How to prevent and control broiler mild bird flu

Broiler virus is raging, mixed feelings are common, and treatment is difficult. Breeders and clinical veterinarians are very confused. Among all the viral diseases, mild avian influenza accounts for the main theme and becomes the biggest killer, threatening the healthy development of the broiler industry.

First, the epidemic situation The disease occurs in chicken farms all year round, but mostly in the winter and spring, every year from November to April of the following year is a high incidence period. In horizontal transmission, diseased chickens pass through the digestive tract and respiratory tract to excrete viruses, which are transmitted through dust, feed, drinking water, and birds. Wind blows have a positive effect on the spread of this disease. Due to the rapid spread, infection can easily lead to an outbreak of chickens in the entire group, even affecting neighboring chickens.

Chickens of different ages, breeds and sexes can be infected. The incidence of medium or low virulent strains (such as H9N1, H9N3, H5N2) may reach 100%, but most are within 80%. If there is no secondary infection, the mortality rate is generally within 10%. Incorporating or secondary infection with bacteria can indirectly increase the virulence of the virus and thus increase mortality. The main reason leading to the onset of bird flu is the change in chicken house temperature. When the climate changes abruptly, cold currents strike, and when the chickens get cold, they develop respiratory diseases and the chickens easily get sick.

Second, the clinical symptoms and pathological changes chickens infected with bird flu, due to the virulence of the virus, species, age and health status, etc. showed very complex clinical symptoms. The diseased chickens showed respiratory tract symptoms such as coughing and throwing nose, and then they shed tears. Some chickens had upper and lower eyelids swollen, conjunctival hyperemia, red eyes, sticky or caseous secretions in the eyes, and swollen swollen faces; See later, dyspnea, breath sounds, and occasionally hear strange; rise in temperature of the affected chickens, visible purple crown tip, touch the increase in thermal sensation, purple bleeding spots in the hairless legs; chicken feed intake The initial growth was slow, then stopped growing, and then decreased and then decreased. It took about 10 days; feathers were fluffy, eyes were half-closed, and individuals were sluggish; early large-scale feces were almost normal, and fresh stools were seen in the late stages. Bad stools.

Moderate bird flu shows different necropsy changes due to geographical differences, seasons, species, and age. Mainly in the following four aspects: First, cause tracheal embolism. Nasal mucosal hyperemia, hemorrhage, infraorbital sinus mucosal spotting, tracheal ring hemorrhage, gray mucus inside, and sometimes cheese-like due to dehydration, bronchial and bronchiole yellow-white cheese-like blockage, chickens and more The suffocation went high and died. Lung congestion, edema, and darkening are more common. The turbidity of the airbag is turbid. In severe cases, the yellow cheese-like material of fried eggs is common. The second is causing kidney congestion. Broiler common kidney swelling, purple swollen or piebald-like enlargement, this phenomenon and kidney-type transmission, gout and other diseases have similarities. The differential diagnosis lies in the more serious dehydration of kidney-type transmission organs, the difficulty in peeling dry bodies, and the death of the legs under the abdomen. In addition, the kidney-type transmission does not have multiple bleeding sites corresponding to bird flu. Kidney flu, patchy kidney, and severe renal hemorrhage in bird flu have no obvious effect when using kidney-passing drugs. Third, there are cheese-like substances in the airbags, causing balloon inflammation. Clinically, more cheese-like substances appear in the airbags in the chest and abdomen. Fourth, lung lesions. A large area of ​​lung necrosis is a characteristic lesion of flu in broilers.

In addition, jelly-like edema can sometimes be seen subcutaneously in the head of the diseased chicken, and subcutaneous or subcutaneous fat in the neck often causes needle-like or spotting bleeding. This kind of spotted bleeding can be easily found when dissecting live birds, and the death time is long. You can't see it. Thymus swollen with small bleeding points; some strains may cause bursa edema, lobular hypertrophy; ileal lymph nodes often see edema, bright bleeding, cecal tonsils swelling and bleeding, bleeding is bright; and Newcastle disease in this lesion is obsolete Dark. The common spleen shrinks and sometimes darkens. The common sac is empty or filled with bright yellow fleas, and Newcastle disease is common in this sour mucus; glandular stomach swells, nipples bleeding, glandular gastric mucosal bleeding, muscle stomach keratoderm membrane strip hemorrhage, compared here with Newcastle disease Difficult to distinguish. The whole intestine showed diffuse hemorrhage; the pancreas was bleeding or liquid wax-like necrosis at the edge, sometimes swelling was chain-like, and Newcastle disease had no obvious performance here. Since 2009, the common liver has yellow or purple swelling, with yellow indentations on the surface. Inside and outside the heart of the strip of blood, or white strips of necrosis (like boiled), especially ducks, is very meaningful for the diagnosis of the disease, and Newcastle disease common coronary fat bleeding, myocardial symptoms do not show more.

III. Prevention measures 1 Prevention and control measures In all aspects of production, enhancing the resistance of broilers is the most important aspect of bird flu prevention and control. Keep the chicken house temperature relatively stable, and the temperature difference between white housewife in the house is generally no more than 3°C. This is the key to controlling bird flu and is more effective than any anti-flu medicine. Therefore, we must pay special attention to the weather forecast and correctly handle the conflict between ventilation and heat preservation. The standardized chicken house heater stove is the best equipment to solve the contradiction between heating and ventilation. Reduce stress and enhance chicken resistance. Vaccination is the most common stress factor and must be well-preserved before immunization. Minimize changes in the environment and pay attention to details in production management. Control the humidity in the house to avoid damage to the respiratory mucosa. To ensure that the humidity during the brooding period is not less than 65%, the medium-large chicken should not be less than 55%. Clean the trough and sink frequently, clean and replace moldy litter. Strengthen the blank period of chicken health care, in advance with traditional Chinese medicine (such as astragalus polysaccharides, etc.) to improve immunity, try to use good quality vitamins, cod liver oil. In the production practice, some technicians reported that sometimes chickens are not vaccinated with bird flu vaccine. However, once bird flu was immunized, chickens died in large areas. In fact, this is not a problem with the vaccine. Its root cause is that chickens themselves carry the bird flu virus. H9 is present in the trachea of ​​chickens, and the H9 virus itself is also undergoing different changes. The current H9 type does not have a good vaccine and the protection effect is not ideal. H9 can achieve a protection rate of 80% if it is of the type, and only 50% if it is not. However, it is better to have a vaccine than it is not. Therefore, it is necessary to strengthen vaccine immunization. Broilers can use single seedlings or they can use double and triple vaccines for immunization. The second is that when immunized by the vaccine, it is easy to spread by syringe needles, and it is easy to produce stress response when injected.

2 Treatment When there are eye deformations and tears in the chickens, the chickens should be subjected to a necropsy and the treatment measures should be taken immediately after diagnosis. Practice shows that the sooner the diagnosis is given, the sooner it is given, the better the treatment effect and the smaller the loss. Chinese medicine gypsum, honeysuckle, Scrophulariaceae, Astragalus, Rehmanniae, Forsythia, gardenia, gentian, Daqingye, sweet dicot, Banlangen, Anemarrhena, Ophiopogon japonicus, etc., with astragalus polysaccharides, generally have better results. Use sensitive antibacterial drugs to control secondary infections. The lighter-onset fluxinqing (pure Chinese medicine preparations. The main ingredients are Radix Isatidis, Astragalus membranaceus, Epimedium, Hypericin, Echinacea, etc.) are mixed (500 grams per bag, 1000 chickens over 30 days old/ Bag) + bottle of fluocin net (main components are florfenicol, doxycycline, potent erythromycin, etc. Each bottle of 100 g watered 200-300 kg) drinking water. Heavier disease with the use of a mixture of flu and poison + Huduqing (pure Chinese medicine preparations, Maxin Shigan powder. 500 g / bag, watered 300 kg) + amantadine + bottled fluorobacillus net drinking water.

Some clinical cases are like bird flu and kidney type transmission, and it is difficult to confirm the diagnosis. Under this circumstance, we can use Kang Kang (main components are Coptis, Astragalus, Cortex Phellodendron, Gardenia, the latest antiviral factor, interferon, etc., 100 grams of water per bag, 150 kg of water) + fluoxazole (the main ingredient is Banlangen, Glutinous crisp, bezoar, borneol, realgar, etc. Each bottle of 100 grams watered 300 kg) drinking water. You can also use Hudu Qing drinking water + kidney branch Hu Kang Ning (Chinese and Western combination formula, the main ingredient is Coptis, astragalus, cork, gardenia, broad-spectrum antibiotics, antiviral factors, cough and asthma combination, etc. 500 grams per bag, on the 30th Chickens of 800-1000 pieces/bag above age must not be fried or seasoned. Amantadine cannot be added. Or with a taste of a mixture of spices + Hudai Qing + amantadine + bottled fluorobacillus drinking water, at night with 0.4% baking soda through the kidney, the effect is very good.

In the early stage of influenza and air-saccharitis and peritonitis, the clinical manifestations were mostly airsacculitis and peritonitis. At this point can be used to taste a mixture of spices, call poison clear + amantadine + bottled fluoride bacteria net water.

For the case of influenza and air saccitis, peritonitis mixed late, secondary serious cases of E. coli, can use a sense of tasteless spices, call poison clear + amantadine + strut speed control (corporate secret formula, but there is no resistance and Incompatibility. 500 grams of water per bag 750-1125 kg) drinking water.