, decrease in the number of lymphocytes in blood, and decrease in complement titer. Methionine deficiency can cause thymus atrophy, threonine deficiency can inhibit the formation of Ig, and the production of T cells, B cells and antibodies; cysteine is involved in protecting cells from the harmful effects of reactive oxygen species and scavenging free radicals.

Fat: high-fat diets inhibit lymphocyte transformation, and excessive saturated fatty acids inhibit the phagocytosis of immune cells. Corn oil, flaxseed oil and cocoa oil rich in unsaturated fatty acids can increase antibody production.

Vitamins: vitamins are important nutrients to maintain the immune function of the body. Vitamin An is a factor involved in T cell activation. Vitamin A deficiency will block T cell activation and lead to the decrease of Ig level. At the same time, vitamin An also regulates the number of T cell differentiation subsets in lymphocytes and peripheral blood. Vitamin E can enhance the immunity of the body, it can enhance the phagocytosis of immune cells, reduce stress response, protect the lymphocyte membrane, and maintain the integrity of the immune system. Other vitamins, such as folic acid, pantothenic acid, riboflavin and choline, also have important effects on immunity.

Minerals: iron deficiency causes anemia, decreases serum complement activity and affects DNA and protein synthesis, but high copper increases the body's sensitivity to bacterial and parasite infections. Zinc deficiency can cause thymus atrophy, adrenal corticosterone increase, leukopenia. And its phagocytic activity is inhibited or even completely lost, but excessive zinc will also inhibit immunity. Selenium is an immune enhancer, selenium deficiency will cause lymphoid tissue necrosis. Chromium is a component of glucose tolerance factor, and the increase of chromium can promote the production of T and B cells.

Put an end to harmful substances such as mycotoxins and drug toxins in the diet. Mycotoxins (such as aflatoxin, zearalenone, fumarotoxin, etc.), heavy metals (such as mercury, arsenic, lead, etc.), industrial chemicals and pesticides are collectively referred to as immunotoxicants, which can poison and interfere with the normal physiological functions of the immune system of animals. Excessive intake will reduce the activity of immune tissues and organs and reduce the production of antibodies. In recent years, the incidence of sows is increasing, and the important reason is that sows have a large food intake and more mycotoxins accumulated in the body, which leads to chronic occurrence of porcine eperythrozoonosis and so on. Because pigs are in a state of sub-health, major epidemics are easy to occur.

Therefore, in the absence of African classical swine fever vaccine, dietary nutrition can improve the activity of antibodies, cytokines and immune cells (T cells, B cells), improve the ability of pigs to resist foreign diseases, and properly match diets and accurate nutrition. we should do a good job in the feed allocation of all kinds of pig herds to meet the growth and production needs of different pig breeds, cultivate healthy and healthy pigs, and reduce the susceptibility of pigs to African classical swine fever. Enhance the activity of immune cells and the defense ability of the body against pathogenic microorganisms, and improve the resistance of the body to diseases.

(2) "prevention" is the key to biosafety, which is to cut off the route of transmission between pathogens and susceptible pigs, including disinfection, isolation, immunity and so on. To do a good job in biological prevention and control, pig farms should strictly control the flow of people, logistics, cars and pigs, and establish a prevention and control system for rats, flies, mosquitoes, birds and snakes.

Disinfection is the most important epidemic prevention measure in pig farms. First, it is necessary to make a good disinfection plan and disinfection plan; second, it is necessary to strictly select disinfection drugs and determine the amount of disinfectant per square meter and dilution times according to the area of the disinfection site. The objects of disinfection include pig farm keepers and managers, as well as feed, veterinary drugs, vaccines, production tools and pig feces and urine entering the pig farm.

To do a good job of environmental control, the pig farm should be far away, isolated, blocked and transferred, and the pig farm should be independent, dry, transparent and exposed to sunlight.

Isolation is an effective method to keep susceptible pigs away from the source of disease and block the source of infection in pigs. Isolation facilities include site selection and construction, isolation houses, separate breeding, disinfection rooms, isolation bars, etc.; isolation measures include full entry and exit, early weaning, batch production, group production, pig group bathing, phased production and staff bathing, changing clothes, shoes, hand washing and so on.

Immunization is to enhance the immunity of the body by vaccination to achieve the purpose of resisting diseases. Although there is no African classical swine fever vaccine available, it is necessary to do a good job in the immunization of other common diseases. According to the actual epidemic situation of the pig farm, the epidemic characteristics of the epidemic disease in the area where the pig farm is located should be considered. combined with the type, age, feeding and management of pigs, interference of maternal antibodies, nature, type and immune route of vaccine and other factors and immune surveillance results, the immunization procedure suitable for this farm should be formulated, and the immunization procedure should be strictly carried out, and the immunization record and immunity detection should be carried out to ensure the effectiveness of immunity.

(3) "treatment" is a remedial measure after biosafety failure. African classical swine fever is a kind of viral infectious disease, and there is no effective drug to treat it.

two。 Strengthen the construction of self-breeding and self-raising pig farms

The epidemic situation of self-breeding pig farms is stable, and there is naturally no cross-infection. Therefore, it is necessary to strengthen the construction scale of self-breeding pig farms, strengthen the standardized management model, and reduce the risk of infection with African classical swine fever.

3. Raise awareness of prevention

Pig farm directors, veterinarians and all pig farmers should constantly strengthen learning and skills training, earnestly master prevention knowledge, understand the harmfulness of various epidemics, raise awareness of prevention, do not panic when they encounter suspected cases of classical swine fever in Africa, and deal with them scientifically.

4. Increase the frequency of monitoring

During the epidemic period of classical swine fever in Africa, farms should comprehensively and thoroughly investigate the sources and transmission routes of all diseases, set up a testing team with the veterinarian in charge as the responsible person, increase the frequency of monitoring, realize accurate testing, implement the testing registration system, and establish testing files. Track all suspected cases, carefully and carefully investigate the epidemic situation, and control the development of the epidemic as soon as possible in accordance with the principle of "early, fast, strict and small".

5. Strengthen the control and control of key links to block the transmission of the epidemic

Strengthen the supervision of the introduction of pigs, breeding pigs and their products, as well as the supervision of pig transport vehicles, prevent diseased pigs from high-risk areas to low-risk areas, prohibit the use of kitchen leftovers to feed pigs, and cut off the most likely transmission chain. African classical swine fever testing should be carried out in the slaughtering process to prevent the virus from flowing to the market with the pork.

Strengthen the supervision of smuggling pig products. Europe does not consume pigs in the water, and the price is cheap, while some people in our country are desperate to smuggle pigs into the water in order to make huge profits. According to United Nations trade statistics, since 2017, 12 European epidemic countries have exported more than 400,000 tons of risky pig products to Vietnam, South Korea, China and other countries, a considerable part of which have been smuggled into China. China has tested positive for African classical swine fever virus nucleic acid in a batch of tripe.

6. Strengthen the propaganda of African classical swine fever science knowledge and guide public opinion scientifically

Through the mainstream media to timely announce the occurrence of the epidemic and the progress of prevention and control work, organize experts and scholars to scientifically interpret the popular science knowledge and hot issues of classical swine fever in Africa, and carry out a variety of training activities for pig farmers and consumers in the whole society. boost the confidence of farmers and the public.