What impact has African swine fever had on China's pig farming industry and what are the countermeasures?
Since August 3, 2018, more than 110 African swine fever incidents have occurred in China, spread across the whole country, with the epidemic being relatively severe in major pig-farming provinces, and we have entered the post-African swine fever era. So what impact has African swine fever had on China's pig farming industry? Are there any countermeasures?
I. The impact of and challenges posed by African swine fever to China's pig farming industry
1. African swine fever has caused a sharp decline in the number of live pigs on hand
(1) It directly causes losses from death and culling. In areas where African swine fever occurred, the number of pigs that died on affected farms and the number culled around affected farms totaled about more than 1 million head.
(2) The implementation of inter-provincial transport bans caused severe losses. After the outbreak of African swine fever, in order to prevent the spread of the epidemic, relevant departments banned the inter-provincial transport of live pigs and breeding pigs, which affected the live pig market and caused fluctuations in live pig prices in different regions. Southern provinces have relatively little pig farming, so pork supply fell short of demand and prices were high; major pig-producing areas had excess output and low prices, causing pig farming enterprises to suffer losses and forcing them to shrink their farming scale.
(3) Breeding pig farms suffered huge losses. Most of China's breeding pig enterprises and core pig farms are concentrated in a small number of provinces, and breeding pigs are sold nationwide. After the inter-provincial transport ban, some breeding farms, in order to prevent and control African swine fever, adopted self-breeding and self-raising and stopped introducing breeding stock, which led to poor sales of breeding pigs at breeding pig farms, leaving them no choice but to reduce and shrink their herds and cut production scale. According to statistics, in February 2019, the breeding pig inventory of 33 purebred pig multiplier farms at or above the first level in Shandong Province fell by 41.2% compared with July 2018, and the monthly sales volume of breeding pigs within the province declined month by month, with an obvious drop, while sales outside the province had basically stagnated since September 2018.
(4) The drawbacks of pig farming models led to a reduction in production scale. With the large-scale development of pig farms, large amounts of capital input, and pig farming enterprises implementing detailed division of labor, the model changed from mainly self-breeding and self-raising to a farming method of company plus farmers. Companies concentrated on raising sows, breeding and producing weaned piglets for sale to farmers to raise. This model had always been pursued by large enterprises and developed rapidly. However, with the outbreak of African swine fever, the weaned piglets bred by companies had no customers, and since they had not built nursery pig and growing-finishing pig housing themselves, they had no choice but to shrink scale, reduce herds, or close pig farms.
(5) Reduced pork sales led to depressed live pig prices and reduced live pig output. Because consumers had a sense of panic about African swine fever, and pig slaughtering enterprises had increased inventory, sales of meat products decreased. According to monthly report data from 189 pig slaughtering enterprises in Shandong Province, in February 2019, pig slaughter volume and sales volume declined significantly compared with January, while inventory increased year on year.
(6) Owners were panic-stricken and gave up pig farming or did not dare to farm pigs. After the outbreak of African swine fever, the panic among farms (households) intensified, and they quickly dumped pigs on hand. In many places, the weight of finished fattening pigs sent to slaughter was only 90-95 kg, and in some places even less than 90 kg. Farmers did not dare to restock. Enterprises that bred and raised their own pigs no longer restocked after adjusting sow herds, and it was also fairly common for pure fattening farms to stop restocking after sending pigs to slaughter.
Live pig market prices were too low, and farmers were unwilling to invest, especially when an epidemic occurred in the herd, they were even more unwilling to spend on medication and treatment; when an epidemic occurred on nearby pig farms, they culled their herds for fear that their own farms would become infected.
At present, the live pig industry faces relatively great difficulties: First, the number of breeding pigs has decreased. Breeding pig farms are under tight cash flow pressure, sales have stagnated, and breeding pig inventories have declined, severely damaging subsequent supply capacity. Second, the number sent to slaughter has decreased. The inventory of breeding sows on self-breeding and self-raising farms has declined, pure fattening farms have weak willingness to restock, their wait-and-see attitude has deepened, and empty pens have increased, so the supply of fattening pigs in the later period will decrease significantly. Third, prices have risen. In the short term, live pig production and sales are basically balanced, but the tight supply-demand situation for live pigs has already emerged and will persist for a long time, and pork product prices may rise considerably.
In order to understand live pig production capacity and production and sales conditions in various places and assess the situation for stable production and supply guarantees for live pigs in 2019, in February 2019, the Animal Husbandry and Veterinary Bureau of the Ministry of Agriculture and Rural Affairs and the National Animal Husbandry Station conducted special research in 6 provinces and autonomous regions nationwide, selecting from each province and region one major pig-producing county where an epidemic had occurred and one major pig-producing county where no epidemic had occurred. The research results showed that in January 2019, Henan Province had 68,000 breeding sows on hand, a year-on-year decrease of 26%; 10 enterprises had only about 4,000 breeding sows on hand, among which the inventory of original breeding and grandparent-generation breeding sows decreased by 7,300 head, a reduction of as high as 91%. In January 2019, Guangdong Province's breeding sow inventory fell by 26% year on year, among which the monitoring points with larger declines were Dong'an Town, Yangdong District, Yangjiang City (decline of 81%), Nanjing Village, Heshan City (decline of 81%), and Zhushan Town, Sanshui District, Foshan City (decline of 71%). In January 2019, Jilin Province's fixed-point monitoring showed live pig inventory fell by 28% year on year, and breeding sow inventory fell by 23% year on year; fixed-point monitoring of large-scale farms showed live pig inventory fell by 15% year on year, and breeding sow inventory fell by 38% year on year; the decline in inventory in major pig transfer-out counties was even greater. Gongzhuling City had about 70,000 breeding sows on hand, nearly half fewer than in the same period of 2018; Nong'an County had about 100,000 breeding sows on hand, a year-on-year decrease of 35%. In January 2019, Jiangsu Province had 15.61 million live pigs on hand, a year-on-year decrease of 18.3%; breeding sow inventory was 1.416 million head, a year-on-year decrease of 28%. According to monitoring of 10 slaughterhouses specializing in slaughtering sows, in the fourth quarter of 2018 the sow slaughter volume was 197,800 head, a year-on-year increase of 47.33%; in January 2019 the sow slaughter volume was 117,000 head, a year-on-year increase of 208%.
2. It affects the layout of China's pig farming industry
For the overall development of the national economy and the protection of environmental sanitation, the former Ministry of Agriculture issued the National Live Pig Production Development Plan (2016-2020) on April 18, 2016, proposing a strategic plan for China's pig farming industry and establishing key development regions nationwide: Henan Province, Chongqing Municipality, Sichuan Province, Hainan Province, Guangxi Zhuang Autonomous Region, Hebei Province and Shandong Province. Potential growth regions: Liaoning Province, Jilin Province, Inner Mongolia Autonomous Region, Yunnan Province, Guizhou Province and Heilongjiang Province. Moderate development regions: Xinjiang Uygur Autonomous Region, Tibet Autonomous Region, Qinghai Province, Ningxia Hui Autonomous Region, Shanxi Province, Shaanxi Province and Gansu Province. Restricted development regions: Beijing Municipality, Shanghai Municipality, Tianjin Municipality, Fujian Province, Anhui Province, Jiangxi Province, Hubei Province, Jiangsu Province, Zhejiang Province, Hunan Province, Guangdong Province and other southern water-network areas.
The division of farming regions and increasing environmental protection pressure led to large numbers of pig farms in restricted development regions relocating outward and a reduction in the number of live pigs, yet these regions are densely populated and economically developed, with a large demand for pork; key development regions had more pigs and larger scale, and with large amounts of capital input, overcapacity was inevitable. At present, a pattern has already formed in which pigs are raised in the north for the south and pigs from the west are transported to the east, and the rampage of African swine fever has undoubtedly brought certain effects to its development. Most southern regions tend to prefer hot carcasses in their dietary habits, while northern consumers are keen on chilled fresh meat. The outbreak of African swine fever and the implementation of cross-regional transport bans created a contradiction between live pig supply and demand, clashed with the farming region division plan, and required re-planning of the domestic pig farming layout.
3. It affects China's pig farming model
In recent years, large-scale farming companies have consistently adopted a settlement-style pig farming model in which leading enterprise groups integrate small and medium-sized farmers for industrialization, with “company + family farm” and “core breeding pig farm + satellite fattening farm” models, forming many “aircraft-carrier-level” pig farming groups, and the pig farming industry developed rapidly. African swine fever brought certain safety hazards to this model, and relevant enterprises need to adjust their farming methods and operating models. The layout of national core breeding pig farms and first-level breeding pig farms also needs to be reconsidered.
4. It affects the livestock farming pattern
At present, China's pig farming industry accounts for more than 50% of the livestock industry, and pork consumption accounts for more than 60% of meat consumption. African swine fever shook pig farmers' confidence and willingness to restock, so it is necessary to accelerate the development of other livestock and poultry farming industries, promote the production and consumption of beef, mutton and poultry meat, reduce consumers' excessive dependence on pork, and change the farming pattern in which “pork dominates everything.”
II. What countermeasures are there against African swine fever
1. Improve biosecurity measures
As is well known, eliminating the source of infection, blocking transmission routes and protecting susceptible animals are the three major elements in preventing and controlling the formation of infectious diseases. Biosecurity is a production system for preventing disease occurrence that focuses on cutting off transmission routes and includes good feeding methods and management. The basic principles for establishing a pig farm biosecurity system are: “give priority to raising, raising is more important than prevention, and prevention is more important than treatment.”
(1) “Raising” is the foundation of biosecurity and can increase the resistance of susceptible pig herds. Over the years, with the occurrence of diseases such as high fever disease, blue ear disease, diarrheal disease and African swine fever, farmers should pay more attention to veterinary work, pig disease treatment and the question of how to raise pigs. Feeding pigs is not the same as raising pigs. “Raising” refers to nutrition, which is necessary for the growth and production of pig herds and plays an important role in the development of the pig immune system, and needs to be guaranteed by high-quality diets. Protecting susceptible animals can regulate the immune status of live pigs through feed nutrition, so nutrition is the foundation of biosecurity and also the foundation of disease prevention and control.
Body metabolism and production performance, as well as immune system development and function, are based on nutrients, and nutrition is the first factor in the external environment affecting the body's immunity. A deficiency or excess of any nutrient (protein, fat, vitamins, minerals, etc.) will lead to decreased immunity.
Protein and amino acids: protein deficiency can cause atrophy of lymph nodes and the thymus, a decrease in the number of lymphocytes in the blood, and a reduction in complement titer. Methionine deficiency can cause thymic atrophy, threonine deficiency inhibits Ig formation as well as the production of T cells, B cells and antibodies; cysteine participates in protecting cells from reactive oxygen species and in eliminating the harmful effects of free radicals.
Fat: high-fat diets inhibit lymphocyte transformation, and excessive saturated fatty acids inhibit the phagocytosis of immune cells. Corn oil, linseed oil and cocoa butter rich in unsaturated fatty acids can increase antibody production.
Vitamins: vitamins are important nutrients for maintaining the body's immune function. Vitamin A is a participating factor in T cell activation, and vitamin A deficiency can block T cell activation and lead to decreased Ig levels; at the same time, vitamin A also regulates the number of T cell differentiation subsets in lymphocytes and peripheral blood. Vitamin E can enhance the body's immunity; it can strengthen the phagocytosis of immune cells, reduce stress responses, protect lymphocyte membranes, 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, decreased serum complement activity, and affects DNA and protein synthesis; however, high copper increases the body's sensitivity to bacterial and parasitic infections. Zinc deficiency can cause thymic atrophy, increased adrenal corticosterone, and reduced white blood cells, and can inhibit or even completely eliminate their phagocytic activity; however, excessive zinc can also suppress immunity. Selenium is an immune promoter, and selenium deficiency can cause necrosis of lymphoid tissue. Chromium is a component of glucose tolerance factor, and increasing chromium can promote the production of T cells and B cells.
Eliminate harmful substances such as mycotoxins and drug toxins in diets. Mycotoxins (such as aflatoxin, zearalenone, fumonisin, etc.), heavy metals (such as mercury, arsenic, lead, etc.), industrial chemicals, insecticides and the like are collectively called immunotoxicants, and can poison and interfere with the normal physiological functions of the animal body's immune system. Excessive intake will reduce the activity of immune tissues and organs and reduce antibody production. In recent years, there have been more and more cases of disease in sows, and an important reason is that sows have a relatively large feed intake, so more mycotoxins accumulate in the body, leading to chronic occurrence of diseases such as porcine eperythrozoonosis. Because the pig herd is in a sub-healthy state, major epidemics are likely to occur.
Therefore, in the absence of an African swine fever vaccine, by improving the activity of antibodies, cytokines and immune cells (T cells, B cells) through dietary nutrition, the pig herd's ability to resist external diseases can be improved. Diets should be reasonably matched, nutrition should be precise, and feed formulation work for various pig herds should be effectively carried out to meet the growth and production needs of different pig breeds, cultivate healthy and robust pig herds, reduce the susceptibility of pig herds to African swine fever, enhance the activity of the body's immune cells and the body's defense ability against pathogenic microorganisms, and improve the body's resistance to disease.
(2) “Prevention” is the key to biosecurity and means cutting off the transmission routes between pathogens and susceptible pig herds, including disinfection, isolation and immunization. To do a good job in biosecurity prevention and control, pig farms must strictly control the flow of people, materials, vehicles and pigs, and establish prevention and control systems against rats, flies, mosquitoes, birds and snakes.
Disinfection is the most important epidemic prevention measure on pig farms. First, disinfection plans and disinfection schemes must be well made; second, disinfectants must be strictly selected, and the amount of disinfectant per square meter and the dilution ratio must be determined according to the area of the disinfection site. Targets of disinfection include pig farm keepers and managers, as well as feed, veterinary drugs, vaccines, production tools and pig manure and urine entering the pig farm.
Environmental control should be well carried out. Outside the pig farm, it is necessary to keep distance, isolate, block and transfer; inside the pig farm, it is necessary to ensure independence, dryness, ventilation and sunlight exposure.
Isolation is an effective method to keep susceptible pig herds away from sources of disease and block infection of pig herds by sources of disease. Isolation facilities include site selection and farm construction, isolation barns, separate barn feeding, disinfection rooms and isolation pens; isolation measures include all-in-all-out, early weaning, batch production, transferred-group production, showering when pigs are moved between groups, phased production, and staff showering, changing clothes, changing shoes and washing hands.
Immunization is the enhancement of the body's immunity through vaccination to achieve resistance to disease. Although no African swine fever vaccine is currently available, immunization work for other common diseases should be well carried out. Based on the actual epidemic situation on the pig farm itself, considering the epidemic characteristics of the region where the pig farm is located, and combining factors such as pig herd type, age, feeding management, interference from maternal antibodies, and the nature, type and route of immunization of vaccines, as well as immune monitoring results, an immunization program suitable for the farm should be formulated, and immunization procedures should be strictly implemented, with immunization records and immune testing well done to ensure effective immunization.
(3) “Treatment” is a remedial measure after biosecurity failure. African swine fever is a type of viral infectious disease, and there is currently no effective drug that can treat it.
2. Strengthen the construction of self-breeding and self-raising pig farms
Self-breeding and self-raising pig farms have stable epidemic conditions and naturally will not experience cross-infection. Therefore, it is necessary to strengthen the construction scale of self-breeding and self-raising pig farms and strengthen standardized management models to reduce the risk of African swine fever infection.
3. Raise awareness of prevention
Pig farm managers, veterinarians and all pig farming personnel should continuously strengthen learning and skills training, effectively master prevention knowledge, understand the harmfulness of various epidemics, raise awareness of prevention, and respond scientifically without panic when encountering suspected African swine fever cases.
4. Increase monitoring frequency
During the African swine fever epidemic period, farms should comprehensively investigate all sources and transmission routes of all diseases, establish a testing team with the veterinarian in charge as the responsible person, increase monitoring frequency, achieve precise testing, implement a testing registration system, establish testing files, track all suspected cases, and carefully and thoroughly investigate the epidemic. Once discovered, follow the principle of “early, fast, strict and small” to control the development of the epidemic as early as possible.
5. Strengthen control of key links and block transmission routes of the epidemic
Strengthen supervision over the introduction of live pigs, breeding pigs and their products and over pig transport vehicles, prevent diseased pigs from flowing from high-risk areas to low-risk areas, prohibit the use of kitchen waste to feed pigs, and cut off the most likely transmission chain. African swine fever testing should be carried out in the slaughtering process to avoid the virus flowing into the market with pork.
Strengthen supervision of smuggled pig products. Europe does not consume pig offal, and prices are cheap, while in China some people, for rich profits, take risks to smuggle pig offal. According to United Nations trade data statistics, since 2017, 12 epidemic-affected countries in Europe have exported more than 400,000 tons of risky pig products to countries such as Vietnam, South Korea and China, and a considerable portion of these entered China through smuggling. In a batch of pig tripe seized in China, nucleic acid positive for African swine fever virus has already been detected.
6. Strengthen publicity of scientific knowledge about African swine fever and scientifically guide public opinion
Through mainstream media, promptly publish information on the occurrence of the epidemic and the progress of prevention and control work, organize experts and scholars to provide scientific interpretations of scientific knowledge and hot issues concerning African swine fever, and carry out various training activities for pig farmers and consumers across society to boost the confidence of farmers and the public.