Effect of a Blend of Commercial Ajwain (Trachyspermum ammi) Oil and Nitrate on the Fermentation and Microbial Profile of Buffalo Rumen

In order to ascertain the effects of supplementation of a blend of ajwain (Trachyspermum ammi) oil and nitrate on rumen fermentation and microbial profile, three rumen-fistulated buffaloes were used in a 3x3 switch over design. The dietary treatments involved feeding of a basal diet alone without additive (Control) or the same supplemented with a mixture of sodium nitrate and potassium nitrate (1:1), replacing 15% basal diet CP, along with ajwain oil at 0.75 (T1) and 1.5 (T2) ml/100 kg BW. Further, in vitro gas production test was carried out using the inoculum form thethree groups of buffaloes taking different hays (maize, oat and berseem), straws (wheat straw, paddy straw and sugarcane bagasse) and total mixed rations (TMRs) with different concentrate: wheat straw ratio namely, 20:80, 35:65 and 50:50, as substrates namely. The rumen fermentation parameters, as well as the rumen microbial profile, were similar (P>0.05) in all the three groups. In vitro methane production was decreased by 21.6, 28.39, and 16.5 per cent in hays, straws and TMRs, respectively, with the inocula of T2 animals than control. The in vitro true digestibility was higher in case of TMRs as the substrate with the inocula of T1 and T2 animals as compared to control. It is concluded that the blend of ajwain oil and nitrate tested may be tested further as a potential feed supplement for methane mitigation from livestock maintained on fibrous diet as it decreased methane production with an improvement in feed digestibility and without any adverse effect on rumen microbial fermentation and microbial profile.