Influence of phosphorus intake on excretion and blood plasma and saliva concentrations of phosphorus in dairy cows

Influence of phosphorus intake on excretion and blood plasma and saliva concentrations of phosphorus in dairy cows

Centraal Instituut voor Voedingsonderzoek TNO
Valk, H.
Šebek, L.B.J.
Beynen, A.C.

2002

Phosphorus (P) balance, and blood plasma P and saliva P concentrations were measured in multiparous dairy cows through two lactations and two dry periods. The cows were fed three amounts of P at either 100, 80 or 67% of the Dutch P recommendation, actually resulting in dietary P concentrations of 3.2 to 3.9, 2.6 to 2.9 and 2.2 to 2.6 g P/kg dry matter during lactation for the three treatments, respectively. On the basis of plasma P values as low as 0.9 mmol/l and saliva P values as low as 5.1 mmol/l during the second lactation period within the experiment, the 67% group was considered to be deficient in P. By decreasing milk production, and thus lowering P losses with milk, P retention in the 67% group remained near zero. The P supply with the 80% ration was considered to be just sufficient. At high milk yield and marginal dietary P concentrations, plasma P and saliva P concentrations were decreased. The higher P intake in high-compared with low-producing cows resulted in a constant absolute fecal P excretion, due to the fact that the apparent P digestibility was raised with increasing milk yield. There was a direct relationship between milk P output and the percentage of apparent P digestibility for individual animals. Chemicals/CAS: Phosphorus, 7723-14-0; Phosphorus, Dietary

Animals
Cattle
Digestion
Feces
Female
Phosphorus
Phosphorus, Dietary
Saliva

http://resolver.tudelft.nl/uuid:3a8d386b-5604-4479-bfc3-04545cee94c5

236712

0022-0302

Journal of Dairy Science, 85 (85), 2642-2649

article