Effects of chicory inulin on ruminal fermentation in vitro

The objective of this study was to investigate the effects of spray dried inulin powder from chicory roots of different origins on in vitro ruminal fermentation. For this purpose, two long-term experiments were made with the Rumen Simulation Technique (Rusitec), in which the fermentation of a mixed ration of hay (5 g/d) and concentrate (4 g/d) was compared with the fermentation of the same diet in the presence of chicory inulin. The Rusitec system consisted of nine vessels (fermenters): three of them received daily 1.5 g of inulin powder from the Netherlands, three vessels received daily 1.5 g of inulin powder from Denmark and three vessels received no additives (control) in experiment I. This experimental setup was repeated in experiment II. However, 1.5 g of inulin from China and 1.5 g inulin from Germany were tested. Compared to control vessels, ruminal pH was significantly lower in the vessels supplemented with Chinese and German inulin. Dutch and Danish inulin had no effect on ruminal pH. Danish and Chinese inulin resulted in an increase of total-SCFA (short-chain fatty acids), acetate, propionate, butyrate, isovalerate and valerate production whereas Dutch inulin led to an increase in butyrate, iso-valerate and valerate production only. Addition of German inulin caused a significant increase in the production of total-SCFA, acetate, butyrate, iso-valerate and valerate in the rumen fluid. Compared to control, all inulin preparations decreased NH3-N concentrations in the fermentation vessels. The digestibility of organic matter was not statistically influenced by Chinese and German inulin. However, Dutch and Danisch inulin decreased significantly the digestibility of organic matter compared to control vessels. These results indicated that, in relation to its origin, inulin stimulated ruminal fermentation and it was especially effective at decreasing ruminal ammonia concentration in vitro.