(1) The Ca and P metabolism of two groups of young sheep, depleted of these
minerals, was investigated in a series of three balance studies.
(2) During the first 10 days on the bone meal supplemented ration, the
inorganic P of the blood rose sharply from approximately 2•0 to 5•0 mgm. per
100 c.c. of blood, a level which was more or less maintained to the end of the
(3) Under the conditions obtaining the method of bone meal supplementation
had no influence on the efficiency of utilization of Ca and P. The implication
of this for the problem of phosphate feeding under practical conditions is briefly
(4) Ca and P utilization dropped considerably in the course of the 80 days
on the enriched ration. Retention figures for Ca decreased from 22•5 to 12•7
per cent. and those for P from 53•1 to 32•2 per cent.
(5) Due to the fact that no observations are available on the extent of
replenishment during the period of bone meal feeding the final interpretations of
these results must await the outcome of further investigations.