Influence of ruminal methane on digesta retention and digestive physiology in non-lactating dairy cattle

Dittmann, M. T., Hammond, K. J., Kirton, P. ORCID: https://orcid.org/0009-0001-1941-003X, Humphries, D. J., Crompton, L. A., Ortmann, S., Misselbrook, T. H., Südekum, K.-H., Schwarm, A., Kreuzer, M., Reynolds, C. K. ORCID: https://orcid.org/0000-0002-4152-1190 and Clauss, M. (2016) Influence of ruminal methane on digesta retention and digestive physiology in non-lactating dairy cattle. British Journal of Nutrition, 116 (5). pp. 763-773. ISSN 0007-1145 doi: 10.1017/S0007114516002701

Abstract/Summary

Enteric methane (CH4) production is a side-effect of herbivore digestion, but it is unknown whether CH4 itself influences digestive physiology. We investigated the effect of adding CH4 to, or reducing it in, the reticulorumen (RR) in a 4 × 4 Latin square experiment with rumen-fistulated, non-lactating cows, with four treatments: (i) control, (ii) insufflation of CH4 (iCH4), (iii) N via rumen fistula, (iv) reduction of CH4 via administration of bromochloromethane (BCM). DM intake (DMI), apparent total tract digestibility, digesta mean retention times (MRT), rumen motility and chewing activity, spot breath CH4 emission (CH4exhal, litre/kg DMI) as well as CH4 dissolved in rumen fluid (CH4RRf, μg/ml) were measured. Data were analysed using mixed models, including treatment (or, alternatively, CH4exhal or CH4RRf) and DMI relative to body mass0·85 (rDMI) as covariates. rDMI was the lowest on the BCM treatment. CH4exhal was highest for iCH4 and lowest for BCM treatments, whereas only BCM affected (reduced) CH4RRf. After adjusting for rDMI, CH4RRf had a negative association with MRT in the gastrointestinal tract but not in the RR, and negative associations with fibre digestibility and measures of rumination activity. Adjusting for rDMI, CH4exhal had additionally a negative association with particle MRT in the RR and a positive association with rumen motility. Thus, higher rumen levels of CH4 (CH4exhal or CH4RRf) were associated with shorter MRT and increased motility. These findings are tentatively interpreted as a feedback mechanism in the ruminant digestive tract that aims at mitigating CH4 losses by shortening MRT at higher CH4.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/66285
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Animal Sciences > Animal, Dairy and Food Chain Sciences (ADFCS)- DO NOT USE
Uncontrolled Keywords	Digestion: Passage rate: Mean retention time: Motility: Rumination activity
Publisher	Cambridge University Press
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