Low-methane yield sheep have smaller rumens and shorter rumen retention time

Goopy, John P; Donaldson, Alastair; Hegarty, Roger; Vercoe, Phillip E; Haynes, Fay Emma Milton; Barnett, Mark; Oddy, Hutton

doi:10.1017/S0007114513002936

Author(s)

Goopy, John P

Donaldson, Alastair

Hegarty, Roger

Vercoe, Phillip E

Haynes, Fay Emma Milton

Barnett, Mark

Oddy, Hutton

Publication Date

2014

Abstract

In the present study, following the measurement of methane emissions from 160 mature ewes three times, a subset of twenty ewes was selected for further emission and physiological studies. Ewes were selected on the basis of methane yield (MY: g CH₄/kg DM intake) being low (Low MY: >1 sd below the mean; n 10) or high (High MY: >1 sd above the mean; n 10) when fed a blended chaff ration at a fixed feeding level (1·2-fold maintenance energy requirements). The difference between the Low- and High-MY groups observed at the time of selection was maintained (P= 0·001) when remeasured 1-7 months later during digesta kinetics studies. Low MY was associated with a shorter mean retention time of particulate (P< 0·01) and liquid (P< 0·001) digesta, less amounts of rumen particulate contents (P< 0·01) and a smaller rumen volume (P< 0·05), but not apparent DM digestibility (P= 0.27) or urinary allantoin excretion (P= 0·89). Computer tomography scanning of the sheep's rumens after an overnight fast revealed a trend towards the Low-MY sheep having more clearly demarcated rumen gas and liquid phases (P= 0·10). These findings indicate that the selection of ruminants for low MY may have important consequences for an animal's nutritional physiology.

Citation

British Journal of Nutrition, 111(4), p. 578-585

ISSN

1475-2662

0007-1145

Link

https://hdl.handle.net/1959.11/14642

Language

en

Publisher

Cambridge University Press

Title

Low-methane yield sheep have smaller rumens and shorter rumen retention time

Type of document

Journal Article

Entity Type

Publication

Author(s)	Goopy, John P Donaldson, Alastair Hegarty, Roger Vercoe, Phillip E Haynes, Fay Emma Milton Barnett, Mark Oddy, Hutton
Publication Date	2014
Abstract	In the present study, following the measurement of methane emissions from 160 mature ewes three times, a subset of twenty ewes was selected for further emission and physiological studies. Ewes were selected on the basis of methane yield (MY: g CH₄/kg DM intake) being low (Low MY: >1 sd below the mean; n 10) or high (High MY: >1 sd above the mean; n 10) when fed a blended chaff ration at a fixed feeding level (1·2-fold maintenance energy requirements). The difference between the Low- and High-MY groups observed at the time of selection was maintained (P= 0·001) when remeasured 1-7 months later during digesta kinetics studies. Low MY was associated with a shorter mean retention time of particulate (P< 0·01) and liquid (P< 0·001) digesta, less amounts of rumen particulate contents (P< 0·01) and a smaller rumen volume (P< 0·05), but not apparent DM digestibility (P= 0.27) or urinary allantoin excretion (P= 0·89). Computer tomography scanning of the sheep's rumens after an overnight fast revealed a trend towards the Low-MY sheep having more clearly demarcated rumen gas and liquid phases (P= 0·10). These findings indicate that the selection of ruminants for low MY may have important consequences for an animal's nutritional physiology.
Citation	British Journal of Nutrition, 111(4), p. 578-585
ISSN	1475-2662 0007-1145
Link	https://hdl.handle.net/1959.11/14642
Language	en
Publisher	Cambridge University Press
Title	Low-methane yield sheep have smaller rumens and shorter rumen retention time
Type of document	Journal Article
Entity Type	Publication

Low-methane yield sheep have smaller rumens and shorter rumen retention time

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