Studies on Calcium and Phosphorus Requirements of Laying Hens

Abstract

Calcium and Phosphorus requirements of laying hens seem to change due to their new feeding system, management and improvement of laying ability. Five sorts of diet with graded levels of calcium and phosphorus were given to five groups of hens to elucidate the calcium and phosphorus requirements in the conventional laying mash.The results are as follows.1. No influence of calcium and phosphorus level has been found on body weight, but low calcium and phosphorus diets decreased livability.2. Average feed consumption and feed conversion did not change due to calcium and phosphorus level. But when calcium level was the same, the addition of phosphorus in diet showed advantage.3. The egg production percentage was not different from NRC standard or calcium 3.4% and phosphorus 0.8% level, but in hot climate (July-October) the egg production percentage was lower on NRC level diet than on high calcium and phosphorus diet.4. Percentage of brocken and soft shelled eggs owing to calcium and phosphorus level was not revealed clearly.5. Calcium and phosphorus requiremts in conventional laying mash fitted to NRC feeding standard in this experiment but when calcium and phosphorus contents were higher than NRC standard in hot climate the egg production was improved. From this fact, in hot climate a litle higher than NRC standard level of calcium and phosphorus in laying mash seems desirable for layers.