Effects of harvestingtime ontannin biological activity in sambiloto (Andrographis paniculata) leaves and in vitro diet digestibility supplemented with sambiloto leaves

Abstract

This study investigated the effect of harvesting time on concentration and biological activity of tannin in Andrographis paniculata (A. paniculata) leaves and determined the in vitro rumen fermentation and digestibility of diet supplemented with A. paniculata leaves to evaluate its role as herbal supplement in ruminant’s feed. A. paniculata leaves were harvested at two time points i.e., before and after flowering phase and the samples were dried to analyze concentration and biological activity of tannin. Rice straw was used as basal diet to carry out in vitro digestibility trial. Four treatments were used including B consisting basal diet only, BBF and BAF each consisting basal diet supplemented with 1% A. paniculata leaves before and after flowering phases, respectively, and BBAF supplemented with 0.5% A. paniculata leaves before and 0.5% after flowering phase. Each treatment was carried out in five replications. Results revealed that contents (mg/g) for total tannin (20.40±1.06 vs 19.33±1.19; P<0.05) and condensed tannin (8.44±0.17 vs 5.47±0.30; P<0.01) were greater in leaves harvested after flowering compared with before flowering phase, however, no significant difference (P >0.05) on biological activity of tannins was observed between the two flowering phases. The in vitro gas production was not influenced (P > 0.05) by the supplementation of A. paniculata leaves before and after flowering phase. A. paniculata supplementation also did not influence (P>0.05) in vitro organic matter digestibility (IVOMD) and total volatile fatty acids (TVFA) values. It was concluded that the supplementation of A. paniculata leaves before and after flowering phase in the diet does not affect the digestibility.