Two experiments have been carried out with albino rats in which the
availability of phosphorus in bonemeal , bonemeal supplemented with red
oxide of iron and boneash have been tested out. In the preliminary experiment
the P was supplied at a level of 0.23 per cent., the Ca/P ratio being 2:1.
From this experiment no significant differences between the ash percentages of the femurs of the rats and the phosphorus retentions could be shown.
Low phosphorus retentions indicated that the P was supplied in excess of the minimal requirements of the animals.
In the second experiment P was supplied at a level of 0.16 per cent.,
the Ca/P ratio being 1.87. The percentage P retentions were considerably
higher than in the preliminary experiment, the average percentage retentions
being 76.07, 73.36 and 71.52. Again no significant differences could be
shown by applying statistical analysis to the ash percentages of the femurs and the P retentions, which implies that under the conditions of the experiment the availability to white rats of the P in the three supplements, are similar.