Pathogenic characteristics and control measures of gastric erosion in chickens

Chicken myogastric erosion occurs in chickens, especially in broilers, which is similar to intestinal ulcer disease. whether the disease occurs or not is closely related to the application of fish meal in chicken feed. The occurrence of the disease often brings corresponding economic losses to the production.

I. Clinical symptoms and characteristics of the disease

All chickens at the age of 1 ~ 5 months can occur, and the mortality rate varies from 10% to more than 10%. The main manifestations of affected chickens were loss of appetite, mental malaise, crouching, fluffy feathers, emaciation, pale crown and beard, anemia, black-brown dilute vomit (so the disease is also known as "black vomiting disease"), diarrhea, black-brown soft feces or dark-brown thin feces. The affected chickens grew slowly and died suddenly, such as mixed infection or other diseases, the mortality rate increased.

II. Etiology and pathogenesis

The fish meal in the feed contains toxic substances that lead to muscle erosion, which is the root cause of the disease. In addition, the long-term lack of essential fatty acids in feed, which affects the absorption and utilization of fat-soluble vitamins, vitamin B6 and vitamin K deficiency, excessive use of copper sulfate and so on, are all related to the occurrence of the disease.

The production of fishmeal is mixed with poisonous fish such as mackerel, carp and mackerel; amino acids in fish protein form various amines under the action of bacteria During the processing of fish meal, high temperature makes it excessive free histidine and casein to form a casein mixture of histidine to form a casein mixture of histidine, which can increase the secretion of muscle and stomach. Excessive Lu substances lead to pathological changes of muscle and stomach, while the lamina propria of normal muscle and stomach has sand sac glands, which can secrete keratin that covers the surface of epithelial cells. It also acts as a barrier to prevent the damage of gastric contents to the mucosa, and the casein mixture of histidine can destroy this protective layer and disrupt the secretion of sand cystic glands, resulting in myogastric erosion and ulcers. Due to the loosening, brittleness and bleeding of the cutin-like protective layer, the outflow of blood turns black under the action of gastric acid and retrograde with the stomach contents to the crop, making vomit and descending diarrhea dark brown.

III. Changes of pathological examination

The body is characterized by systemic anemia. The main lesions are concentrated in the digestive tract, especially in the stomach and intestines. There are rice soup-like black-brown dilated liquid in the digestive tract; glandular stomach dilated and empty, mucous membrane exfoliated, erosion and ulcer in the middle and posterior regions; dark green or black cuticular membrane in muscle and stomach, thickening of wrinkle wall, sticky rough surface, severe erosion, little or no sand grains in muscle and stomach, dark green or dark brown remnant food; heart, liver, gland, lung, kidney pale, bile overflow Duodenal and cecal mucosal bleeding, surface necrosis, cloacal mucosal congestion. Laboratory microscopic examination showed that the structure of myogastric tissue was loose, the main cells and epithelial cells of the glandular duct under the horny layer were swollen, and there were exfoliated epithelial cells, cell fragments and focal lesions; the tissue of the subcuticular layer was liquefied and eroded, and the lamina propria dropsy, there were scattered focal neutrophil infiltration, significant thickening and relaxation of the cuticular membrane, and separated from the tissue below it. The duodenum has catarrhal, hemorrhagic inflammation, villi shedding, and focal lesions on the mucosal surface.

IV. Clinical diagnosis

Clinical diagnosis can be made according to the clinical symptoms, pathological changes (especially myogastric lesions) and the application of fish meal in formula feed, but attention should be paid to the differential diagnosis of coccidiosis in the process of diagnosis.

V. principles of prevention and control and prevention and control measures

1. Principle of prevention and control

Because the occurrence of the disease is closely related to the quality and dosage of fishmeal, the principle of prevention and control of the disease should be to change the amount of fishmeal in chicken diet. In the process of matching chicken feed, under the premise of ensuring the quality of fishmeal, other protein feed should be selected as far as possible to replace the amount of fishmeal. In addition, vitamin feeding should be supplemented to enhance the resistance of chickens; hemostatic agents should be used to reduce myogastric bleeding and prevent the symptoms of affected chickens from getting worse.

2. Treatment method

① was injected intramuscularly with vitamin Kl mg and Zhixue powder 80 mg per chicken, twice a day for 3 to 4 days to control gastric bleeding. ② was fed with vitamin B65 mg and vitamin C 40 mg per kilogram feed to enhance the resistance of chickens. ③ was fed to chickens with 4mg cimetidine per kilogram of body weight for about 7 days to control gastric acid secretion and protect gastric mucosa so as to promote myogastric erosion and ulcer healing.