title: Adverse effect of dietary vanadium, contributed by dicalcium phosphate, on albumen quality.
abstract: Two experiments were conducted to determine the effects of dietary vanadium (V) on egg albumen quality. In Experiment 1, White Leghorn hens fed 9.9 ppm V supplied from a commercial dicalcium phosphate (Dical B at 1.5% of the diet) or a diet containing 29.9 ppm V (28.5 ppm from ammonium vanadate and 1.4 ppm from Dical A) produced eggs with significantly poorer albumen quality (61.7 and 61.6 Haugh units, respectively) than those of hens fed 1.4 ppm V from Dical A (76.9 Haugh units). The decline in albumen quality occurred within 1 week of treatment and persisted through 4 weeks of V feeding. Inclusion of 28.5 ppm V as ammonium vanadate also reduced egg production and feed consumption but had no significant effect on egg weight or change in body weight during the 4-week test period. At the end of 4 weeks, all hens were fed the 1.4-ppm V diet. Improvement in albumen quality was observed within 1 week, and after 4 weeks of the recovery period, no significant differences among treatment groups were observed. Part 1 of Experiment 2 showed that albumen quality was significantly reduced by 6.0 and 7.9 ppm V, supplied from Dical B, but 2.0 or 4.0 ppm V did not significantly change albumen quality during a 4-week trial. In Part 2 of Experiment 2, the inclusion of 9.9 ppm V from Dical B again significantly reduced albumen quality within 1 week. The magnitudes of adverse effects of 6.0, 7.9, and 9.9 ppm V on albumen quality plateaued approximately 4 weeks after treatment began and remained relatively constant through 6 weeks of feeding 9.9 ppm V and through 10 weeks of feeding 6.0 or 7.9 ppm V. The results demonstrate that certain commercial dicalcium phosphates may contribute excessive V to the diet of hens, and, when present at levels of 6.0 ppm or more, V will adversely affect albumen quality.
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002130:Calcium Phosphates; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D004032:Diet; D004529:Egg White / Q000032:analysis; D005260:Female; D010047:Ovalbumin / Q000032:analysis / Q000378:metabolism*; D010058:Oviposition / Q000187:drug effects; D014639:Vanadium / Q000009:adverse effects*
chemical_list: D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D014639:Vanadium; C485838:calcium phosphate, monobasic, anhydrous; D010047:Ovalbumin; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous