Low-methane yield sheep have smaller rumens and shorter rumen retention time. Issue 4 (28th February 2014)

• Record Type: Journal Article
• Authors: Goopy, John P.; Donaldson, Alastair; Hegarty, Roger; Vercoe, Philip E.; Haynes, Fay; Barnett, Mark; Oddy, V. Hutton
• Is Part Of: British journal of nutrition. Volume 111:Issue 4(2014)
• Page Start: 578
• Page End: 585
• Publication Date: 2014-02-28
• Subjects: Nutrition -- Periodicals; 572.4
• DOI: 10.1017/S0007114513002936
• Languages: English
• ISSNs: 0007-1145

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>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 CH<sub>4</sub>/kg DM intake) being low (Low MY: >1 <sc>sd</sc> below the mean; <italic>n</italic> 10) or high (High MY: >1 <sc>sd</sc> above the mean; <italic>n</italic> 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 (<italic>P</italic>= 0·001) when remeasured 1–7 months later during digesta kinetics studies. Low MY was associated with a shorter mean retention time of particulate (<italic>P</italic>< 0·01) and liquid (<italic>P</italic>< 0·001) digesta, less amounts of rumen particulate contents (<italic>P</italic>< 0·01) and a smaller rumen volume (<italic>P</italic>< 0·05), but not apparent DM digestibility (<italic>P</italic>= 0·27) or urinary allantoin excretion (<italic>P</italic>= 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 (<italic>P</italic>= 0·10). These findings indicate that the selection of ruminants for low MY may have important consequences for an animal's nutritional physiology.</p> </abstract>