CaHPO(4)center dot 2H(2)O (I) was pptd. from aq. solns. of H(3)PO(4), CaO and CaCO(3), studied for grain size distribution, content of P and soly. in H(2)O, aq. HCl, aq. citric acid and NH(4) citrate-solns., and then used as fodder additive in growing rams to evaluate its bioavailability. The highest soly. of I was Iobsd. in neutral NH(4) citrate sal. The use of I phosphate in ram farming resulted in an improvement of the P digestibility and retention.