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Research article - Peer-reviewed, 2013

Phosphorus net absorption in dairy cows subjected to abomasal infusion of inorganic phosphorus – a pilot study

Mogodiniyai Kasmaei, K; Holtenius, K


In this pilot study, the effects of phosphorus (P) supply on inorganic phosphorus (Pi) net absorption in dairy cows were investigated. Three non-lactating, non-pregnant, rumen-fistulated Swedish Red breed dairy cows were studied in a 3x3 Latin square design. Monosodium dihydrogen orthophosphate dihydrate (NaH2PO4*2H2O) was continuously infused into the abomasum for 4days. The solutions provided 0, 14.4 or 28.8g Pi/day. Rumen fluid volume and outflow rate were estimated at day four of each experimental period using cobalt-lithium EDTA as an external marker. Acid insoluble ash in feeds and faecal samples was used to quantify P faecal excretion. Concentrations of Pi in collected samples of rumen fluid, blood, faeces and urine were determined. Pi flow into the small intestine increased (p<0.05) with Pi infusion. Pi net absorption tended to increase (p=0.08) but proportion of absorbed Pi tended to decrease (p=0.08). Urinary Pi excretion was negligible and did not affect P homoeostasis (p=0.50). There was no change in plasma Pi concentration (p=0.45) in response to Pi infusion. The increase in total faecal P excretion (p<0.05) with increasing level of infused Pi was solely because of increased soluble faecal Pi (p<0.05). It is suggested that at P overfeeding, intestinal Pi net absorption is saturable in dairy cows.


phosphorus overfeeding; rumen-fistulated cows; small intestine

Published in

Journal of Animal Physiology and Animal Nutrition
2013, volume: 97, number: 3, pages: 599-603

Authors' information

Mogodiniyai Kasmaei, Kamyar
Swedish University of Agricultural Sciences, Department of Animal Nutrition and Management
Swedish University of Agricultural Sciences, Department of Animal Nutrition and Management

UKÄ Subject classification

Other Veterinary Science

Publication Identifiers


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