Toxicity of vanadium in female Leghorn chickens

A study was conducted to determine the influence of dietary vanadium, fed after the onset of production, on hen day egg production, body weight changes, and mortality in laying breed chickens. Calcium orthovanadate was fed to 29-week-old female laying breed chickens at calculated levels of 0, 12.5, 25, 50, and 100 ppm dietary vanadium for five consecutive 28-day laying periods. Hen-day egg production and hen body weights were not influenced by the addition of 12.5 or 25 ppm dietary vanadium. Overall hen body weights and the hen day egg production were decreased in hens fed diets to which 50 ppm vanadium was added with a severe reduction in both parameters at 100 ppm. There were no mortalities during the experiment in the groups fed the 0, 12.5, 25, or 50 ppm vanadium diets. Mortality in the group fed the 100 ppm vanadium diet was 11, 39, and 56% at the end of the 28-day Periods 3, 4, and 5, respectively. There were no significant differences in egg weights, although a trend existed for lower egg weights with increasing levels of dietary vanadium.