Cows on diets deficientin P have not responded P supplementation during late pregnancy, although theymay respond in early lactation. Bone metabolism of range cows has been monitored.All cows received complete mineral mixtures during wet season; during dry season,the imposed treatments were: complete mineral mixtures (MMC) or mineral mixtureslacking dicalcium phosphate, supplemented (MMR) or not (MM) with concentrate.Cows supplemented with the concentrate tended to show less variation on bonemeasurements. Calcium concentrations on bone ash were always below 34% withoutany symptom of Ca deficiency. Phosphorus concentrations on bone ash were alsomarginal, even in cows that received additional P all year round, while plasmaP was always normal. Osteocalcin and bone alkaline phosphatase showed highervalues (P<0.05) during late pregancy, when deoxypyridinoline concentrationswere the lowest. Deoxypyridinoline increased at parturition and during earlylactation. Cows that received concentrate also presented lower deoxypyridinolinemean values. After three years, beef cows did not show signs of bone loss inany of the treatments.
