Phosphorus and the grazing ruminant. 3. Rib bone samples as an indicator of the P status of cattle

Author: M.V.P. Read, E.A.N. Engels & W.A. Smith
Year: 1986
Issue: 1
Volume: 16
Page: 13 - 17

Rib bone samples were taken from free-grazing, crossbred, beef-type cows at different stages of their reproductive cycles to monitor the P status of supplemented and unsupplemented groups. Two experimental sites, Glen and Armoedsvlakte were used, the latter notorious for its Pdeficient pastures. P content of bone samples (expressed as mg P/cm3 fresh bone) proved a reliable and sensitive indicator of the P status of grazing cattle. Concentrations suggesting adequacy (140 -150 mg P/cm3) agree with those pUblished elsewhere. During lactation, concentrations below 100 mg/cm3 were observed in the severely P-deficient (- P) group at Armoedsvlakte. There was no suggestion of even a sub-clinical deficiency at Glen; the only advantage of supplementation was maintenance of higher bone mineral reserves during late lactation, especially in the young heifer.



Keywords: bone biopsies, bone phosphorus concentration, grazing cattle, phosphorus, phosphorus status, phosphorus supplementation
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