Effects of different levels of fenugreek (Trigonella Foenum greacum L) seeds or extract on rumen fermentation characteristics by in vitro gas production

This research was conducted to evaluate the effects of different levels of fenugreek seeds or extract on some in vitro rumen fermentation and gas production characteristics. Samples of a total mixed ration (TMR) without any additive (control treatment), 4 diets with different levels of fenugreek seeds (2, 4, 6 and 8 percent of dry matter) and 4 diets containing different levels of fenugreek extract (0.5, 1, 1.5 and 2 percent) were incubated with rumen fluid. Gas production (GP) of feed samples were measured at hours 2, 4, 6, 8, 12, 24, 48, 72 and 96 of incubation and gas production parameters, digestibility of organic matter, short chain fatty acids (SCFA) production and metabolizable energy of the samples were estimated. Final pH and ammonia-N concentration of incubation fluids were measured at the end of incubation. Addition of fenugreek seeds had significantly increased cumulative GP and GP potential and constant rate (P<0.05). Means of SCFA were not significantly different among treatments, but rations containing fenugreek seeds had higher organic matter digestibility and metabolizable energy compared to control (P<0.05). Addition of fenugreek seeds at levels above 4 percent significantly increased pH (P<0.05), but the ammonia-N concentrations showed no significant trend in response to increasing levels of fenugreek seeds. Increasing levels of fenugreek extract up to 1 percent increased levels of cumulative GP, potential of GP, digestibility of organic matter and SCFA production and metabolizable energy significantly (P<0.05), but higher levels of it had no more effect on these parameters. Constant rate of GP was significantly higher when 1.5 percent fenugreek extract was added and increasing levels of it had increasing effect on lag time (P<0.05). Addition of 0.5 percent fenugreek extract significantly increased pH (P<0.05). Based on results of this experiment it can be concluded that the inclusion of 2 to 4 percent of fenugreek seeds or 0.5 to 1 percent of fenugreek seed extract can improve rumen fermentation characteristics, digestibility of organic matter and SCFA production.