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6 main causes of erosions in gizzard and proventriculus

6 main causes of erosions in gizzard and proventriculus

It is estimated that between 15 and 25% of the birds routinely necropsied in broiler, breeder or layer farms suffer from proventriculus or gizzard erosions.

The consequences of such erosions should not be underestimated, as proventriculus and gizzard are very important digestive organs. Lesions make digestion painful, so affected birds consume less feed and show depressed growth.

ANATOMY

Proventriculus is a glandular organ that secretes hydrochloric acid and enzymes. Between proventriculus and gizzard there is an isthmus called transitional area, where feed can accumulate and the environment is anaerobic. Gizzard consists of two pairs of opposing muscles covered by a protective yellow layer called cornea layer or koilin layer. Its main function is mechanical digestion.

CAUSES OF EROSIONS

  1. MYCOTOXINS
    Feed contaminated by T-2 toxin, diacetoxyscirpenol (DAS) or monoacetoxyscirpenol (MAS), all belonging to the group of trichothecenes, cause erosions in proventriculus and gizzard by irritating the tissues.Main signs of mycotoxicosis are:

    • From slight erosion to complete visual disappearance of proventriculus glands.
    • Dilated and enlarged proventriculus, with weak walls.
    • Caustic effects in gizzard, with dark lesions.

    The use of mycotoxin binders with high adsorption rates for trichothecenes can prevent the erosions. On the onset of the disease, withdraw contaminated feed as soon as possible and administer a suitable mycotoxin binder.

    main causes gizzard Mycotoxins picture 1

    Picture 1: Mycotoxicosis.

  2. BACTERIAL INFECTIONS
    The most important bacteria affecting proventriculus and gizzard are Clostridium species (Clostridium colinum, Clostridium perfringens, etc) that grow in the anaerobic spaces of the transitional area.Main signs are dark necrosis affecting the transitional area and the upper part of the gizzard, with possible bleeding.Prevention is carried out through improving the digestibility of feed and using bactericide plant extracts. For treatment, antibiotics might be necessary.
  3. FUNGAL INFECTIONS
    • 3.1 INFECTIONS BY ASPERGILLUS AND FUSARIUM
      Aspergillus and Fusarium species are able to grow in gizzard. The infection begins with a small brown protrusion in the cornea layer that leads to ulcers in a later stage. Cornea layer becomes very easy to detach and white fungal filaments can be observed under it.The origin of the infection is feed contaminated with molds (especially if higher than 2 million spores/gram of feed), moldy bedding or moldy environment. Fungicide plant extracts and organic acids can prevent the disease, together with biosafety programs. On the onset of the disease, plant extracts and organic acids can also ameliorate the lesions. The administration of copper sulfate is contraindicated as it can cause gizzard ulcers itself.

      main causes gizzard picture 2

      Picture 2: Aspergillus or Fusarium infection in gizzard.

    • 3.2 INFECTION BY CANDIDA ALBICANS
      Under certain conditions such as immunosuppression or antibiotic abuse, the yeast Candida albicans, an opportunistic pathogen, is able to colonize beak, crop and proventriculus. In proventriculus, white masses can be observed.Prevention can be carried out with products based on fungicide plant extracts and organic acids. The same products can contribute to ameliorate the disease. Nystatin or fluconazole are the pharmaceutical treatments of choice.

      main causes gizzard picture 3

      Picture 3: Candida growing on proventriculus.

    • 3.3 INFECTION BY MACRORHABDUS ORNITHOGASTER (MEGABACTERIA)
      Even if called “megabacteria”, Macrorhabdus ornithogaster is actually yeast. Originally it was thought to affect only ornamental birds, but has been demonstrated to infect broilers, laying hens, turkeys, quails and ostriches.Main signs are enlarged proventriculus, with irregular glands. Internal pH of the organ raises a lot, reaching pH=7-8. In the lab, smears stained by Giemsa reveal very large rod-shaped organisms.It is a little known condition that is easily confused with other diseases affecting proventriculus.
  4. VIRAL INFECTIONS
    There are many virus that could affect proventriculus and gizzard, among them Infectious bronchitis virus, avian pox virus, avian influenza virus, Newcastle disease, etc.The most important common sign for viral infections is bleeding. At necropsy, one can observe from small hemorrhagic focus to major bleeding, both on the proventriculus and on gizzard. Some viruses show characteristic signs, such as lymphomas in case of Marek infection.Identifying the exact viral agent and appropriate treatment requires an experienced veterinarian.
  5. NUTRITIONAL CAUSES
    • 5.1. Biogenic amines
      Amino acids that are naturally present in animal by-products used as feed raw materials become biogenic amines due to bacterial contamination. Biogenic amines stimulate acid secretion in proventriculus glands.Main lesions are ulcerations and fissures of gizzard, with bleeding, especially near transitional area and near the pylorus isthmus. pH inside gizzard is abnormally low.
    • 5.2. Black vomit
      The amino acids lysine and histidine present in fish meal become gizzerosine due to excess heating during processing. Gizzerosine stimulates acid secretion in proventriculus glands.Cornea layer is damaged; pH inside gizzard is abnormally low and gizzard turns black due to extensive bleeding.
    • 5.3. Other nutritional causes
      • Copper levels in feed > 250 ppm.
      • Sub-optimal levels of sulfur amino acids (methionine and cysteine) in diet.
      • Deficiency of vitamin E, vitamin B12, vitamin B6 or selenium .
  6. Controversial cases
    Sometimes dark erosions can be seen in the proventriculus of day one chicks. The origin of such erosions is under discussion. Possible causes:

    • Late access of the chicks to feed (starving).
    • Stress during incubation and/or hatching.
    • Mycotoxins in breeder feed.
    • Vertical infection by bacteria or virus.

CONCLUSIONS

Because of their impact on production parameters, diseases that affect the proventriculus and gizzard can not be ignored. Most of them could be prevented with the use of mycotoxin binders (PlusBind©), microbiocidal plant extracts (GrowthPlus© or PlusProtect Digestive©), biosafety programs and a good nutritional strategy.

For more information on this topic and on our products, do not hesitate to contact us through info@plusvet.eu

Certain health statements may not be applicable in your geographical region. Product claims may differ based upon your government requirements.

Copyright © 2014 PlusVet Animal Health

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Posted in: GrowthPlus Poultry, Mycotoxin binders, Mycotoxins, PlusProtect Digestive Poultry, Poultry, Products

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