Prevention and treatment of white muscle disease in farmed ostrich

White myopathy, also known as myositis or muscular dystrophy, is a muscular degenerative disease, which is essentially one of the syndromes of a wide range of nutritional and metabolic lesions (including muscular dystrophy, liver dystrophy and adipose tissue inflammation, etc.). The disease occurs in poultry, poultry and domesticated special birds can occur, and has a certain geographical distribution. In addition, there are also diseases in mammals, such as horses, cattle, sheep and deer. The disease of young birds and breeding birds is more common, and young ostriches are more likely to occur. The etiology of leukomyopathy is not completely clear, but it is certain that the occurrence of this disease is closely related to the deficiency or deficiency of vitamin E and selenium and their mechanism of action. Selenium deficiency: there are obvious differences in selenium content in soils and plants all over the world. Mountains, hills and deserts mostly belong to low-selenium areas; alkaline soil has high water-soluble selenium and is easy to be absorbed by plants, while acidic soil has more compound selenium, but it is difficult to be absorbed by plants. Selenium has a strong antioxidant effect in animals, which can protect cells from the damage of oxides; selenium is a component of glutathione peroxidase, which can promote enzyme activation and play the role of decomposing peroxides. If selenium deficiency, it can lead to cell degeneration, necrosis and vitamin E destruction and the accumulation of unsaturated fatty acids, and finally cause inflammatory changes, degeneration and necrosis of liver, muscle and adipose tissue. It is generally believed that the appropriate selenium content in feed is 1 × 00.0000001, such as less than 5 × 0.00000001, it can cause different degrees of disease. In addition, there are too many antagonistic elements such as copper, zinc, arsenic, mercury and cadmium in feed, which can also affect the absorption of selenium and promote the disease. Vitamin E deficiency: vitamin E is also an antioxidant, which protects the cell membrane from the damage of peroxides, and its mechanism is to inhibit the production of peroxides. Vitamin E deficiency can be caused by feed rancidity, unreasonable diet ratio, improper harvesting, processing and storage of feed and forage grass (exposure, baking, mildew, water immersion and poor ventilation, etc.).

[main points of diagnosis]

The main results are as follows: 1) epidemic characteristics this disease has obvious epidemiological characteristics. One is that it is regional and mostly occurs in low-selenium areas, such as an oblique selenium-deficient belt from Heilongjiang to Yunnan in China. There are about 2x3 selenium deficiency in the whole country. Heilongjiang, Jilin, Inner Mongolia, Qinghai, Shaanxi, Sichuan and Xizang are selenium-deficient areas, especially in the north in the long winter and lack of green feed, which is very easy to occur the disease; second, it has certain seasonality. The disease mostly occurs in winter and spring (from October to April), during which the climate is cold and there is a serious lack of green feed rich in vitamins, coupled with the peak season of breeding and hatching of birds, which leads to the incidence of grinning young birds. Third, the disease occurs in groups, but it is not contagious. Fourth, all birds occur, and turkeys, ostriches and chicks are more common.

2) Clinical features the disease is characterized by inflammatory degeneration and necrosis of skeletal muscle and myocardium, hepatitis and adipose tissue inflammation (fatty liver, yellow liposis), resulting in weakness, dyskinesia, yellow staining and digestive system dysfunction. In the end, most of them died of exhaustion. Cases of young ostriches showed general weakness, drooping head, oblique neck, anemia, leg and chest muscle atrophy, unstable standing or even lying on the ground, some gait restrained, dishevelled feathers, depressed spirit. Most of them have diarrhea or watery stool. Breeding birds occur occasionally, but adult birds rarely occur.

3) the patients with exudative quality showed subcutaneous edema of chest and abdomen, edema at the root of leg and wing, and yellowish green colloid exudate or yellowish green fibrin in the edema. There are blood stasis spots on the neck, abdomen and inside of the waist. The main pathological changes of muscular dystrophy were skeletal muscle, myocardium, liver and pancreas, followed by kidney and brain. The muscle degeneration, light color, like boiled meat, muscle fiber loose, showing yellow-white, gray-yellow spot, strip or sheet, crisp, soft or necrotic, calcification. The myocardium dilated and thinned, there were bleeding spots in the endocardium of the papillary muscle, and gray-white or grayish-yellow spots parallel to the muscle fibers could be seen in the endocardium and subepicardium. The liver is enlarged with a crisp betel nut pattern. The kidney is congested and swollen with bleeding spots. Pancreatic degeneration. Some have enteritis.

[prevention and control measures]

1) the treatment can be treated by subcutaneous or intramuscular injection of 0.005% sodium selenite solution, 0.1-0.3 ml for chicks, 1 ml for adult birds, and 0.1-0.4 mg of α-tocopherol at the same time.

2) Prevention can add 1 × 0.0000001-2 × 0.0000001 sodium selenite to the diet of chicks and 20 mg of vitamin E per kg of feed. It should be noted that selenium is toxic, such as excessive use or long-term continuous use is easy to cause cumulative poisoning, such as miscalculation or uneven mixing is also prone to poisoning, generally replenished once every 15-30 days. The effective nutritional dose of selenium is 0.03-0.04mg / kg body weight, which can play the role of weight gain and disease prevention, the toxic dose is 3-4mg / kg body weight, and the dietary requirement is 1 × 0.0000001.