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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Rumen phosphorus metabolism in sheep

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Dias, R. S. [1, 2] ; Lopez, S. [3] ; Silva, T. [2] ; Pardo, R. M. P. [4] ; Silva Filho, J. C. [5] ; Vitti, D. M. S. S. [2] ; Kebreab, E. [6] ; France, J. [1]
Total Authors: 8
[1] Univ Guelph, Dept Anim & Poultry Sci, Ctr Nutr Modelling, Guelph, ON N1G 2W1 - Canada
[2] Ctr Energia Nucl Agr, Anim Nutr Lab, BR-13400970 Piracicaba, SP - Brazil
[3] Univ Leon, Dept Anim Prod, CSIC, IGM, E-24071 Leon - Spain
[4] Univ Sucre, Fac Ciencias Agropecuarias, Sincelejo, Sucre - Colombia
[5] Univ Fed Lavras, Anim Res Lab, BR-37200000 Lavras, MG - Brazil
[6] Univ Manitoba, Dept Anim Sci, Winnipeg, MB R3T 2N2 - Canada
Total Affiliations: 6
Document type: Journal article
Source: JOURNAL OF AGRICULTURAL SCIENCE; v. 147, n. 4, p. 391-398, AUG 2009.
Web of Science Citations: 7

The objective of the present study was to examine the effect of the level of phosphorus (P) intake on ruminal P kinetics in sheep. Twelve Santa Ines male sheep (average body weight 36 kg) were fed a basal diet consisting of roughage (coast cross hay), concentrate mixture (cassava meal, soya bean meal and urea) and a mineral premix. The treatments consisted of the basal diet supplemented with 0, 1.5, 3 or 4.5 g/kg dry matter (DM) of mono-ammonium phosphate to provide increasing P levels representing treatments T0, T1, T2 and T3, respectively. The P content of experimental diets was 1-5; 2.0; 2.5 and 3.0 g P/kg DM, and considered highly deficient, deficient, adequate and in excess, respectively, compared with standard recommended allowances. Animals were injected with (32)P and thereafter samples of blood were collected over 7 days, while samples of rumen fluid and saliva were collected 4 and 6 days after injection. Phosphorus intake affected P concentration in ruminal fluid, whereas P concentration in saliva was not affected. The values for P turnover time in the rumen were 1.42, 1.23, 1.18 and 1.04 days, whereas values of endogenous P entry into the rumen were 1.05, 1.37, 1.53 and 1.91 g/day for T0, T 1, T2 and T3, respectively, both affected by P intake. The specific activity (SA) of P in saliva, rumen and plasma were also all affected by P intake. The relationship between saliva and rumen SA emphasizes that most endogenous P in the rumen came from saliva. The possibility of an extra P source besides saliva contributing to endogenous P in the rumen is discussed. It is concluded from the results that, regardless of P intake, the flow of endogenous P into the rumen contributes to ensure a minimum Supply of this essential element, which may be important in matching the requirements of the rumen microbes. (AU)

FAPESP's process: 04/14532-5 - Environmental impact of phosphorus excretion in livestock: quantitative analysis of flow phosphorus using bio-mathematical models
Grantee:Dorinha Miriam Silber Schmidt Vitti
Support Opportunities: Research Projects - Thematic Grants