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- Danielsson, Rebecca, et al.
(författare)
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Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol-An in vitro evaluation
- 2014
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 97, s. 5729-5741
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate the effect of cashew nut shell extract (CNSE) and glycerol (purity >99%) on enteric methane (CH4) production and microbial communities in an automated gas in vitro system. Microbial communities from the in vitro system were compared with samples from the donor cows, in vivo. Inoculated rumen fluid was mixed with a diet with a 60:40 forage:concentrate ratio and, in total, 5 different treatments were set up: 5 mg of CNSE (CNSE-L), 10 mg of CNSE (CNSE-H), 15 mmol of glycerol/L (glycerol-L), and 30 mmol of glycerol/L (glycerol-H), and a control without feed additive. Gas samples were taken at 2, 4, 8, 24, 32, and 48 h of incubation, and the CH4 concentration was measured. Samples of rumen fluid were taken for volatile fatty acid analysis and for microbial sequence analyses after 8, 24, and 48 h of incubation. In vivo rumen samples from the cows were taken 2 h after the morning feeding at 3 consecutive days to compare the in vitro system with in vivo conditions. The gas data and data from microbial sequence analysis (454 sequencing) were analyzed using a mixed model and principal components analysis. These analyses illustrated that CH4 production was reduced with the CNSE treatment, by 8 and 18%, respectively, for the L and H concentration. Glycerol instead increased CH4 production by 8 and 12%, respectively, for the L and H concentration. The inhibition with CNSE could be due to the observed shift in bacterial population, possibly resulting in decreased production of hydrogen or formate, the methanogenic substrates. Alternatively the response could be explained by a shift in the methanogenic community. In the glycerol treatments, no main differences in bacterial or archaeal population were detected compared with the in vivo control. Thus, the increase in CH4 production may be explained by the increase in substrate in the in vitro system. The reduced CH4 production in vitro with CNSE suggests that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows.
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| 4. |
- Huhtanen, Pekka, et al.
(författare)
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Evaluation of the Nordic dairy cow model Karoline in predicting methane production
- 2012
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Ingår i: Acta Agriculturae Scandinavica, Section A - Animal Science. - : Informa UK Limited. - 0906-4702 .- 1651-1972. ; 62, s. 295-299
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate the Nordic dairy cow model Karoline using a synthetic data-set. The data-set included 120 diets comprised of one of the five grass silages differing in digestibility, red clover silage and concentrate ingredients. The relationship between total methane (CH4) production predicted by Karoline model and that estimated from empirical equation (=observed'), showed that Karoline model over-predicted CH4 production by 30 L/d (P<0.01) with the mean bias having the greatest contribution (59%) of mean squared prediction error (MSPE). The proportion of random error of MSPE was 40%, whereas the contribution of linear bias was small and non-significant (P = 0.11). The residuals were significantly related to dietary crude protein (CP) concentration. It is concluded that Karoline model predicts CH4 production with a reasonable accuracy and that it is a useful tool to understand quantitatively mechanisms influencing CH4 production.
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| 7. |
- Krizsan, Sophie Julie, et al.
(författare)
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Comparison of some aspects of the in situ and in vitro methods in evaluation of neutral detergent fiber digestion
- 2013
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 91, s. 838-847
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the present study was to compare digestion rates (k(d)) of NDF for different feeds estimated with the in situ method or derived from an automated gas in vitro system. A meta-analysis was conducted to evaluate how in situ derived k(d) of NDF related to in vivo digestibility of NDF. Furthermore, in vitro true digestibility of the feed samples incubated within filter bags or dispersed in the medium was compared, and k(d) for insoluble and soluble components of those feeds were estimated. Four different concentrates and 4 forages were used in this study. Two lactating Swedish Red cows fed a diet of 60% grass silage and 40% concentrate on DM basis were used for in situ incubations and for collection of rumen fluid. The feed samples were ground through a 2.0-mm screen before the in situ incubations and a 1.0-mm screen before the in vitro gas incubations. In situ nylon bags were introduced into the rumen for determination of k(d) of NDF. Additional kinetic data were produced from isolated NDF and intact samples subjected to in vitro incubations in which gas production was recorded for 72 h. Samples were weighed in the bottles or within filter bags (for fiber and in vitro studies) that were placed in the bottles. The interaction between feed and method was significant (P < 0.01); k(d) of NDF for grass hay tended (P = 0.06) to be less whereas k(d) of NDF for alfalfa, barley grain, canola meal, and dried sugar beet pulp were greater (P < 0.01) when estimated with the in situ method than from gas production recordings. The meta-analysis suggested that in situ derived k(d) of NDF were biased and underestimated in vivo digestibility of NDF. Digestion rates of the intact samples were lower for all feeds, except for the hay, when incubated within the bags compared with dispersed in the medium (P < 0.01). Less OM and NDF were digested for all feeds when incubated within bags than dispersed in the medium (P < 0.01). It is concluded from the in vitro study that microbial activity within the bags is less than in the medium. Significant interactions between method (in situ vs. in vitro) and feed suggest that one or both methods result in biased estimates of digestion kinetics.
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| 9. |
- Krizsan, Sophie Julie, et al.
(författare)
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Predicting feeding value of forage maize hybrids harvested at different maturities and sites
- 2014
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Ingår i: Journal of Animal and Feed Sciences. - : The Kielanowski Institute of Animal Physiology and Nutrition, PAS. - 1230-1388. ; 23, s. 269-278
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate two near-infrared reflectance spectroscopy (NIRS) applications and different laboratory methods for determining indigestible neutral detergent fibre (iNDF) and organic matter digestibility (OMD) of forage maize hybrids harvested at high latitudes. Different in situ and in vitro methods have been used in calibrations of NIRS for routine determinations of forage feed value in the Nordic countries. Swedish and Finnish NIRS calibrations of iNDF generated biased estimates of low precision of iNDF determined in situ. All methods used to predict OMD in forage maize systematically underestimated the observed OMD calculated from the in situ determined value of iNDF. Digestibility was determined with least precision based on the enzymatic in vitro procedure. Values of OMD based on the in vitro incubation in buffered rumen fluid displayed the smallest error among the laboratory methods. The NIRS calibration developed with the forage maize samples of this study, suggested that NIRS has a great potential to predict iNDF and OMD of forage maize accurately and precisely. It was concluded that NIRS predictions of OMD can be a promising tool for evaluating performance of forage maize hybrids at high latitudes if NIRS calibrations of iNDF including forage maize samples are available.
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