The present study was conducted to assess the chemical composition and in vitro nutritional worth of total mixed rations (with R:C ratio of 50:50) containing graded levels of Tinospora cordifolia stem powder. T. cordifolia was added to the total mixed ration (TMR) at the levels of 0%, 1%, 2%, 3%, 4% and 5% (on DM basis) to formulate six TMRs designated as TMR1, TMR2, TMR 3, TMR 4, TMR 5 and TMR 6, respectively. No significant difference was observed in net gas production, truly degraded substrate, partitioning factor, OM digestibility, NDF digestibility, microbial mass production, efficiency of microbial mass production, short chain fatty acids and metabolizable energy among the total mixed rations tested. The ammoniacal nitrogen (NH3-N, mg/dl) was higher (P<0.05) in TMR 1 (26.50) and lower (P<0.05) in TMR 6 (20.60) than other TMRs evaluated. The in vitro methane production was significantly (P<0.05) lower in TMR 3 containing 2% T. cordifolia on DM basis than control TMR (TMR 1). Thus, T. cordifolia stem powder incorporated at the rate of 2% of DM in the diet of ruminants has the potential to reduce methane production.

Highlights

• There was no effect on nutrient digestibility and microbial mass production of TMRs containing graded levels of Tinospora cordifolia.
• Ammonia-N showed a declining trend with increasing level of Tinospora cordifolia in total mixed ration.
• The in vitro methane production was reduced (P<0.05) in TMR containing 2% T. cordifolia on DM basis.