1 avian influenza virus is characterized by
flu virus influenza A virus, influenza B virus and influenza C virus three, including avian influenza virus belongs to the influenza virus, infectious large , Various forms. Avian influenza viruses and human influenza viruses have great specific differences in their receptors. Under normal circumstances, they will not infect humans. However, under certain special conditions, avian influenza viruses may mutate and may infect humans and harm The sex is greater. The avian influenza virus can be killed by disinfectants and is preventable, so disinfection prevention work must be done. In addition, the avian influenza virus can survive in a low temperature and humid environment, and can spread widely in an environment of 0 to 30 ℃. It has an adaptable low temperature and is the strongest in the winter and spring communication period each year.
2 popular features of avian
bird flu disease and climate, environment and flocks of immunity are closely linked. Under normal circumstances, the disease occurs more frequently in winter and spring, and rarely occurs in summer and autumn. If the relevant epidemic prevention work is in place, the probability of avian influenza in chickens will be greatly reduced; if the epidemic prevention is not carried out or not in place, the incidence of chickens will be very high, causing serious economic losses to the chicken farm, and even It will cause all the flocks to be infected.
In addition, the incidence of avian influenza has a great relationship with the breeding environment. In a chicken house with good environment and good air circulation, the incidence of chicken flocks is low; in a chicken house with a poor environment and too closed, the probability of chicken infection with avian influenza virus will increase. If a person feels breathing difficulties and smells in the chicken house, the air in the chicken house has been seriously polluted, which will cause great damage to the respiratory mucosa and air sacs of the chicken. Therefore, it is necessary to do a good job in the environmental sanitation of the chicken coop, clean and disinfect the ground regularly, and keep the air clean.
3 Clinical symptoms
After chickens are infected with avian influenza virus, corresponding symptoms will appear in different parts of the body. The specific manifestations are that the comb is black, and the edges are necrotic in severe cases; the heads of some chickens are swollen and the toes flow deep red blood. Some diseased chickens may also have circles, Nervous symptoms such as neck reflex. The feces of sick chickens became thin, yellow, green and a little white. Most of the eggs laid by sick hens had blood spots and thin eggshells, and the egg production dropped significantly.
4 control measures
4.1 immunization should be in place
for effective prevention of the occurrence of immunization is very important to prevent avian influenza, immunization work place is an important means to reduce the proliferation of large-scale bird flu epidemic. Under normal circumstances, chicken farms need to vaccinate the avian influenza H5N1 vaccine three times one and a half months before laying eggs, half a month before laying eggs and before laying eggs. For hens that have laid eggs, chicken farms should start from the beginning of October every year and receive avian influenza H5N1 vaccine and avian influenza H9N2 vaccine every two and a half months. It should be noted that these two vaccines should be vaccinated separately at an interval of no more than 10 days. In terms of immunization effect, the individual vaccination is better than the combined vaccination.
4.2 Environmental Management efforts to increase the sheds
to maintain good health coop has a great role in promoting the prevention of avian influenza occurred, and therefore must be prepared daily farm environmental management sheds, sheds ensure good ventilation. Due to the low temperature in the northern area and centralized heating in winter, some chicken farms will close the doors and windows of the chicken coop. Although this measure has a good thermal insulation effect, it will also greatly affect the air circulation in the chicken coop; in addition, chickens The high temperature in the house will cause chicken manure to ferment in a short time, which will decompose and produce more harmful gases such as ammonia and sulfur dioxide, which will seriously pollute the air in the house. At the same time, harmful gases will damage the respiratory mucosa and air bags of the chicken. . Once the respiratory mucosa and air sacs are damaged, the chicken’s immunity will decline, and harmful bacteria will take the opportunity to invade the chickens. This will greatly increase the probability of respiratory diseases, intestinal diseases, and influenza in the flock. Therefore, in winter and spring, the doors and windows of the chicken house should be opened from time to time to ventilate, and chicken manure should be cleaned in time to ensure the normal circulation of fresh air in the chicken house, thereby reducing the probability of bird flu in the flock.
4.3 Implement disinfection work
In addition to ensuring that the sanitation of the chicken house is in place, the chicken farm should also implement disinfection work. When the chicken house is regularly disinfected, smoking can be used. Disinfecting chicken coops with disinfectant smoke can not only remove viruses and bacteria in the air, but the reaction of the gas produced by the burning of Chinese herbal medicines with ammonia and sulfur dioxide in the air can also greatly reduce the damage of harmful gases to the respiratory system of chickens. At the same time reduce the incidence of bird flu. In addition, for chickens that have become ill, the chicken farm should isolate them, or adopt incineration and deep burying treatment, and should also thoroughly disinfect the chicken coop where the dead chickens are located.
In summary, in the breeding process, once the chicken farm bird flu, can easily cause serious harm, and therefore needs to be an important disease of avian influenza as a necessary epidemic prevention. In the production process, chicken farms need to do a good job in immune prevention and chicken house environment improvement, and also establish a scientific and systematic disinfection management system. For chicken flocks infected with avian influenza virus, chicken farms need to take targeted scientific and effective measures to do follow-up treatment according to the disease situation of the flock.
The characteristics and prevention measures of avian influenza in chicken farms
1 avian influenza virus is characterized by