Egg Changes Associated with Reduced Interior Quality Because of Dietary Vanadium Toxicity in the Hen

Ammonium metavanadate was added to a control low vanadium corn-soybean meal laying ration (2 mg/kg) to supply 20 and 30 mg/kg added vanadium. Single Comb White Leghorn hens at 33 weeks of age were given the control feed for 4 weeks, then three groups having equivalent performance were formed. Dietary treatments were imposed for a subsequent 4 weeks. Treatment comparisons were made on the differences arising between the standardization and experimental periods. Adding vanadium had no effect on egg production and feed intake; however, birds receiving 30 mg/kg did not gain as much weight as those receiving other treatments. Eggs were examined on the day following collection for the last 4 days of each period. Egg weight was unaffected by vanadium, but Haugh units were reduced. Total albumen decreased with interior quality while the proportion of outer thin increased at the expense of inner thin albumen. Protein concentration and electrophoretic pattern of each albumen were unaltered. Removal of the oviduct at termination of the experiment revealed that magnum weight was reduced at the highest level of vanadium. Deterioration of internal quality by vanadium is speculated to be mediated by an inhibition of magnum motility during egg formation. Based on all albumen measurements, functional properties that could affect consumer use are not anticipated.