Resumen

GODOY, Susmira; CHICCO, Claudio  y  REQUENA, Fanny. Fosfatos sedimentarios venezolanos en la alimentación de ovinos. INCI [online]. 2002, vol.27, n.9, pp.482-488. ISSN 0378-1844.

True absorption coefficients and phosphorus kinetics, as well as fluorine retention, were determined in lambs fed with the Venezuelan sedimentary phosphates most commonly used, Riecito (RIO), Monte Fresco (MONTE), with a fertilizer (triple super-phosphate; SPT) and with dicalcium phosphate (DICAL) as a control. Sixteen male lambs (West African), with 25kg ±1.76 average body weight were randomly assigned in groups of four to the four treatments (phosphates). Lambs were kept in metabolism crates during 21 days, 14 for adaptation and 7 to record feed intake and excreta. To the basal diet, containing 0.12% P, 14.3% estimated crude protein (PCE) and 2,97 Mcal estimated metabolizable energy (EME)/kg, both calculated on the basis of chemical composition of diet ingredients, two levels of added inorganic phosphorus (0.05 and 0.20%) were added from the different phosphates to measure apparent absorption, apparent net retention, utilization eficiency and true absorption. The lambs fed with 0.20% added phosphorus were intravenously dosed with 200 µC of 32P to measure fecal endogenous phosphorus and kinetics of 32P. An isotopic dilution technique was used to measure true absorption. At 0.20% added P, absorption measurements were greater (P<0.05) for DICAL and SFT than RIO and MONTE. Metabolic fecal phosphorus, at the level of 0,20% added phosphorus, was greater (P<0.05) for DICAL and SFT than RIO and MONTE. Blood clearance of 32P from the central pool showed a bi-exponential rate, higher for DICAL and RIO and lower for SFT and MONTE. Half-time (minutes) 32P removal for the fast rate was lower for DICAL and RIO and higher for SFT and MONTE. Apparent average net retention of fluorine was greater (P<0.50) for SFT, intermediate for MONTE and lower for RIO. Fluorine total fecal excretion (%) was greater for the sedimentary phosphates and lower for SFT.

Palabras clave : Fósforo ; Ovinos ; Flúor .