Journal of Veterinary Diagnostic Investigation 2005-05-01

Acute depigmentation of fertile brown eggs in a commercial layer operation.

Bruce R Charlton, Asheesh K Tiwary, Arthur A Bickford, Mike Filigenzi

Index: J. Vet. Diagn. Invest. 17(3) , 286-8, (2005)

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Abstract

Rapid depigmentation of brown eggs is an infrequent but startling event in the commercial egg industry that can result in significant economic losses. Loss of shell pigment in brown-shelled eggs is caused by various factors. In many cases, the exact cause of flock-wide pigment loss remains undetermined. A rapid decline in shell pigmentation was observed in 2 flocks of Hyline brown layers. The lack of evidence of an infectious disease process suggested a feed or management problem. On the basis of a small-scale, "in-house" feeding trial, the feed was identified as the cause of depigmentation. Feed analysis by liquid chromatography with mass spectrometry confirmed the presence of 4,4'-dinitrocarbanilide, a major component of nicarbazin (NCZ). There was no evidence of increased mortality, and only a slight but transient drop in the egg production was observed. Depigmentation effects were rapidly reversed after replacing the feed with NCZ-free feed.