Adaptation of an in vitro fermentation system conditions for the study of ruminal acidosis

Ruminal acidosis is an important disease of cattle production. The development of in vitro techniques suitable for its study would allow to reduce costs and accelerate the times to achieve results useful to contribute to the increase of production, minimally affecting animal welfare. In the present study, a “gas in vitro” method was modified using different buffer solutions (artificial saliva) to assess their buffering effect in simulated ruminal acidosis situations. Three successive tests were carried out. An artificial saliva formulated for studies that required a high buffering level (SA01) was first tested, verifying that it was not appropriate for the simulation of acidosis. Five variations in the composition of saliva SA01 were then studied and finally two saliva were tested with a different composition and elaboration methods. Differences in the evolution of pH in the fermentation systems were studied through their comparison in four times of fermentation (0, 4, 12 and 24h) with control treatments with buffered systems without triggering the simulated acidosis by Student’s t (α = 0.05) and through the comparison of the parameters obtained by means of a non-linear regression of the values obtained from each treatment, adjusting it to a descending logarithmic model. Although the three artificial salivas studied in the last experiment could meet the sought objective, the artificial saliva SA03, with a lower amount of bicarbonate and higher proportion of phosphates, was the one that presented the best behavior for the analysis of acidosis situations.