Methodology Article : Can Ruminal Reducing Power Assessed in Batch Cultures be Comparable to in Vivo Measurements?
Résumé
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.
Domaines
Sciences du Vivant [q-bio]
Origine : Accord explicite pour ce dépôt
Loading...
