NUTRITIVE EVALUATION OF NITROGENOUS FRACTIONS IN LEAVES OF GLIRICIDIA-SEPIUM AND CALIANDRA-CALOTHYRSUS IN RELATION TO TANNIN CONTENT AND PROTEIN-DEGRADATION BY RUMEN MICROBES IN-VITRO

A study of two fodder tree species, Gliricidia sepium and Caliandra ca lothyrsus, was undertaken to investigate the degradation of leaf prote in (crude and soluble protein) by rumen microbes during in vitro ferme ntation and the effect of total tannin content on that degradation, Di fferences in DMD and protein degradation were observed between the two leaf species. C. calothyrsus, after extraction with 70% acetone, show ed greater DMD and crude protein losses, 40% and 20% greater, respecti vely. The cumulative gas production of C. calothyrsus was increased af ter extraction with 70% acetone. It was concluded that the differences in protein degradation characteristics were mainly due to the inhibit ory effects of tannins. The apparent increased resistance of glycoprot eins to degradation appeared to be of relatively minor importance to t he nutritive value of the fodder.