Volume: 57 Issue: 2
Year: 2026, Page: 256-262, Doi: https://doi.org/10.51966/jvas.2026.57.2.256-262
Received: Dec. 15, 2025 Accepted: Jan. 21, 2026 Published: June 30, 2026
Sub-acute rumen acidosis (SARA) is a major nutritional disorder in high producing cattle, arising from excessive concentrate feeding and characterised by prolonged rumen pH depression and microbial dysbiosis. The rumen microbiome plays a central role in fibre degradation, carbohydrate fermentation, and metabolic homeostasis; therefore, PCR detection of the major carbohydrate utilising rumen bacteria and understanding the potential corrective effects of probiotics is essential for improving rumen health. The present study investigated key rumen bacterial populations in clinically healthy (control), SARA affected, and probiotic supplemented cows using PCR based detection. The Rumen pH values in stall fed cattle (5.2 to 5.8) confirmed SARA, while probiotic supplementation elevated pH toward normal physiological levels. PCR screening detected Butyrivibrio, Ruminococcus, Prevotella, and Fibrobacter sp. across all groups, reaffirming their status as core rumen bacteria. Sequencing of representative amplicons validated target specificity. Overall, the study demonstrated that SARA in cattle is marked by reduced rumen pH while probiotic supplementation helped restore pH toward normal range and supported the presence of core fibre degrading genera. PCR detection and sequence confirmation of Butyrivibrio, Ruminococcus, Prevotella, and Fibrobacter sp. across all groups highlighted their fundamental role in rumen function. These findings reinforced the importance of maintaining microbial balance to prevent SARA and promote optimal rumen health.
Keywords: Sub-acute rumen acidosis, Butyrivibrio, Fibrobacter, Ruminococcus, Prevotella
Bach, A., Iglesias, C., and Devant, M. (2007). Daily rumen pH pattern of loose-housed dairy cattle as affected by feeding pattern and live yeast supplementation. Animal Feed Science and Technology, 136(1-2): 146-153. https://doi.org/10.1016/j.anifeedsci.2006.09.011
Bekele, A. Z., Koike, S., and Kobayashi, Y. (2010). Genetic diversity and diet specificity of ruminal Prevotella revealed by 16S rRNA gene-based analysis. FEMS microbiology letters, 305(1): 49-57. https://doi.org/10.1111/j.1574-6968.2010.01911.x
Bi, Y., Zeng, S., Zhang, R., Diao, Q., and Tu, Y. (2018). Effects of dietary energy levels on rumen bacterial community composition in Holstein heifers under the same forage to concentrate ratio condition. BMC microbiology, 18(1): 69. https://doi.org/10.1186/s12866-018-1213-9
Chung, Y. H., Walker, N. D., McGinn, S. M., and Beauchemin, K. A. (2011). Differing effects of 2 active dried yeast (Saccharomyces cerevisiae) strains on ruminal acidosis and methane production in nonlactating dairy cows. Journal of Dairy Science, 94(5): 2431-2439. https://doi.org/10.3168/jds.2010-3277
Dohme, F., DeVries, T. J., and Beauchemin, K. A. (2008). Repeated ruminal acidosis challenges in lactating dairy cows at high and low risk for developing acidosis: Ruminal pH. Journal of dairy science, 91(9): 3554-3567. https://doi.org/10.3168/jds.2008-1264
Fernando, S. C., Purvis, H. T., Najar, F. Z., Sukharnikov, L. O., Krehbiel, C. R., Nagaraja, T. G., Roe, B.A. and Desilva, U. J. A. E. M. (2010). Rumen microbial population dynamics during adaptation to a high-grain diet. Applied and environmental microbiology, 76(22): 7482-7490. http://dx.doi.org/10.1128/AEM.00388-10
Garrett, E. F., Pereira, M. N., Nordlund, K. V., Armentano, L. E., Goodger, W. J., and Oetzel, G. R. (1999). Diagnostic methods for the detection of subacute ruminal acidosis in dairy cows. Journal of Dairy Science, 82(6): 1170-1178. https://doi.org/10.3168/jds.S0022-0302(99)75340-3
Khafipour, E., Li, S., Plaizier, J. C., and Krause, D. O. (2009). Rumen microbiome composition determined using two nutritional models of subacute ruminal acidosis. Applied and environmental microbiology, 75(22): 7115-7124. https://doi.org/10.1128/AEM.00739-09
Krause, D. O., Dalrymple, B. P., Smith, W. J., Mackie, R. I., and McSweeney, C. S. (1999). 16S rDNA sequencing of Ruminococcus albus and Ruminococcus flavefaciens: design of a signature probe and its application in adult sheep. Microbiology, 145(7): 1797-1807. https://doi.org/10.1099/13500872-145-7-1797
Li, S., Danscher, A. M., and Plaizier, J. C. (2013). Subactue ruminal acidosis (SARA) in dairy cattle: new developments in diagnostic aspects and feeding management. Can. J. Anim. Sci, 94(1): 353-364.
Liu, K., Zhang, Y., Yu, Z., Xu, Q., Zheng, N., Zhao, S., Huang, G. and Wang, J. (2021). Ruminal microbiota-host interaction and its effect on nutrient metabolism. Animal Nutrition, 7(1): 49-55. https://doi.org/10.1016/j.aninu.2020.12.001
Mei, S., He, G., Chen, Z., Zhang, R., Liao, Y., Zhu, M., Xu, D., Shen, Y., Zhou, B., Wang, K. and Chen, C. (2023). Probiotic-fermented distillers grain alters the rumen microbiome, metabolome, and enzyme activity, enhancing the immune status of finishing cattle. Animals, 13(24): 3774. https://doi.org/10.3390/ani13243774
Petri, R. M., Schwaiger, T., Penner, G. B., Beauchemin, K. A., Forster, R. J., McKinnon, J. J., and McAllister, T. A. (2013). Characterization of the core rumen microbiome in cattle during transition from forage to concentrate as well as during and after an acidotic challenge. PLoS ONE, 8(12): e83424. https://doi.org/10.1371/journal.pone.0083424
Sadan, T., Aravindakshan, T. V., Radhika, G., Anand, L. F., and Ally, K. (2020). Metagenomic analysis exploring taxonomic diversity of rumen microbial communities in Vechur and crossbred cattle of Kerala state, India. Journal of Applied Genetics, 61(2): 287-297. https://doi.org/10.1007/s13353-020-00547-7
Stevenson, D. M., and Weimer, P. J. (2007). Dominance of Prevotella and low abundance of classical ruminal bacterial species in the bovine rumen revealed by relative quantification real-time PCR. Applied microbiology and biotechnology, 75(1): 165-174. https://doi.org/10.1007/s00253-006-0802-y
Tajima, K., Aminov, R. I., Nagamine, T., Ogata, K., Nakamura, M., Matsui, H., and Benno, Y. (1999). Rumen bacterial diversity as determined by sequence analysis of 16S rDNA libraries. FEMS microbiology ecology, 29(2): 159-169. https://doi.org/10.1111/j.1574-6941.1999.tb00607.x
Tajima, K., Aminov, R. I., Nagamine, T., Matsui, H., Nakamura, M., and Benno, Y. (2001). Diet-dependent shifts in the bacterial population of the rumen revealed with real-time PCR. Applied and environmental microbiology, 67(6): 2766-2774. https://doi.org/10.1128/AEM.67.6.2766-2774.2001
Wang, Z., Elekwachi, C., Jiao, J., Wang, M., Tang, S., Zhou, C., Tan, Z and Forster, R. J. (2017). Changes in metabolically active bacterial community during rumen development, and their alteration by rhubarb root powder revealed by 16S rRNA amplicon sequencing. Frontiers in microbiology, 8: 159. https://doi.org/10.3389/fmicb.2017.00159
Zhu, Z., Hang, S., Mao, S., and Zhu, W. (2014). Diversity of Butyrivibrio group bacteria in the rumen of goats and its response to the supplementation of garlic oil. Asian-Australasian journal of animal sciences, 27(2): 179. https://doi.org/10.5713/ajas.2013.13373
© 2026 Thomas John et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Thomas John, M., Mani, B.K., Priya, P.M., Sankar, S., Ajith, K.S., Bunglavan, S.J. and Gleeja, V.L. 2025. Molecular profiling of major carbohydrate utilising rumen bacteria in lactating cows with sub-acute rumen acidosis. Journal of Veterinary and Animal Sciences, 57(2),256-262 https://doi.org/10.51966/jvas.2026.57.2.256-262