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Individual-level correlations of rumen volatile fatty acids with enteric methane emissions for ranking methane yield in sheep fed fresh pasture
- Source :
- Jonker, A, Hickey, S, Boma, P, Woyimo Woju, C, Sandoval, E, Maclean, S, Garciá Rendón Calzada, M, Yu, W, Lewis, S, Janssen, P H, McEwan, J C & Rowe, S 2020, ' Individual-level correlations of rumen volatile fatty acids with enteric methane emissions for ranking methane yield in sheep fed fresh pasture ', Animal Production Science, vol. 61, no. 3, pp. 208-214 . https://doi.org/10.1071/AN20128
- Publication Year :
- 2021
- Publisher :
- CSIRO Publishing, 2021.
-
Abstract
- Context Total ruminal volatile fatty acids (VFA) or acetate concentrations were previously found to be moderate correlated proxies to select sheep that are genetically low methane (CH4) emitters. However, this was based on trials, with sheep fed lucerne pellets at a fixed feeding level, which is different from pastoral farming conditions in New Zealand, where the correlated proxy would be applied. Aim To determine repeatability and individual-level correlation of rumen VFAs with CH4 emissions in sheep fed ad libitum cut pasture in three and four repeated periods in Experiments 1 and 2 respectively. Sheep in Experiment 1 were also fed lucerne pellets at 2.0 × maintenance-energy requirements in two periods. Methods Methane emissions were measured from 96 and 72 animals, in Experiments 1 and 2 respectively, in respiration chambers and rumen samples were collected via oral stomach tubing before morning feeding. Repeatability estimates between periods within feed and experiment serve as an upper threshold for the estimate of heritability and ri estimates are a proxy for genetic correlation. Key results Methane (g/day) production and yield (g/kg dry-matter intake) were low to moderately repeatable traits on pasture across periods (0.58 and 0.39 for CH4 production and 0.43 and 0.32 for yield in Experiments 1 and 2 respectively). On pasture, repeatability was generally greater for VFA proportions (0.13–0.32) than for VFA concentrations (0.02–0.24), while the opposite was the case on lucerne pellets. Rumen propionate as a proportion of total VFA had strong negative ri (−0.82 and −0.87) and acetate:propionate ratio (A:P; 0.82 and 0.78) and (acetate + butyrate):(propionate + valerate) ratio (AB:PV; 0.84 and 0.82) had a strong positive ri with CH4 yield in sheep fed cut pasture, while the ri of total ruminal VFA (−0.13 and 0.35) and acetate (−0.08 and 0.38) concentrations with CH4 yield were only moderate and non-significant. Conclusion The VFA traits propionate proportion and A:P and AB:PV ratios had strong individual-level correlations with CH4 yield in sheep fed pasture ad libitum, suggesting that they would be useful correlated proxies to rank sheep CH4 yields.
- Subjects :
- chemistry.chemical_classification
0303 health sciences
geography
geography.geographical_feature_category
short-chain fatty acids
0402 animal and dairy science
Pellets
04 agricultural and veterinary sciences
Repeatability
Valerate
040201 dairy & animal science
Pasture
Genetic correlation
03 medical and health sciences
Rumen
Animal science
chemistry
Respiration
Propionate
Animal Science and Zoology
reticulo-rumen fermentation
correlated proxy
indicator trait
030304 developmental biology
Food Science
Subjects
Details
- ISSN :
- 18360939
- Volume :
- 61
- Database :
- OpenAIRE
- Journal :
- Animal Production Science
- Accession number :
- edsair.doi.dedup.....104d4ac9010d040486b8e726f34ad827