Etiological analysis of chicken gout

Gout is caused by uric acid metabolism in chickens. The concentration of uric acid in the blood is increased. A large amount of uric acid is excreted by the kidneys. Kidney damage and renal dysfunction caused by various causes further impair the excretion of uric acid and form a metabolic disease of uric acidosis. Mostly occur in broilers and cage chickens. The main causes of chicken gout are the following:

1, lack of VA

VA has a protective effect on the mucous membranes. In the absence of VA, it can cause keratinization and squamous metaplasia of renal tubules, collecting ducts, and ureters. Due to the keratinization and metaplasia of the epithelium, the secretion of mucus is reduced, and the discharge of urate is blocked to form an embolus, urate, which blocks the lumen and gout occurs. When the unreasonable combination of trace elements and vitamins and the storage time of the feed material is too long, it will cause a lot of destruction of vitamin A, due to the lack of vitamin A cause renal epithelial damage, glomerular filtration rate was significantly reduced, uric acid and phosphorus excretion blocked When yeast protein is used instead of fishmeal, since the main component of yeast protein is nuclear protein, the final product after metabolism in the liver of poultry is mainly uric acid, so that the concentration of uric acid in blood is too high, uric acid is deposited on the surface of internal organs and kidney, and finally Kidney units are heavily destroyed and kidneys are failing. Therefore, vitamin A must be supplemented in this diet.

2. Feed too much protein-containing feed

Beans, animal organs, fish meal, and meat and bone meal are high in protein. Since poultry livers do not contain arginase and cannot synthesize ammonia into urea, and kidneys cannot carry ammonia because they have no glutamine synthetase, poultry protein metabolites are produced through purine nucleotide synthesis and decomposition pathways to produce uric acid. Excreted form. The kidney is the most important and critical organ of uric acid metabolism in poultry and is the only excretion channel for poultry uric acid. When the function of poultry kidneys is normal, uric acid can be rapidly excreted through the kidneys, so that the blood can maintain a certain level of uric acid (1.5 - 3.0 mg) and will not cause diseases. However, when the dysfunction of the kidney or the product of uric acid is too high, the concentration of uric acid in the blood increases, and the formation of urate combined with Na+ and Ca2+ in the blood is extensively deposited in the body, and ureteral blockade will inevitably lead to uric acidemia. . As a result, the liver and kidneys are swollen and fragile. The renal tubules and ureters expand due to obstruction of urate crystals, and white lime-like dilute feces are excreted. The joint surface occurs due to frictional stimulation of urate precipitates in the joint cavity. Erosion and exudation lead to swollen joints, movement disorders or paralysis. Some chicken farmers are pursuing excessively high growth rates and egg production rates. Excessive protein feeds (such as bean cakes, animal organs, fish meal, etc.) are added to the feed. The uric acid produced by the decomposition of nucleic acids exceeds the discharge capacity of the body and a large amount of urate is It is deposited in the gut or joints and causes gout.

3, feeding high calcium feed

Some feed manufacturers only seek profits, do not seek quality, excessive addition of stone powder and shell powder in the finished feed, resulting in high calcium and low phosphorus, resulting in a serious imbalance in the proportion of calcium and phosphorus. In addition, some chicken farmers use laying hens to feed their chicks. Some chicken farmers use broiler feeds to increase the growth of broiler chickens, or excessively add shell powder and stone powder to the broilers. Secondary hypercalcemia, hypercalcemia lead to increased secretion of parathyroid hormone, increased intracellular calcium concentration in renal tubular epithelial cells, under certain conditions, calcium deposition and gradual calcification in the kidney, when calcified renal tubular epithelial cells fall off To the lumen of the renal tubules, it becomes the basis for the formation of kidney stones, cells continue to fall off and gradually aggregate, forming kidney stones; at the same time, due to the continuous destruction of nephrons, the nephrons of organic energy activities gradually decrease, which is insufficient to compensate All kidney function, resulting in compensatory enlargement of the kidney and chronic renal insufficiency. When Ca2+ in the feed is too high, a large amount of calcium salt will precipitate from the blood and deposit in the internal organs or joints, forming calcium-salt gout.

4. Unreasonable use of certain antibiotics

Many drugs have damaging effects on the kidneys, such as sulfonamides, aminoglycoside antibiotics, and cold-flux, which are excreted in the body through the kidneys and have potential toxic effects on the kidneys. If the drug is used for too long, if it is too large, it will cause kidney damage. In particular, sulfa drugs have high solubility under alkaline conditions and easily crystallize under acidic conditions. If long-term high-dose application of sulfa drugs but not with the use of basic drugs such as NaHCO3, sulfa drugs will be crystallized, and deposited in the kidneys and ureters, affecting the function of the kidneys and ureters, causing excretion disorders, and make uric acid Salt deposits form gout in the body. In particular, some chicken farmers in the incidence of chickens, all the antibiotics used in turn, and the dose is too large, especially the long-term use of large doses of sulfa drugs, it is easy to cause chicken gout. As long as the long-term use of oxytetracycline, chloramphenicol as long as the normal amount will not cause damage to the kidney; tetracycline, although there is a certain role in nephrotoxicity, but no adverse effects on normal kidney function.

5. Insufficient drinking water

Insufficient drinking water is a cause of gout in poultry. In hot summer or long-distance transportation, if the drinking water is insufficient, it will cause dehydration of the body, promote urine concentration, the body's metabolites can not be excreted in time, resulting in deposition of urate in the ureter, renal ureter is blocked by urate crystals, Induced gout.

6, feeding poor quality feed

Feeding poor quality fish meal. When the feed price soared and the benefit of chickens drastically declined, some chicken farmers faced difficulties in capital turnover and used cheap fishmeal. These fishmeal protein contents were low, and the salt content was high, often involving urea; some fish meal even became moldy. High levels of salt, urea, mold, and their toxins are negligible factors that cause kidney damage.

Feeding inferior bone meal is another important factor in the occurrence of gout. There are many manufacturers processing bone meal around the country. The source of bones is insufficient, and the quality is difficult to guarantee. Some bone powders are crushed without degreasing, degumming, and drying. The fat, gum, and moisture contained in it make bone meal extremely rancid and mildewed. Some even incorporate a large amount of shell powder in the bone meal, resulting in high calcium and low phosphorus, causing gout after feeding the chicken.

7, disease factors

The diseases related to chicken gout include kidney-type infectious bronchitis (IB), infectious bursal disease (IBD), and salmonellosis. Infectious bronchitis is a highly contagious disease in chickens and usually attacks the respiratory tract, but certain strains such as Holte, Gray, Italian, and Australian T have a strong nephropathic effect, resulting in nephritis and renal failure. Young chickens are most sensitive to kidney damage caused by infectious bronchitis, and initial infections may occur long before kidney function declines and dies. When the replacement hen is sexually mature, it is fed a diet with high calcium content for the purpose of laying eggs. If the kidney is damaged during the brooding or breeding period, the damaged kidney cannot be discharged as high as normal. The calcium, which leads to gout. In addition, avian nephritic virus (ANV) is an enterovirus that proliferates in kidney cells and can cause inflammation of the kidneys, leading to renal failure, and subsequent gout.