Cannibalism, Vent Pecking, Peckout, ...

Cannibalism, Vent Pecking, Peckout, Prolapsed Cloaca in Laying Hens

Cannibalism, Vent Pecking, Peckout, Prolapsed Cloaca in Laying Hens

Vent pecking generally occurs immediately after oviposition, and exposure of the mucous membrane stimulates pecking by others birds.

The first observable clinical sign is the increase in the number of  blood-stained eggs seen in flocks

It is more common when birds in floor systems lay their eggs on the floor in crowded areas

Vent pecking is responsible for at least 80% of all prolapses. It has been hypothesized that vent pecking may be the initiating lesion that triggers the onset of salpingitis in the oviduct and perhaps egg peritonitis

Cannibalism involves ingestion of part of other conspecifics, including skin, tissues and organs

Vent pecking occurs as egg laying begins, but other instances start at peak production or after and continuing throughout all the laying period

Feather pecking and cannibalism tend to reoccur and it is suggested that it may be a learned behaviour

This is a behaviour expressed by dominant birds at subordinates.

Vent pecking is more common when birds in floor systems lay their eggs on the floor in crowded areas or nest colony system. It occurs immediately after oviposition, and exposure of the mucous membrane stimulates pecking by other birds.

The appearance of blood on the exposed mucous membrane may lead to the death of the bird due to cannibalistic behaviour from the other birds in the flock or the bird has to be culled due to the severity of the injuries. Vent pecking occurs as egg laying begins, but other instances start 35 weeks old.

The number of blood-stained or smears on eggshells increased.  Some hens have bloodstained feathers around the vent due to the severe injury of the mucous membrane of the vent.

As the crude protein level of the diet is reduced, regardless of amino acid supply, there is also an increase in mortality (cannibalism) and reduced feather score. The feathering of white and especially brown eggs birds is adversely affected by low protein diets (lower score).

 

Observed Clinical Signs Happenings

Visibly sick birds

  • Few visibly sick birds
  • Wounds around the vent
  • The appearance of blood on an exposed mucous membrane of the vent
  • Birds with blood on their beaks will be seen

Flock behaviour

  • Increase flock mobility or activity
  • Vent pecking frequently occurs immediately after an egg has been laid when the cloaca often remains partly everted exposing the mucosa
  • Vent pecking occurs as egg laying begins, but other instances start at peak production or after and continuing throughout all the laying period
  • Feather pecking and cannibalism tend to reoccur and it is suggested that it may be a learned behaviour
  • Today, cannibalism is more common in the modern brown hybrids than the white layer lines
  • Up to 30% of the flock may be affected during an outbreak
  • The type of housing system markedly affects the prevalence of vent pecking with 22.5% of hens affected in free-range systems, 10.0% in barn systems, 6.2% in conventional cages and 1.6% in furnished cages, with a similar rank for the severity of vent pecking injuries

Mortality

  • Low mortality or increases gradually
  • Cumulative mortality  may be high
  • ·         Carcasses are found without viscera and with wounds around the vent (possible evisceration)

Dead birds

  • Good body fleshing condition or Well-fleshed

Body Parts (Neck wings breast abdomen shanks legs hocks feet joints vent skin)

  • Pecking damage to the cloaca the surrounding skin and underlying tissue
  • The appearance of blood on the exposed mucous membrane of the vent
  • Carcasses are found without viscera and with wounds around the vent (possible evisceration)
  • Bloodstained feathers around the vent

Egg quality

  • Blood stained or smears on eggshells
  • There are often a lot of bloodstained eggs seen in flocks

 

Feathers

  • Bloodstained feathers around the vent

Cannibalism, Vent Pecking, Peckout, Prolapsed Cloaca in Laying Hens  DOES NOT exhibit or manifest any of the following clinical signs happenings:

  • Egg drop
  • High mortality or increases rapidly
  • Dead bird in poor bodily  condition (“Skinny body”)
  • Many visibly sick birds
  • Flock behaviour activity: Decreased flock mobility or activity
  • Droppings abnormalities
  • Respiratory abnormalities
  • Neurological Nervous
  • Lameness or unusual movements, incoordination, ataxia
  • Eyes abnormalities
  • Head, Comb, Wattles, Face, Nostrils, Sinuses, Mount, Beak, Earlobes, abnormalities (except eyes)
  • Feed Consumption Changes
  • Internal Egg defects

 

 

 

Causing Agents
A complex multi-factorial behavioural problem. Predisposing factors include overcrowding, excessive light intensity or variation in environment (e.g. through shafts of light in the house or shed, high temperature, nutritional deficiencies, feed form, boredom, and strain of bird). Adequate husbandry. Rule out the factors such as: colony size, stocking density, nutrition and light regimen. In free-range and barn laying flocks, where pecking can be more of a problem, it is standard practice to use 0.18-0.20% sodium in the ration while for cage birds .014% is adequate. The higher level does not prevent pecking completely but it reduce the susceptibility of the flock to developing the vice, which is usually triggered by management factors.
Affected Systems/Organs
Integumentary system; Vent and Skin
Spread
None
Mainly Affects
Liveability
Solution
Adequate husbandry. Rule out the factors such as: colony size, stocking density, nutrition and light regimen
Suggested Actions
  • Can be confirmed with clinical signs and gross lesions
  • Can be dealt with in house
  • Technical assistance recommended
  • Can be managed with feed additives, off-the-shelf medications
  • Veterinary intervention is recommended

Impact on Egg quality

0

Impact on Liveability

2


Impact on Production

1

Overall Economic Impact

2



Y.M. Saif.2008.Disease of Poultry. 12th Edition. page 1149

David E. Swayne. 2013.  Diseases of Poultry 13th Edition. page 1233

Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition. page 97, 545

Steven Leeson, John D. Summers. 2008. Commercial Poultry Nutrition. Third Edition. page 173

 

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