Author(s)

Yayu Huang^1,2, Jean Philippe Marden³, Chaouki Benchaar⁴, Christine Julien³, Eric Auclair³, Corine Bayourthe^1,2*

¹Physiologie et Systèmes d’ Elevage, UMR1388 Génétique, Université de Toulouse INPT ENSAT, Castanet-Tolosan, France.
²Physiologie et Systèmes d’ Elevage, UMR1388 Génétique, INRA, Castanet-Tolosan, France.
³Phileo Lesaffre Animal Care, Marcq-en-Baroeul, France.
⁴Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, Canada.

The ruminal redox potential (E_h) can reflect the microbiological activity and dynamics of fermentation in the rumen. It might be an important indicator of rumen fermentation in combination with pH. However, the ruminal E_h has been rarely studied in dairy cows due to the difficulty of its measurement, and the relationship between ruminal E_h and pH is not clear. The objective of this study was to investigate the relationship between ruminal E_h and pH of dairy cows by meta-analysis of systematic measurements from different experiments. A database was constructed from 22 experiments on cannulated dairy cattle including 57 dietary treatments. The ruminal pH and E_h were measured without air contact between 0 and 8 h post-feeding. The results demonstrated a quadratic correlation between ruminal E_h and pH with a reliable within-animal variation (E_h = -1697 + 540.7 pH -47.7 pH², n_observation = 70, n_animal = 26, P < 0.001, RMSE = 56, AIC = 597). The dietary characteristics (NDF, NDFf, OM, starch, degradable starch, soluble sugars contents, and the dietary ionic balance) influencing the ruminal pH also affected the ruminal E_h, but not always to the same extent. Some of them still influenced the relationship between ruminal E_h and pH. While the mechanism of the interaction between ruminal E_h and pH remains to be elucidated, it would be interesting to associate E_h to microbial profile, ruminal VFA concentration and milk production performance in future studies.

Redox Potential, pH, Rumen, Diet, Dairy Cow

Huang, Y. , Philippe Marden, J. , Benchaar, C. , Julien, C. , Auclair, E. and Bayourthe, C. (2017) Quantitative Analysis of the Relationship between Ruminal Redox Potential and pH in Dairy Cattle: Influence of Dietary Characteristics. Agricultural Sciences, 8, 616-630. doi: 10.4236/as.2017.87047.