EFFECT OF MIXTURE OF AJWAIN AND SOAPNUT PLANT EXTRACTS ON <i>INVITRO</i> RUMEN FERMENTATION, METHANE PRODUCTION AND TRUE DIGESTIBILITY OF DIET AT DIFFERENT ROUGHAGE AND CONCENTRATE RATIOS

An in vitro study evaluated the anti-methanogenic potentiality of aqueous and alcoholic plant extract mixture of ajwainseed and soapnut berries under different roughage and concentrate ratio-based diets in a 3x3 factorial design. Dried and milled plant mixture was extracted (10 g/100 ml) in three solvents, viz, water (Control), ethanol (95 %), and methanol (98 %). Substrate (200 mg) prepared by mixing wheat straw and concentrate mixture at the ratio of 30:70, 50:50 and 70:30 was taken in glass syringes (six per treatment) and incubation medium (30 ml) dispensed anaerobically. Aqueous, ethanol and methanol plant extract (0.5 ml) were taken in three dietary treatments of groups I, II, and III respectively. All the syringes were incubated at 39°C for a running duration of 24 hours and total gas production was calculated. Hundred ml of emitted gas was injected into gas chromatograph equipped with flame ionization detector for methane estimation. In vitro true digestibility of diet and ammonia nitrogen content of fermented medium were determined. Experimental data generated were analysed by adopting factorial ANOVA procedures. Results revealed that ethanol plant extract mixture had significantly (P<0.01) reduced the in vitro total gas and methane production by suppressing the true dietary digestibility of high roughage to low concentrate (70:30) based diet.