Effect of dietary aluminum on calcium and phosphorus metabolism and performance of laying hens

The effect was studied of feeding dietary Al as aluminum sulfate on calcium and phosphorus metabolism and performance of Single Comb White Leghorn laying hens. In Trial 1, graded levels of Al (0, .05, .10, or .15%) were added to a corn-soybean meal layer diet containing 3.3% Ca and .5% available P. Each diet was fed for 28 days to six groups of six individually caged hens. Adding .15% Al to the diet significantly (P less than .05) reduced feed intake, egg production, body weight, tibia breaking strength, and plasma inorganic P. In Trial 2, graded levels of Al (0, .1, .2, or .3%) were added to the basal diet. Each diet was fed to five or six individually caged hens for 42 days. Feeding .3% Al significantly (P less than .05) decreased plasma inorganic P in samples collected immediately following oviposition after 10 and 42 days of treatment. Plasma total Ca, tibia weight, and tibia breaking strength were unaffected by dietary treatments. Egg production and feed intake during Days 1 through 21, but not during Days 22 through 42, were significantly reduced by .3% Al. The results indicated that the addition of .3% Al to a laying hen diet has a negative effect on P metabolism and egg production.