Phosphorus net absorption in dairy cows subjected to abomasal infusion of inorganic phosphorus – a pilot study. Issue 3 (8th March 2012)

• Record Type: Journal Article
• Authors: Mogodiniyai Kasmaei, K.; Holtenius, K.
• Is Part Of: Journal of animal physiology and animal nutrition. Volume 97:Issue 3(2013:Jun.)
• Page Start: 599
• Page End: 603
• Publication Date: 2012-03-08
• Subjects: phosphorus overfeeding -- rumen‐fistulated cows -- small intestine; Animal nutrition -- Periodicals; Feeds -- Periodicals; 636.085
• DOI: 10.1111/j.1439-0396.2012.01282.x
• Languages: English
• ISSNs: 0931-2439

Abstract

Summary: 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 3 × 3 Latin square design. Monosodium dihydrogen orthophosphate dihydrate (NaH2 PO4 *2H2 O) was continuously infused into the abomasum for 4 days. The solutions provided 0, 14.4 or 28.8 g 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.