Models based on the Mitscherlich equation for describing typical and atypical gas production profiles obtained from in vitro digestibility studies using equine faecal inoculum

Powell, C. D., Dhanoa, M. S., Garber, A. , Murray, J.-A. M.D. , López, S., Ellis, J. L. and France, J. (2020) Models based on the Mitscherlich equation for describing typical and atypical gas production profiles obtained from in vitro digestibility studies using equine faecal inoculum. Animals, 10(2), 308. (doi: 10.3390/ani10020308)

Abstract

Two models are proposed to describe atypical biphasic gas production profiles obtained from in vitro digestibility studies. The models are extensions of the standard Mitscherlich equation, comprising either two Mitscherlich terms or one Mitscherlich and one linear term. Two models that describe typical monophasic gas production curves, the standard Mitscherlich and the France model [a generalised Mitscherlich (root-t) equation], were assessed for comparison. Models were fitted to 25 gas production profiles resulting from incubating feedstuffs with faecal inocula from equines. Seventeen profiles displayed atypical biphasic patterns while the other eight displayed typical monophasic patterns. Models were evaluated using statistical measures of goodness-of-fit and by analysis of residuals. Good agreement was found between observed atypical profiles values and fitted values obtained with the two biphasic models, and both can revert to a simple Mitscherlich allowing them to describe typical monophasic profiles. The models contain kinetic fermentation parameters that can be used in conjunction with substrate degradability information and digesta passage rate to calculate extent of substrate degradation in the rumen or hindgut. Thus, models link the in vitro gas production technique to nutrient supply in the animal by providing information relating to digestion and nutritive value of feedstuffs.

• Item Type: Articles
• Additional Information: This research in addition to the APC were funded by The Canada Research Chairs program, grant number 045867 (Natural Sciences and Engineering Research Council of Canada, Ottawa).
• Keywords: gas production technique, in vitro digestibility, Mitscherlich equation, feedstuff evaluation, fermentation kinetics, substrate degradation.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Garber, Dr Anna and Murray, Professor Jo-Anne

Creator Roles

Garber, A.: Resources, Writing – review and editing
Murray, J.-A.: Resources, Writing – review and editing

• Authors: Powell, C. D., Dhanoa, M. S., Garber, A., Murray, J.-A. M.D., López, S., Ellis, J. L., and France, J.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Animals
• Publisher: MDPI
• ISSN: 2076-2615
• ISSN (Online): 2076-2615
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Animals10(2):308
• Publisher Policy: Reproduced under a Creative Commons License