Vitamin D Severe Deficiency in Layi ...

Vitamin D Severe Deficiency in Laying Hens

Vitamin D Severe Deficiency in Laying Hens

Observed Clinical Signs Happenings

Egg Drop

  • Egg production declines rapidly
  • Several cycles of decreased egg production and shell strength may each be followed by periods of relatively normal production and shell strength

Visibly sick birds

  • Few visibly sick birds
  • Hens may show temporary loss of the use of the legs, with recovery after laying  an egg that is usually shell-less
  • During periods of extreme leg weakness, hens show a characteristic posture that had been described  as a “penguin-type squat”

Egg quality

  • Thin-shelled and soft-shelled or porous eggs
  • Shell-less Soft Shell
  • Egg specific gravity score lower (should be above 1.080 (1.068 thinnest shells)
  • Ungraded or second's eggs increased

Lameness or unusual movement incoordination ataxia

  • Temporary loss of the use of legs
  • Extreme leg weakness

Head Comb Wattles Face Nostrils Sinuses Mount Beak Earlobes

  • Beak, claws, become very soft and pliable

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

  • The sternum usually bend, and the ribs lose their normal rigidity
  • keel become very soft and pliable

Diet or Feed Changes (Recent Feed delivery, Recent formulation /diet, Other silo or improper storage, another feed brand)

  • Recent formulation /diet

Vitamin D Severe Deficiency in Laying Hens show, exhibit, or manifest any of the following clinical signs happenings:

Observed Clinical Signs Happenings

ALWAYS

NEVER

SOMETIMES

Egg drop

  •  

 

 

Egg production declines rapidly

  •  

 

 

Egg production drops gradually

 

  •  

 

Mortality above the standard

 

  •  

 

Visibly sick birds

  •  

 

 

Few visibly sick birds

  •  

 

 

Many visibly sick birds

 

  •  

 

Flock behaviour activity change

 

  •  

 

Droppings abnormalities

 

  •  

 

Respiratory abnormalities

 

  •  

 

Neurological Nervous

 

  •  

 

Lameness or unusual movements, incoordination, reluctance to move

  •  

 

 

Eyes abnormalities

 

  •  

 

Head: Comb Wattles Face Nostrils Sinuses Mount Beak Earlobes (except eyes)

  •  

 

 

Body Parts (Neck, wings, breast, abdomen, shanks, legs, hocks, feet, joints, vent, and skin, abnormalities), skinny body, retarded growth, weight depression

  •  

 

  • *

Feathers abnormalities

 

  •  

 

Feed Consumption Changes

 

  •  

 

Diet or Feed Changes (Recent Feed delivery, Recent formulation /diet, Other silo or improper storage, another feed brand)

  •  

 

 

Shell quality

  •  

 

  • *

Internal Egg quality

 

  •  

 

*  Sometimes has not been observed the Body parts abnormalities yet or depend on the course time of the disease

*Sometimes has not been observed the relationship between any feed or diet changes and the observed clinical happenings in a flock or several other flocks or different farms

*Sometimes has not been observed or measured the shell quality changes yet or inadequacy of monitoring systems, and even the course time of the disease

Causing Agents
Lack or Inadequate dietary amount of vitamin D particularly D3 Sulphur drugs in the feed may interfere with Vitamin D adsorption Vitamin D2 is sensitive to oxidation and catalyzed by minerals
Affected Systems/Organs
Reproductive and Locomotion System
Spread
N/A
Mainly Affects
Egg Production and Egg Quality
Solution
Adequate levels of vitamin D3. Calcium and Phosphorous ratio in the diet.
Suggested Actions
  • Can be confirmed with clinical signs and gross lesions
  • Technical assistance recommended
  • Can be managed with feed additives, off-the-shelf medications
  • Diagnosis should be confirmed with rapid assays and/or a certified laboratory
  • Veterinary intervention is recommended

Impact on Egg quality

3

Impact on Liveability

0


Impact on Production

3

Overall Economic Impact

3



  1. Y.M. Saif. 2008. Disease of Poultry. 12th Edition. page 1126
  2. David E. Swayne. 2013.  Diseases of Poultry 13th Edition. page 1211
  3. Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition.
  4. B.S, Bains. 1979 A Manual of Poultry Diseases. Editiones <Roche>, page 192

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