How to control respiratory diseases in broilers with low temperature in autumn and winter

Broiler rearing

The intensive feeding of broilers with high density has changed the feeding conditions and environment, and the management factor has become one of the decisive factors to control the survival of poultry, so that the farm is faced with many new problems with complex causes. for example, nutrition + environment + immune function deficiency + concurrent or secondary pathogens. High intensive feeding shortens the transmission process of viruses and bacteria, which makes the disease suddenly, spread rapidly, increase the opportunity of pathogen passage and recombination, and the frequency is fast, once the disease is difficult to control.

1. Intensive feeding is a friend of respiratory infectious diseases.

Continuous intensive feeding, so that there are a large number of known and unknown pathogens in the environment, and there are also a large number of conditional respiratory pathogens in the body. When the environmental conditions in vivo and in vitro change, these congenital factors determine infection is inevitable. The mixed infection of bacterial and viral respiratory diseases is becoming more and more common, especially the immune carrier of some acute acute respiratory viruses, which increases the difficulty of the treatment of bacterial respiratory diseases.

2. Cold is the key inducement of respiratory disease.

Cold stimulation causes peripheral vasoconstriction and reflex vasodilation and congestion in deep and visceral parts of the body. long-term passive stasis hyperemia creates favorable conditions for pathogen infection. Cold destroys the barrier mechanism of respiratory tract mucosa, stops the movement of ciliated epithelium, reduces the secretion of lysozyme, increases the decomposition of tissue protein, increases the number of macromolecular colloidal proteins in blood, weakens the activity of intrareticular system, and weakens the body's resistance. therefore, the most important thing to prevent respiratory diseases is to prevent cold stimulation and enhance the body's ability to resist cold stress.

3. Low humidity is the inducement of respiratory disease.

During the broiler breeding period, only pay attention to temperature, do not pay attention to humidity, the humidity in the environment is not enough, too much dust, resulting in dry respiratory mucosa, defense function decline, creating conditions for the reproduction of conditional pathogenic bacteria.

4. vaccination reaction leads to the occurrence of respiratory tract.

Because the vaccine is too virulent and has a strong stimulating effect on the respiratory tract, the vaccines used in actual production may be contaminated by mycoplasmosis resulting in seedling infection of mycoplasmosis and the stress of the vaccination process itself is an important cause of respiratory diseases.

Broiler rearing

Harm caused by respiratory dysfunction in poultry:

The respiratory system carries on the breathing movement under the nerve regulation, the body carries on the complex gas exchange between the external environment and the blood with this kind of movement. Once there is a problem in the respiratory system, the oxygen supply stops and the animal dies quickly. It results in the dysfunction of the immune system, the decrease of the protective function of respiratory mucosal barrier, the direct entry of pathogens into the body, the destruction of immune occurrence and recognition system, and the decrease of specific immune response.

How to control the multi-etiological respiratory tract of broilers:

1. The physiological characteristics of chickens determine that the frequent occurrence of respiratory diseases is closely related to the environment. Then environmental disinfection, especially air disinfection, is of great significance to the control of respiratory diseases, properly maintain the humidity in the house, reduce the content of dust, harmful gases and pathogenic microorganisms in the air, and reduce the intake of pathogenic microorganisms.

2. Change the feeding environment and implement full-in and all-out, cut off the transmission chain of preset factors in different batches of chickens, eliminate stress factors, and pay special attention to adopting one-stage feeding mode to avoid switching stress.

3. Put an end to the use of live vaccines with excessive virulence and avoid polluting the environment. The selective pressure of immunity leads to the continuous emergence of super virulent strains. The use of virulent vaccines will increase the virulence in the surrounding environment due to "selective immune pressure". The use of moderately virulent vaccines will be gradually stopped in conditional areas, the phenomenon of virus-carrying and detoxification of chickens will be reduced, and through biosafety measures, chicken farms with purified medium and high virulence will be gradually established.

4. Vaccination is the best way to control viral respiratory diseases.

The application of attenuated vaccine is a special need for the prevention and control of viral respiratory tract, the role of this local immunity, early, rapid, extensive direct action on the target organs (respiratory mucosal surface), can stimulate the lymphoid tissue of respiratory mucosa to mediate a variety of immune responses, including conditioning, agglutination, fixation, toxin and virus neutralization, blocking the adsorption, lysis and chemotaxis of cells.

Vaccination has the advantages of strong pertinence, high level of antibody production and long protection time, but it can not protect the pathogen of variant venereal disease. There is still a risk of infection during the immune blank period, and it is necessary to strengthen immunity to resist the infection of very virulent strains. Even if the immunization is very successful, it can only avoid the serious loss caused by highly pathogenic virus in broilers, but it is difficult to avoid the occurrence of virus-carrying virus and atypical diseases in broilers. For chickens with sound immune system, some severe infectious diseases can be avoided after reasonable immunization. for chickens with imperfect immune system, even after several times of immunization, it is inevitable that immune failure will occur at the age of susceptibility.