Urolithiasis or Calcium Excess in P ...

Urolithiasis or Calcium Excess in Pullet Diet or Calcium Excess in Laying Hens

Urolithiasis or Calcium Excess in Pullet Diet or Calcium Excess in Laying Hens

Urolithiasis is primarily seen in laying flocks and has been associated with increased mortality and decreased egg production. Urolithiasis is characterized by severe atrophy of one or both kidneys, distended ureters, and varying degrees of renal and visceral deposits. (1, 2, 3)

Overall mortality in affected flocks may exceed 2% for several months, and in excess of 50% of this mortality may be due to urolithiasis. (1, 2, 3)

Laying hens die suddenly and may be in good condition and full of lay or they may have a reduced muscle mass, small pale combs, and white pasting on pericloacal feathers. (1, 2, 3)

Feed pullets diets containing 3.0% of calcium (Ca) and 0.4 % of phosphorus (P)  from 8 to 20 weeks of age. (1, 2, 3)

Pullet feed on the 3.25% calcium (Ca) diet developed a high incidence of Urolithiasis by 18 weeks, which persisted or increased in laying period through 51 weeks of age. Low levels of dietary phosphorous during the rearing period exacerbated the effect of excess calcium. (1, 2, 3)

Fed pullets with excess dietary calcium, in particular, if combined with low available dietary phosphorous, may cause urolithiasis.

The occurrence is always more severe when immature pullets are fed high calcium diets for an extended period during maturity. In several outbreaks, potential problems in vaccination programs against infectious bronchitis have been identified. (1, 2, 3)

When urolithiasis is associated with Infectious Bronchitis virus infection in layer flocks, there may be an increase in mortality and egg drop, but otherwise, the flock appears healthy. (1, 2, 3)

The fact that some mycotoxins are nephrotoxic led to the suggestion that they should be considered as a potential cause of urolithiasis. In many outbreaks of urolithiasis, it has been difficult to isolate infectious bronchitis virus from affected laying birds. (1, 2, 3)

Excess dietary calcium in particular if combined with low available dietary phosphorous, feed to growing pullets has cause urolithiasis in an experimental trial. (1, 2, 3)

Water deprivation has been suggested as a cause of urolithiasis on the basis of field observation. The fact that some mycotoxins are nephrotoxic led to a suggestion that they should be considered as a potential cause of urolithiasis. (1, 2, 3)

Observed Clinical Signs Happenings

Egg drop

  • Egg production drops gradually

Visibly sick birds

  • Few visibly sick birds

Mortality

  • Low mortality or increases gradually
  • Laying hen die suddenly and may be in good condition and full of lay
  • Overall mortality in affected flocks may exceed 2% for several months, and in excess of 50% of this mortality may be due to urolithiasis

Dead birds

  • Good bodily condition
  • Poor bodily  condition

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

  • Small pale combs

Body Parts

  • Some birds may have a reduced muscle mass
  • weight depression

Droppings

  • White pasting on pericloacal feathers

Feathers

  • White pasting on pericloacal feathers

Diet

  • Excess dietary calcium in particular if combined with low available dietary phosphorous, feed to growing pullets has cause urolithiasis in an experimental trial

Calcium Excess in Pullet Diet or Calcium Excess in Laying Hens DOES NOT show or exhibit or manifest any of the following clinical signs happenings:

  • Egg production declines rapidly
  • High mortality or increases rapidly
  • Many visibly sick birds
  • Flock behaviour activity change
  • Droppings abnormalities
  • Respiratory abnormalities
  • Neurological Nervous
  • Lameness or unusual movements, incoordination, reluctance to move
  • Eyes abnormalities
  • Feed Consumption Changes
  • Shell quality
  • Internal Egg quality
Causing Agents
Pullet feed on the 3.25% calcium (Ca) diet and Low levels of dietary phosphorous during the rearing period exacerbated the effect of excess calcium.
Affected Systems/Organs
Urinatry System
Spread
N/A
Mainly Affects
Kidney and visceral urate deposition ("visceral gout")
Solution
Adequate levels of Calcium and phosphorous in the pullet diets
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

0

Impact on Liveability

1


Impact on Production

2

Overall Economic Impact

2



  1. Y.M. Saif.2008.Disease of Poultry. 12th Edition. page 1137, 1177
  2. David E. Swayne. 2013. Diseases of Poultry 13th Edition. page 1222, 1254
  3. Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition.page 531
  4. Paul McMullin. 2004. A Pocket Guide to Poultry Health and Disease. First Edition.
  5. Steven Leeson, John D. Summers. 2008. Commercial Poultry Nutrition. Third Edition.
  6. Donald D. Bell, Williams D. Weaver. 2009.  Commercial Chicken Meat and Egg Production. Fifth Edition.
  7. Gail Damerow 1994. The Chicken Health Handbook.

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