At present, there is a large temperature difference between day and night, and it is still cold at night. Some chicken farmers only paid attention to the cold insulation of chicken coops and neglected the air circulation, either because the density is too high, or because the chicken manure is not cleaned regularly, causing air pollution in the house. Sulfur dioxide, ammonia concentration is too large, harmful gas to stimulate the trachea and airbags of chickens, easily induced chronic respiratory disease, E. coli disease, infectious rhinitis, etc.; some brooding house temperature is not good, when high, low, high temperature Or too low can induce the occurrence of infectious bronchitis; or due to inappropriate use of vaccines to cause atypical Newcastle disease; some due to improper management of heating stoves, resulting in carbon monoxide poisoning; improper feeding caused gout and so on. The above factors not only affect the growth and development of chickens, but also cause morbidity and increase mortality. The prevention and control of several major common diseases that currently pose serious hazards to chicks are as follows:
First, chickens slowly call for coli disease or Clostridium infection
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2. Changes in pathology. The mucous membranes of the nasal cavity and infraorbital sinus are edematous, congested, and bleeding. There is a lot of mucus or cheese-like material in the antrum. There is a transparent to cloudy mucus in the throat and trachea. The most obvious change was in the airbag. The wall thickness of the chest and abdomen was thicker and cloudy. The number of light airbags was different from that of yellow beads or yellow foam. The weight of airbags attached to the wall was yellow, such as fried egg-like cheese-like mass. Things. In severe cases, the infraorbital sinus mucosa is inflamed, and turbid mucus or cheese-like substances accumulate in the sinus cavity. If the inflammation spreads to the eyes, one or both sides of the eye may be swollen with yellow cheese-like substances in the eye. If a secondary E. coli infection is observed, the heart and liver are coated with a white translucent cellulose-like film that is easily peeled off. Diffuse hemorrhage of the bowel wall, loss of intestinal mucosa, thinning of the intestinal wall, or scattered hemorrhagic patches on the bowel wall, which resembles floral fabrics. There are undigested feed particles in the intestine. In severe cases of E. coli, the undeveloped fallopian tubes of young chicks have thick, yellow-white cheese-like substances of varying thickness.
3. Prevention. While doing a good job of keeping the chicken house warm, do a good job inside the house, pay attention to ventilation, reduce the content of harmful gases in the house. After the onset of illness, drugs such as spectinomycin, lincomycin, tilmicosin, and large intestine gold (components: amoxicillin) were used to control the condition. Prevent the use of ammonia net (imported high-tech environmental freshener) sprayed on the feces in the shed or aisle can absorb large amounts of ammonia, purify indoor air, effectively prevent the occurrence of chronic respiratory diseases.
Second, synovial fluid Mycoplasma
The disease mainly infects chickens and occurs mainly in chickens aged 4 to 16 weeks. Acute infections are occasionally found in adult chickens. Chronic infections that occur after the acute infection period last for a lifetime. The disease can be spread horizontally or vertically.
1. Clinical symptoms. The chicken has a pale crown, difficulty walking, and lameness. The gait is "character", or "stepping on a stilt", or a leg stretches forward and sits on the ground. Loss of appetite, physical weakness, rough feathers, slow growth. In some cases, swelling around the ankle joints and paw pads, swelling of the toe joints in severe cases, and swelling and thickening of the outer skin of the keel keel.
2. The necropsy lesions. A large blisters appear on the chest keel of the diseased chicken. In the early stage of the disease, there is a light yellow jelly-like mucus in the blisters. Afterwards, it gradually turns into a turbid, sticky cheese-like yellow-white exudate, which is present in the synovial bursa of the keel and near the ankle joint. Between sheath and muscle. Elderly people with the disease will also have the same lesions in many places such as hip joints, ankle joints, and wrist joints.
3. Prevention. Same as mycoplasma but harder to cure. Severely sick chickens have no therapeutic value and should be eliminated. Patients with mild conditions should use lignomycin (compounds of spectinomycin and lincomycin) as soon as possible.
Third, carbon monoxide poisoning
1. The cause of the disease. When spring brooders burn coal for heating (especially in new wet brooding houses and coal stoves, which can generate a large amount of gas), carbon monoxide cannot be discharged in time due to closed doors and windows, poor ventilation, or chimney blockage, and smoking. Chickens inhale a large amount of carbon monoxide gas (in the blood, carbon monoxide and hemoglobin combine to form carboxyhemoglobin, causing the blood to lose its oxygen carrying capacity) and cause poisoning.
2. Diagnosis points. When the poisoning is lighter, it manifests as depressed spirit, loose feathers, loss of appetite, and retarded growth. When severe poisoning occurs, it is manifested as dyspnea, restlessness, followed by drowsiness, lethargy, paralysis, and phlegm and convulsion before death. The claws and ends are dark purple. Blood red cherry, poor coagulation. The chest muscles are light pink.
3. Prevention. When the brooding house adopts coal fire for heating, the smoke exhausting measures should be smooth to ensure good indoor ventilation. When poisoning is found, doors and windows should be opened as quickly as possible, ventilation and ventilation should be carried out. Lighter poisoning can gradually return to normal after 2 to 3 hours.