Calcium and phosphorus fractional excretion in nellore before and during pregnancy

• Autor(es):

  BORGES, ALEXANDRE SECORUN (Universidade Estadual Paulista. Departamento de Clínica, Cirurgia e Reprodução Animal);

  BARROS, BRENO PELOSO DE;

  ALVES, ANA LIZ GARCIA (Universidade Estadual Paulista. Departamento de Clínica, Cirurgia e Reprodução Animal);

  CIARLINE, PAULO CÉSAR (Universidade Estadual Paulista. Departamento de Clínica, Cirurgia e Reprodução Animal);

  BICUDO, PEDRO LUIZ (Universidade Estadual Paulista. Departamento de Clínica Veterinária);

  Kohayagawa, Aguemi (Universidade Estadual Paulista. Departamento de Clínica Veterinária).

• Fonte:

  Pesquisa Agropecuária Brasileira; volume 35, número 5, páginas 1017-1022. Maio 2000.

• Assuntos:

  bovines;

  mineral metabolism;

  urine;

  blood;

  biochemistry;

  nutritional status.

• Resumo:

  The assessment of calcium and phosphorus nutrition is difficult when using serum concentrations of these elements, because they remain within normal ranges despite a wide variation in Ca and P contents in different diets due to the high efficiency of body homeostasis process. Significant alterations are observed in chronic deficiencies when economic losses have a relevant importance. The use of fractional excretion of Ca and P allow quantitative evaluation without need of timed urine volumetric determinations. Fractional excretion ratios for Ca and P were determined using eight consecutive 45-day urine and serum sample collections performed on 22 heifers before (two samplings) and during pregnancy (six samplings). The values presented by fractional excretion of Ca and P ranged from 1.06% to 3.72% and 1.09% to 2.70%, respectively. There was a tendency to diminishing fractional excretion median values of Ca when comparing before pregnancy with values observed during pregnancy. This experiment showed that there is wide variation in Ca and P fractional excretion in different animals at the same moment and this results in difficulties to access nutritional status of these elements in cattle raised on pasture using this method.

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