Gizzard erosion (Photo: BIOMIN / Norbert Trattner)

Poultry

Gizzard Lesions

The muscular stomach or gizzard is located immediately after the proventriculus in poultry. Unlike the proventriculus, which produces a number of juices or enzymes that are used in the digestion or breaking down of food into its constituent nutrients, the gizzard serves a more mechanical purpose, aiding digestion by particle size reduction and regulation of feed flow.

The gizzard consists of a number of layers of tissues, some of which contain straight tubular glands. The innermost layer is a strong, flexible skin that is able to withstand the potentially damaging effects of the muscular action grinding the food, often in the presence of stones or other insoluble material. The glands of the gizzard produce a keratinised liquid material which hardens when in the surface to replace tissue worn away by the grinding action of the organ.

In spite of being a fairly strong organ, the occurrence of gizzard erosion or lesions in the mucosal lining (koilin) of the gizzard is often reported by field veterinarians in broiler and commercial layers operations. In some cases, these lesions are already observed in day-old chicks before placement in the broiler house and prior to feed consumption. For young chicks, studies point to post hatch stress or the presence of mycotoxins in breeder diets (which then carry-over into the egg) as possible factors. For older animals, a whole set of potential causes are worth consideration.

These tables provide checklists of the potential causes, description and corrective actions to take when birds present gizzard lesions or gizzard erosion.

Mycotoxins

Potential cause	Checklist	Corrective action
Type A-trichothecenes particularly T-2 toxin and DAS Mild to severe disruption of the koilin layer, which in severe cases causes lesions in the underlying tissues.	Standard post mortem examinations. Origin of raw materials from supplier/region with history of A-trichothecenes contamination. Check average contamination levels. Positive for A-trichothecenes in raw materials (ELISA) or feed (HPLC).	Prevent mold growth, purchase clean raw materials. Avoid contamination of feed bins or feed/water lines by stale, wet or moldy feed. Add an effective mycotoxin deactivator in the feed.

Potential cause

Checklist

Corrective action

Type A-trichothecenes particularly T-2 toxin and DAS

Mild to severe disruption of the koilin layer, which in severe cases causes lesions in the underlying tissues.

Standard post mortem examinations.
Origin of raw materials from supplier/region with history of A-trichothecenes contamination.
Check average contamination levels.
Positive for A-trichothecenes in raw materials (ELISA) or feed (HPLC).

Prevent mold growth, purchase clean raw materials.
Avoid contamination of feed bins or feed/water lines by stale, wet or moldy feed.
Add an effective mycotoxin deactivator in the feed.

Nutrition

Potential cause	Checklist	Corrective action
Biogenic amines Low quality/over processed fish meal can result in high levels of gizzerosine. Hyper-production of HCl in the proventriculus causes erosions in the gizzard.	Ensure only high quality fishmeal or animal by-products are incorporated into the diet.	Lower level of fishmeal in diet. Avoid use of low quality fishmeal. Replace standard fishmeal with low temperature (LT) fishmeal.
High levels of copper sulphate in diet CuSO₄ can promote gastric lesions especially at proventriculus and gizzard level.	Check formulation to ensure that levels of copper sulphate are at the correct level in premixes.	Apply group B vitamins and K₃ vitamin in water. Correct set up of the water dosing system.
Rancid fats Low quality fats (long storage, overheated) can have high levels of superoxide radicals and hydroxyl radicals.	Quality of fats in term of peroxide value, rancidity and free fatty acids.	Avoid low quality fats. Use low quality fats in the grower/finisher phases. Replace animal fats with vegetable fats
Acetylsalicylic acid and sodium salicylate Use of salicylates may induce proventriculus and gizzard ulceration.	Level of tannins in some raw materials (sorghum) and in tannin-based products.	Use high quality tannin-based product (chestnut better than quebracho). Reduce % of sorghum in diet when high in tannins.
Tannins Toxic levels of tannins in the feed cause esophageal and gastric edema, hemorrhagic ulceration, necrosis and sloughing of the mucosal lining.	Dosage of salicylates used (check overestimation of feed intake in feed restricted animals). Mixability of commercial product in water.	Avoid low quality products (low mix ability, low homogeneity in water). Correct feed intake assumption in feed restricted animals.

Pathogens

Potential cause	Checklist	Corrective action
Adeno virus contamination Adenovirus is the causal agent of inclusion body hepatitis (IBH) and other avian syndromes that affect the production. Vertically transmitted, usually sub-clinical but provides more exposure to secondary bacterial infection.	Check for high titre level in the blood (ELISA). The serum neutralisation test.	Biosecurity. Use inactivated vaccines (only available for group I). Check the breeding stock and eliminate the affected birds.
Newcastle disease Slight wounds, hemorrhage and necrosis of proventriculus - more often than generalized lesions.	SPF embryonated chicken eggs test and PCR.	Correct vaccination plan. Biosecurity
Infectious bursal disease (IBDV/ Gumboro) IBD is very immunosuppressive and causes lesions at the junction of the proventriculus-gizzard.	Atrophy of the bursa of Fabricius. Immunofluorescence or immunohistochemistry tests.	Biosecurity Implement/correct vaccination program in breeders. Change from mild to strong-reaction vaccine.
Candida albicans (Candidiasis) Thickening of the mucosa in the crop with white to off-white, raised circular or rugose lesions.	Observation of gross lesions. Diagnosis can be confirmed by demonstrating tissue invasion histologically and by culture of the organism.	Improve sanitation and minimize antibiotic use in poultry.

Others

Potential cause	Checklist	Corrective action
Prolonged periods without feed Hyper-production of HCl in the proventriculus causes erosions in the gizzard.	Check that feeder systems are working correctly	Reduction of the transport time.
Delay in pulling chicks resulting in a long period in the hatcher.	Check egg setting times and egg ages.	Adapt setting times to ensure a short hatch window.
High temperatures in the hatcher (specially between 17 - 20 days) Hyper-production of HCl.	Check the temperature during the incubation period.	Adjust the temperature and properly calibrate the incubation machines.

Potential cause

Checklist

Corrective action

Prolonged periods without feed

Hyper-production of HCl in the proventriculus causes erosions in the gizzard.

Check that feeder systems are working correctly

Reduction of the transport time.

Delay in pulling chicks resulting in a long period in the hatcher.

Check egg setting times and egg ages.

Adapt setting times to ensure a short hatch window.

High temperatures in the hatcher (specially between 17 - 20 days)

Hyper-production of HCl.

Check the temperature during the incubation period.

Adjust the temperature and properly calibrate the incubation machines.

What’s Wrong with My Birds?

Download What’s Wrong with My Birds?, a special issue of Science & Solutions

Find this handy checklist and more in our Science & Solutions special issue.

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A Nutritionist’s Perspective on the Removal of Antibiotics in Poultry Production

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Gizzard Lesions

Mycotoxins

Type A-trichothecenes particularly T-2 toxin and DAS

Nutrition

Biogenic amines

High levels of copper sulphate in diet

Rancid fats

Acetylsalicylic acid and sodium salicylate

Tannins