Diagnosis and Treatment of Common Poisonings in Chickens: Feed, Drugs and Environment (Part 1)

1. Cottonseed cake poisoning

Cottonseed cake contains 36%-42% crude protein and is rich in selenium, phosphorus and B vitamins, making it an economical and effective protein feed. However, cottonseed cake contains toxic substances such as free gossypol and cyclopropene fatty acids. After absorption, free gossypol can accumulate in the body and poison the cells of nerves, blood vessels and organs. Feeding cottonseed cake continuously over a long period will cause poisoning.

1.1 Symptoms. At the beginning of the disease, the flock's appetite decreases, water intake increases, the chickens are listless, the feathers are loose, the conjunctiva is blue-purple, the comb is slightly swollen and dark purple, the legs are weak, and the muscles tremble. In acute poisoning, bleeding occurs from natural openings such as the mouth, nose and anus, and blood-tinged loose droppings are passed. In laying hens, egg production drops sharply, eggshells are rough, and the number of soft-shelled and deformed eggs increases; the body gradually becomes emaciated. In breeding roosters, the testes atrophy, semen quality is poor, and the fertility and hatchability of breeding eggs decrease.

1.2 Necropsy. There is catarrhal or hemorrhagic inflammation in the gastrointestinal tract, the liver is enlarged, the lungs are edematous, the myocardium is flabby, the abdominal cavity contains pale red exudate, and the ceca contain a large amount of pale yellow contents.

1.3 Prevention and treatment. There is no specific treatment for this disease. After the disease occurs, immediately stop feeding the compound feed containing gossypol. For sick chickens, mix ferrous sulfate evenly into the feed at a ratio of 0.5% and feed it for 3 consecutive days, then halve the dose and continue for another 7 days. At the same time, vitamin E can be used, adding 10-20 g per kg of feed, mixed evenly, for 15 consecutive days, which can help promote the recovery of the hens' egg-laying function.

Rational use of cottonseed cake can prevent cottonseed cake poisoning. The methods are: (1) Detoxification treatment. Detoxification treatment can improve the utilization rate of cottonseed cake. A common detoxification method is to add an iron agent, adding 1 kg of ferrous sulfate per 100 kg of cottonseed cake. In addition, stir-frying the cottonseed cake in a pan for 1-2 hours can also effectively detoxify it. (2) Limit the feeding amount and feed intermittently. Cottonseed cake should not exceed 2%-3% in the diet of chicks, and should not exceed 5%-7% for laying hens. After detoxification treatment, it can account for 15%-20% in the diet of broilers; otherwise, it should not exceed 10%. To prevent gossypol from accumulating in the body, feeding should be stopped for 2-3 weeks after 1-2 months of continuous feeding, so that residual toxins in the body can be excreted. (3) Supplement green feed or add multivitamins. Green feed can significantly enhance the body's ability to detoxify free gossypol and can prevent secondary vitamin A deficiency.

2. Rapeseed cake poisoning

Rapeseed cake is a relatively good protein feed, with a protein content of about 30%, and its amino acid composition is better than that of cottonseed cake. However, rapeseed cake contains glucosinolates, which under the action of myrosinase produce toxic isothiocyanates and oxazolidinethione.

2.1 Symptoms. After poisoning, chickens show difficulty breathing, foam-like material flowing from the nose, diarrhea, and blood in the droppings. In severe cases, the pupils dilate, the legs are weak, and death eventually occurs from exhaustion.

2.2 Necropsy. The thyroid gland is enlarged, the gastrointestinal mucosa is congested, hemorrhagic and sloughed, the liver has more fat deposition and hemorrhage, and the kidneys are enlarged.

2.3 Prevention and treatment. There is currently no specific therapeutic drug, and the chickens can gradually recover after feeding is stopped. Rational use of rapeseed cake can effectively prevent poisoning.

(1) Detoxify before use. Methods include pit burial, water soaking, heating, ammonia or alkali treatment, and the "6017" tea seed cake detoxifying agent, etc.

(2) Limit the feeding amount. For laying hens, do not exceed 5%; for growing chickens, do not exceed 7%-10%. When using it, the amount should be increased gradually.

(3) Combined use. Mixing rapeseed cake with other cakes or animal protein feed for feeding can not only meet the chickens' comprehensive protein needs, but also reduce the proportion of various cakes and meals in the diet and avoid poisoning.