Resumo

GALVIS GOEZ, Rubén Darío et al. EFFECT OF INCREASING LEVELS OF DIETARY NONPROTEIN NITROGEN ON GLUCONEOGENIC PRECURSORS CONCENTRATION IN BOVINE LIVER. Rev. Fac. Nac. Agron. Medellín [online]. 2010, vol.63, n.1, pp.5363-5372. ISSN 0304-2847.

In order to test the effect of growing levels of diet rumen degradable protein on hepatic concentrations of ammonia and piruvate, fifteen cows Holstein in their first one hundred post calving days were used.  They were assigned at random to three different experimental treatments, which consisted on the supply of a commercial feeding supplement without any addition of urea as a source of NNP (T0); the second treatment (T1) consisted on the supply of the same supplement with an addition of urea, so that the supply of PDR was increased 10% approximately to the requirements;finally, in the third treatment, (T2) the cows were given the same supplement which was added with enough urea so that the supply of PDR was increased 15% approximately to the requirements.  In these cows were determined hepatic concentrations of ammonia (Ahep) and pyruvate (Pyhep). The concentrations of Ahep were different among treatments, whereas the concentrations of Pihep were similar. Negative relations between Ahep and ENL, Ahep and PNDR, Ahep, and PM, were found it; while Pihep was positively related with Ahep. These results suggest the metabolizable protein use as energy source, increasing nitrogen excess and probably rest amino acids for biosynthetic process.

Palavras-chave : Ammonia; gluconeogenic precursors; nitrogen metabolism; rumen degradable protein.

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