What Are the Causes of Mad Cow Disease?

Mad Cow Disease, also known as Bovine Spongiform Encephali-tis (BSE), is one of the animal species of Transmissible Spongiform Encephalitis (TSE). Mad cow disease is a subacute progressive neurological disease caused by prions. Usually, brain cells appear vacuoles, astrocytes proliferate, amyloid protein fibers are found in the brain, and systemic symptoms are accompanied by long latency and death It is characterized by high rate and strong infectivity. Since the disease was first discovered in the United Kingdom in 1985, it has gradually spread around the world, posing a huge threat to the cattle industry, the catering industry, and the safety of human life. The mid-1980s to the mid-1990s was the epidemic period. As of 2004, there were 179,000 sick cows diagnosed in the UK alone, involving 35181 farms. More than 11 million sick cows were slaughtered and burned. Tens of billions of pounds. For more than 20 years, BSE has spread to 31 countries in Europe, the Americas and Asia, and more than 100 countries have been affected by BSE, causing huge economic losses and social panic. ^[1]

BSE can be manifested as neurological and systemic symptoms, which often appear earlier than systemic symptoms. Common neurological symptoms include abnormal behavior, ataxia, and hypersensitivity. Behavioral abnormalities are mainly stray solitude, anxiety, fear, violent or depression, delirium, involuntary movements (such as molars, muscle twitches, tremors and spasms, etc.), unwillingness to pass through the concrete floor, turning, entering the corral, passing through the door Or milking. Aggressive behaviors often occur when sick animals approach or chase, which is also an important reason for their commonly known as mad cow disease. ^[1]

Early research has failed to isolate the pathogens of mad cow disease and other related diseases, and has not detected an immune response associated with the infection. Although hypotheses such as pesticides and autoimmune reactions have been proposed, none of these theories can explain the characteristics of the pathogen of BSE. In the 1980s, the American biologist Prucena discovered in the study of Mad Cow Disease that the infection of Mad Cow Disease is entirely prion (also known as prion protein), a peculiar nucleic acid-free protein that infects particles. RNA or DNA. ^[1]

The pathogenesis of BSE is mainly caused by the digestive tract, and due to the peculiar nature of prion protein, antibody vaccines cannot be used for effective preventive treatment at this stage. Therefore, the current prevention and control measures for mad cow disease are mainly to block the transmission route and eliminate the source of infection. Most countries have adopted the prevention and control of cattle herds, feed, slaughter products, etc. to avoid the potential hidden dangers of prion protein and the scattered disease of mad cow disease. ^[3]

Mad Cow Disease EU Safety Management

In 2001, the European Union established a comprehensive quality control management agency, the European Food Safety Authority, which is mainly responsible for monitoring the entire food chain. The European Union has issued a series of regulations on BSE control and feed safety, which can be summarized to include the following 4 aspects: (1) BSE passive monitoring and active detection plan and hunting policy; (2) elimination of designated risk substances (SRM); (3) ) Destroy safe substances safely; (4) Ban on animal-derived feed. ^[4]

The European Union has strengthened the quality and safety control standards for livestock products and implemented a strict and unified quality and safety system. The European Union began to implement the HACCP system in 1996 and stipulated in the EU Food Sanitation Law, requiring animal product production and processing companies to recognize that all aspects of production should pay attention to quality and safety, and to ensure that the HACCP system is established, implemented, and maintained And revise appropriate animal product safety measures. In response to the problem of mad cow disease, the European Union gradually established a food information traceability system in 1997 as an important means of quality and safety control of livestock products. According to the European Union's "Food Law", food, feed, livestock for food manufacturing, and articles related to food and feed manufacturing must establish a food information traceability system at all stages of production, processing, and distribution. ^[4]

BSE Safety Management in Canada

Canada passed the Canadian Food Inspection Agency Act in 1997 and established the Canadian Food Inspection Agency to exercise unified food safety supervision and enforcement powers including feed and livestock products, a food safety accreditation program for on-farm farms, and a plan to prevent mad cow disease. ^[4]

Mad Cow Disease Safety Management in the United States

The main safety measures in the United States are: sound animal product quality and safety laws, regulations, and standard systems; full-process control over the production, processing, storage, transportation, and sales of animal products; a strict organizational system for animal product quality and safety management; and strengthening production sources Control and import and export quarantine. The United States Congress has passed laws to ensure food quality and safety. The establishment of a quality standard system is an important measure to ensure the quality and safety of livestock products. ^[4]

Mad cow disease Dutch security system

The main measures for the implementation of cow health and health records in the Netherlands are: each cow must have a health certificate (mandatory), regular disease control and quarantine, and monitoring of cow registration (mandatory). There are specific regulations and requirements for feedstuffs. Only companies that meet IS09002 quality management standards and HACCP technical standards and have obtained certificates of good manufacturing practice are allowed to provide mixed feeds to ranches. The Animal Feed Commodity Committee is responsible for issuing good manufacturing practice certificates, and animal feed quality service agencies and national livestock meat testing service agencies are responsible for product inspection and supervision of the implementation of quality regulations. The quality assurance of the feed manufacturing process is achieved by implementing the following standards: quality management standards, feed ingredient detection standards to monitor harmful components), technical standards for feed manufacturing equipment, hygiene standards for manufacturing and storage, and final inspection standards for feed products (composition and quality ), Transportation and storage standards for final products and materials. ^[4]