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Redox potential: An intrinsic parameter of the rumen environment
Author(s) -
Huang Y.,
Marden J. P.,
Julien C.,
Bayourthe C.
Publication year - 2018
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/jpn.12855
Subject(s) - rumen , redox , dry matter , fermentation , zoology , food science , volatile fatty acids , chemistry , reduction potential , composition (language) , biology , inorganic chemistry , linguistics , philosophy , organic chemistry
Summary The ruminal ecosystem is a fermentative milieu which is interesting to discuss in terms of its redox status as a reflection of an intense bacterial activity. The objective of this systematic literature review is to quantitatively analyze data collected on redox potential (E h ) in the rumen and to explore relationship between ruminal E h , nature of the diet fed to ruminants, and ruminal fermentation parameters. Data obtained from 15 studies comprising 24 different diets was used in the analysis. Studies included in the data file were selected based on the criteria of: (i) the nature of the reference electrode was specified, (ii) the ruminal E h was recorded simultaneously to pH , (iii) animal body weight ( BW ) and dry matter intake ( DMI ) were reported and (iv) the composition of the diet was precisely described. Results showed a high variability in ruminal E h values. However, all recorded values are markedly negative reflecting the absence of oxygen and the strong reducing power of the rumen environment. The main factors contributing to the variation were the method of E h measurement and the nature of the diet fed to ruminants. Redox potential was positively correlated with DMI and proportion of concentrate in the diet, and tended to be positively correlated with soluble carbohydrates content. In contrast, it was negatively correlated with neutral detergent fibre from forages. The hierarchical ascendant classification discriminated two groups of diets leading to significant change in ruminal E h level. Ruminal E h was negatively correlated with pH , total volatile fatty acids produced and proportion of acetate, and positively correlated with proportion of propionate. This review revealed E h to be dependent on the diet composition and DMI , at least within the range of diets included in the database.