INRA, UMR1388 Genetic, Physiology and Breeding System, Castanet-Tolosan, France. Lesaffre Feed Additives, 282 Avenue de la Marne, Marcq-en-Baroeul, France.
In ruminant field of digestive research, the appeal to methods of less invasive studies and reproducing the in vivo conditions is essential. The objective of the present study was to determine whether the conditions created with the proposed in vitro batch culture was an accurate reproduction of the physico-chemical and fermentative ruminal conditions observed in vivo. Two experiments were conducted to compare ruminal reducing power measured in vitro, i.e. in batch cultures or, in vivo i.e. in live animals: dairy cows at maintenance (Experiment 1) and lactating dairy cows (Experiment 2). In Experiment 1, at the beginning of incubation period, in vitro redox potential (Eh), pH and Clark’s exponent (rH) values were significantly higher than in vivo (+42 mV, +0.25 and +1.9, respectively) whereas volatile fatty acids (VFA) contents were 2.6 fold lower on average. At the end of incubation, Eh, rH values and VFA contents were similar between both methods whereas pH still remained different. In Experiment 2, at the beginning and at the end of incubation period, in vitro Eh, pH and rH values differed significantly than in vivo. As a result, the in vitro method did not provide a tool to evaluate accurately the level of the reducing status of ruminal milieu compared with in vivo measurement. Nonetheless, it provided strong reducing conditions after 8 h of incubation with levels of rH relatively closed to those observed in vivo. In vitro batch culture could be a good alternative to in vivo trials for a screening approach from an ethic and economic point of view in ruminant field of research.
Julien, C. , Marden, J. , Troegeler-Meynadier, A. and Bayourthe, C. (2014) Methodology Article: Can Ruminal Reducing Power Assessed in Batch Cultures be Comparable to in Vivo Measurements?. Journal of Analytical Sciences, Methods and Instrumentation, 4, 80-86. doi: 10.4236/jasmi.2014.43011.
[1] Tomlinson, J.W. and Kilmartin, P.A. (1997) Measurement of the Redox Potential of Wine. Journal of Applied Electrochemistry, 27, 1125-1134. http://dx.doi.org/10.1023/A:1018407230924 [2] De Laune, R.D. and Reddy, K.R. (2005) Redox Potential. In: Hillel, D., Ed., Encyclopedia of Soils in the Environment, Academic Press, Elsewier Ltd., 366-371. [3] Brasca, M., Morandi, S., Lodi, R. and Tamburini, A. (2007) Redox Potential to Discriminate among Species of Lactic Acid Bacteria. Journal of Applied Microbiology, 103, 1516-1524.
http://dx.doi.org/10.1111/j.1365-2672.2007.03379.x [4] Julien, C., Marden, J.P., Moncoulon, R. and Bayourthe, C. (2010) Redox Potential Measurement: A New Way to Explore Ruminal Metabolism. Journal of Animal Science, 88, 578. [5] Baldwin, B.L. and Emery, R.S. (1960) Investigation of the Oxidation-Reduction Potential of Rumen Contents. Journal of Dairy Science, 43, 506-511. http://dx.doi.org/10.3168/jds.S0022-0302(60)90193-4 [6] Barry, T.N., Thompson, A. and Armstrong, D.G. (1977) Rumen Fermentation Studies on Two Constrasting Diets. 1. Some Characteristics of the in Vivo Fermentation, with Special Reference to the Composition of the Gas Phase, Oxidation/Reduction State and Volatile Fatty Acid Proportions. Journal of Agricultural Science, 89, 183-195.
http://dx.doi.org/10.1017/S0021859600027362 [7] Marounek, M., Bartos, S. and Kalachnyuk, G.I. (1982) Dynamics of the Redox Popential and rH of the Rumen Fluid of goats. Physiologia Bohemoslova, 31, 369-374. [8] Julien, C., Marden, J.P., Bonnefont, C., Moncoulon, R., Auclair, E., Monteils, V. and Bayourthe, C. (2010) Effects of Varying Proportions of Concentrates on Ruminal-Reducing Power and Bacterial Community Structure in Dry Dairy Cows fed Hay-Based Diets. Animal, 4, 1641-1646.
http://dx.doi.org/10.1017/S1751731110000972 [9] Julien, C., Marden, J.P., Moncoulon, R., Auclair, E. and Bayourthe, C. (2010) Ruminal Redox Potential in Dairy Cows Regarding Diet Composition and Live Yeast Supplementation: A Modelling Approach. Proceedings of the 3rd International EAAP Symposium on Energy and Protein Metabolism and Nutrition, Parma, 6-10 September 2010, 551. [10] Mathieu, F., Jouany, J.P., Senaud, J., Bohatier, J., Bertin, G. and Mercier, M. (1996) The Effect of Saccharomyces cerevisiae and Aspergillus oryzae on Fermentations in the Rumen of Faunated and Defaunated Sheep: Protozoal and Probiotics Interactions. Reproduction Nutrition Développement, 36, 271-287. http://dx.doi.org/10.1051/rnd:19960305 [11] Marden, J.P., Julien, C., Monteils, V., Auclair, E., Moncoulon, R. and Bayourthe, C. (2008) How Does Live Yeast Differ from Sodium Bicarbonate to Stabilize Ruminal pH in High-Yielding Dairy Cows? Journal of Dairy Science, 91, 3528-3535. http://dx.doi.org/10.3168/jds.2007-0889 [12] Marden, J.P., Bayourthe, C., Enjalbert, F. and Moncoulon, R. (2005) A New Device for Measuring Kinetics of Ruminal pH and Redox Potential in Dairy Cows. Journal of Dairy Science, 88, 277-281.
http://dx.doi.org/10.3168/jds.S0022-0302(05)72685-0 [13] Farghali, M.M. and Iben, C. (2009) Effect of Heat Treatment of Canola Seed and Canola Meal on Rumen Fermentation in Vitro. Proceedings of the 13rd Congress of the ESVCN, Oristano, 15-17 October 2009, 132. [14] Czerkawski, J.W. and Breckenridge, G. (1977) Design and Development of a Long-Term Rumen Stimulation Technique (Rusitec). British Journal of Nutrition, 38, 371-384. http://dx.doi.org/10.1079/BJN19770102 [15] Marounek, M., Roubal, P. and Bartos, S. (1987) The Redox Potential, rH and pH Values in the Gastrointestinal Tract of Small Ruminants. Physiologica Bohemoslova, 36, 71-73. [16] Troegeler-Meynadier, A., Nicot, M.C., Bayourthe, C., Moncoulon, R. and Enjalbert, F. (2003) Effects of pH and Concentrations of Linoleic and Linolenic Acids on Extent and Intermediates of Ruminal Biohydrogenation in Vitro. Journal of Dairy Science, 86, 4054-4063. http://dx.doi.org/10.3168/jds.S0022-0302(03)74017-X [17] Julien, C., Troegeler-Meynadier, A., Marden, J.P., Enjalbert, F. and Bayourthe, C. (2009) In Vivo and in Vitro Measurements of Ruminal Redox Potential: A Comparative Study. Journal of Animal Science, 87, 477. [18] Craig, W.M., Hong, B.J., Broderick, G.A. and Bula, R.J. (1984) In Vitro Inoculum Enriched with Particle-Associated Microorganisms for Determining Rates of Fiber Digestion and Protein Degradation. Journal of Dairy Science, 67, 2902-2909. http://dx.doi.org/10.3168/jds.S0022-0302(84)81653-7