<div>Background: Rice feeding followed in Tamil Nadu for dairy cattle induces acidosis and the effect of acidosis studies through in vitro techniques is desirable to reduce the animal experiment. Since Mc Dougall Buffer neutralizes acidity produced on incubation with rice (Oriza sativa) in semi continuous culture, it is difficult to mimic acidosis in RUSITEC. Hence a study was conducted in RUSITEC with cooked rice incubated for 24 hours to evaluate the effect of diluting Mc Dougall buffer to establish rumen acidosis (pH &lt; 5.8).&nbsp; 
 
Methods: Two treatments were followed with undiluted Mc Dougall Buffer (MDB) and diluting Mc Dougall Buffer (MMDB) as per Mickdam et al. (2016) in RUSITEC experiments with six replicates for each treatment. This experiment was conducted with equivalent weight of test material (Cooked rice on DMB). The pH of artificial buffer was maintained at 7.4 during start of incubation for both buffers. 
 
Result: The rumen fermentation pattern for establishment of onset of acidosis due to over feeding of cooked rice was evinced by the onset of acidosis (&lt;5.8 pH) recorded at 3 hours of incubation in MMDB infusion and at 18 hours of incubation in MDB infusion. The concentration of NH3-N declined after acidosis induction; however, it reached its minimum in MMDB at significant difference (p&lt;0.05) than MDB at all incubation hours. Total gas production (Methane and Carbon dioxide) was reduced with MMDB incubation. The CH4 proportion declined strongly (p&lt;0.01) at all incubation hours in MMDB than MDB. The production of volatile fatty acid was reduced significantly (p&lt;0.05) in MMDB at all incubation period compared with MDB. This was based on a significant decrease in the acetate production (p&lt;0.05), an increase in the propionate and butyrate production (p&lt;0.05). Acidosis challenge resulted in significantly (p&lt;0.01) elevated lactate levels in MMDB at all incubation hours which remained high at 24 hours of incubation. Compared to MDB condition, the LPS concentration was largely elevated (p&lt;0.01), by 36% on average till 12 hours of incubation, due to severe acidosis condition (pH 4.9) created by MMDB. The early occurrence of acidosis condition in MMDB, increased significantly (p&lt;0.01) gram positive organisms in the rumen. The MMDB infusion showed a strong effect on degradation of DM, OM and N and it was decreased, similarly the degradation rate of DM and N was lowest. This study proves that the MMDB is the suitable acidosis inducing buffer for establishing the in vitro models to cooked rice.</div>

<div>&nbsp;</div>

Evaluation of Suitability of Buffer to Induce Acidosis on Rice (Oriza sativa) based Diet in RUSITEC