Effect of tamarind (Tamarindus indica) seed husk tannins on in vitro rumenfermentation

This study was conducted to determine the effect of tamarind seed husk (TSH ) as a source of tannin on various parameters of rumen fermentation in vitr o. The TSH contained 14% tannin (DM basis). The biological interference of TSH tannin on rumen fermentation was assessed using polyethylene glycol (PE G) 6000 as an indicator. Three compound feed mixtures (CFM) were prepared e ither without TSH (CFM-I), with 2.5% TSH (CEM-II) and with 7.5% TSH (CFM-II I). Parameters studied were in vitro gas production with PEG, rate of subst rate degradation, and microbial protein synthesis. Addition of PEG to TSH r esulted in an increase in gas production from 5.5 to 16.5 ml per 200 mg DM. Presence of TSH tannin depressed cumulative gas production by 16.8% in CFM -II, and by 29.2% in CFM-III during initial stages off fermentation (i.e. a t 8 h). Rate of substrate disappearance (T-1/2) was 14.4, 17.6 and 20.5 h i n CFM-I, CFM-II and CFM-III, respectively. Irrespective of the carbohydrate source, presence of TSH tannin improved the efficiency of microbial protei n synthesis in vitro. Thus, TSH is a natural source of tannin that can be u sed to beneficially manipulate rumen fermentation. (C) 2001 Elsevier Scienc e B.V. All rights reserved.