Poultry Liver: An Easy target for all Toxins… But a tough fighter too

The liver is the largest gland of the body and an accessory organ of the poultry digestive system. The liver involves in a wide range of functions including the fat mobilization and metabolism of carbohydrates, proteins, fats, vitamins and minerals, biotransformation, removal of waste products and detoxification. The liver is the main storage site of fat-soluble vitamins (A, D, K and E) as well as vitamin B12, glycogen, and some minerals like iron (Fe) and copper (Cu). Liver is also involved in the activation of vitamin D. The liver is the main site of phagocytosis; with the help of Kupffer cells, liver destroys aged blood cells and pathogens that may enter via the hepatic portal blood.

Normal healthy liver is dark brown in color and weighs around 4% of the bird’s total body weight.

This article is illustrating various pathological lesions of liver caused by mycotoxin, bacteria and virus and how metabolic disorders affects liver.

Mycotoxins are toxic metabolic byproducts of fungal growth on grains. High moisture content of grains can lead to fungal growth and toxin production. Fungi can produce toxins before or after grain harvest. Insect damage to the grain can increase the susceptibility of grain to fungal growth. Feeding on the grains containing fungal producing toxins cause moderate to severe liver damage. Due to this other signs like reduced egg production, fertility, and hatchability, depressed growth, feed conversion, and increased bruising and downgrading, and immunosuppression can also be seen.

Lesions associated with aflatoxin in liver include enlarged fatty livers with hemorrhage and anemia. Lesions associated with trichothecenes from Fusarium fungi include an inflamed, bright red to yellow hemorrhagic liver. Ochratoxin is the second most prevalent toxin produced by Aspergillus and Penicillum. Lesions associated with Ochratoxin include fatty liver with hemorrhage and urate deposits on the liver.

Candidiasis is an opportunistic fungal disease of the digestive tract of birds that is caused by the fungus Candida albicans. It commonly develops after use of therapeutic levels of various antimicrobials or due to contaminated drinkers/nipples facilities. Parasitic infestation and vitamin A deficiency may also make easy access of Candidiasis. Focal necrotic lesions in liver are seen due to Candidiasis.

These above conditions can be encountered in the farms compromising with good quality toxin binders. As feed never be infested by any single toxin but having multiple toxin at a time and liver affected by synergistic effect of these toxins. So, if a poultry feed is formulated without a toxin binder, the aflatoxin level under the acceptable limit (20 ppb) also can disturb the liver function.

Mycoplasma gallisepticum is commonly involved in the polymicrobial "chronic respiratory disease" in broiler chickens, leading to increased condemnations in the processing plant. However, its impact on liver cannot be ignored. Fibrinous perihepatitis is caused by Mycoplasma which is causing the most significant economic losses in poultry.

Scientific approach to treat the mycotoxicosis in poultry is to replace the contaminated feed immediately (don't go for dilution) and use of double dose of liver tonics and choline chloride in water for 7-14 days. This will revitalize the liver.

Deficiencies or disturbances of nutrition cause a variety of diseases. The diet may contain anti nutritional factors (ANF) which inhibits the absorption/utilisation, or metabolism of feed. Excessive lipid peroxidation caused by these ANF causes various degree of liver damage. Fatty Liver can be seen in the birds fed on high energy low protein ration while cage layer fatigue often results in liver parenchyma haematomas.

Liver affected in many bacterial infections. Enlarged bronze color mottled and brittle liver is a typical sign of Fowl typhoid which causes high mortality in poultry.

Tuberculosis is a chronic disease occasionally seen in small poultry flocks and rarely in commercial poultry. Liver lesions of Tuberculosis in poultry consist of white, firm masses of various sizes called as caseous necrosis.

Almost all viral disease determinate the liver health. Viral diseases which affect the liver the most are inclusion body hepatitis (IBH), Marek’s disease and Avian Leucosis.

Other conditions like visceral gout also affect the liver with noticeable findings such as presence of chalky white masses surrounding the liver and other organs. Liver can be evident with multifocal greyish white coalescing lesions in case of coccidiosis in poultry.

Whatever may be the etiology, poultry liver is first to affect and last to give up. Treatment approach should be started with following 3 steps:

1. Remove the source of causative agent (check feed, water, and litter)

2. Target specific treatment (Antibacterial, best quality toxin binder, etc.)

3. Supplementation of liver tonic (Liv.52 Protec) in double dose along with choline chloride in water for 7-14 days

Further, to avoid further damage to the liver, maintain the quality of feed and water, use toxin binder and liver tonic like Liv.52 Protec Powder on regular basis in the feed.