title: Influence of high phosphorus intake on salivary and plasma concentrations, and urinary phosphorus excretion in mature ponies.
abstract: This study addressed the question whether the concentration of phosphorus (P) in saliva of ponies is influenced by P intake. Six ponies were fed a diet high in P (HP treatment), providing 21 g P/day, and a diet low in P (LP treatment), supplying 7 g P/day. The two diets provided approximately 21 g calcium (Ca) and 6 g magnesium (Mg)/day. The experiment had an A-B-A design with treatment periods of 30 days. The ponies first received the HP diet (HP1), followed by the LP treatment and were then fed again the HP diet (HP2). Urinary P excretion was increased in both HP feeding periods and equalled approximately 7% of P intake vs. 0.5% on the LP diet. Plasma P concentration was higher for the HP treatment. The salivary P concentration ranged from 0 to 1.01 mmol P/l between ponies and there was no effect of P intake. It is suggested that saliva is not an important excretion route of P. The percentage of Ca and Mg in urine (% of intake) was higher for the LP treatment than for the HP treatments. The results of this study suggest that salivary Mg may contribute to Mg homeostasis.
authors.affiliation: Division of Nutrition, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. d.a.vandoorn1@uu.nl
authors.forename: D A
authors.initials: DA
authors.lastname: van Doorn
authors.forename: H
authors.initials: H
authors.lastname: Everts
authors.forename: H
authors.initials: H
authors.lastname: Wouterse
authors.forename: S
authors.initials: S
authors.lastname: Homan
authors.forename: A C
authors.initials: AC
authors.lastname: Beynen
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D006736:Horses / Q000097:blood* / Q000652:urine*; D008274:Magnesium / Q000378:metabolism; D008297:Male; D010758:Phosphorus / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D016226:Phosphorus, Dietary / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism / Q000652:urine; D011188:Potassium / Q000737:chemistry / Q000378:metabolism; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D012964:Sodium / Q000737:chemistry / Q000378:metabolism
chemical_list: D016226:Phosphorus, Dietary; D010758:Phosphorus; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium