ON THE PHOSPHORUS REQUIREMENTS OF CHICKENS FOR EGG PRODUCTION AND HATCHABILITY

Abstract

An experiment was made in an attempt to determine the availability of the phosphorus in soft phosphate as compared with that in dicalcium phosphate for laying hens fed a diet of natural ingredients. A high efficiency "all-vegetable" diet containing 0.38 per cent total phosphorus and an estimated 0.11 per cent nonphytin phosphorus was fed without added phosphorus and with sufficient dicalcium phosphate or soft phosphate to supply 0.05 and 0.1 per cent phosphorus. The calcium content of all diets was kept constant at 2.4 per cent.The results indicated that the inclusion of supplementary phosphorus did not improve egg production or feed required per dozen eggs. Differences were not demonstrated in body weight maintenance, egg weight, specific gravity of the eggs, hatchability, or bone ash at the end of a 44-week period of production.The results suggest the possibility that egg weight loss after 14 days’ incubation may have been influenced by supplementary phosphorus. Evidence for this effect was not clear-cut and more work appears desirable in this connection.It is concluded that it is not possible to assay feed phosphates for laying hens with diets of natural ingredients. It would also appear that a level of 0.38 per cent total phosphorus and 0.11 per cent nonphytin phosphorus is adequate for laying hens.Supplementation of an "all-vegetable" laying diet with Vigofac did not improve egg production, feed efficiency, egg weight, egg-shell quality or hatchability.