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Predicting methane production in dairy cows

Ramin, Mohammad (2013). Predicting methane production in dairy cows. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2013:72
ISBN 978-91-576-7882-9
eISBN 978-91-576-7883-6
[Doctoral thesis]

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Methane is a potent greenhouse gas, to which enteric fermentation from ruminants contributes significantly. Reliable and accurate predictions of methane (CH₄) production from dairy cows would be of interest to develop mitigation strategies and for national inventories. Thus, the overall aim of this thesis was to predict CH₄ production in dairy cows by modelling approaches.

Predicted in vivo CH₄ production decreased with increased sample size in the gas in vitro system. Molar proportion of acetate decreased at the expense of propionate. Digestibility also decreased with increased sample size. Predicted CH₄ production based on stoichiometric equations of volatile fatty acids was in good agreement with observed values of CH₄ production from the gas in vitro system.

Dry matter intake per kilogram of body weight, organic matter digestibility and dietary concentrations of neutral detergent fibre, non-fibre carbohydrates and ether extract were the variables of the best fit model predicting CH₄ energy as a proportion of gross energy (prediction error 4.65% of the observed mean). The non-linear models developed proved to be more applicable over a wider range of intake for predicting total CH₄ production than linear models. Adjusting the exponents for dietary concentration of fat, proportion of non-fibre carbohydrates in total carbohydrates and organic matter digestibility improved the model.

The sub-model predicting CH₄ production in the Karoline model was revised. Modifications were made to equations predicting digesta passage kinetics, microbial cell synthesis, digestion in the hind-gut and utilisation of hydrogen. The sensitivity analysis suggested that accurate values for digestion kinetic variables are required for accurate and acceptable predictions of CH₄ production with mechanistic models. The Karoline model was evaluated against published data (n=184 diets) reporting CH₄ production from in vivo trials. There was a good relationship between observed and predicted values of CH₄ production, with a small root mean square error of prediction (10.1% and 6.1% of the observed mean for fixed and mixed models, respectively). The mean bias was small (<2%) but statistically significant, and there was no slope bias. Most of the error was due to random bias (96.4%), whereas the contributions of mean and slope bias were small (3.4 and 0.2%, respectively).

Authors/Creators:Ramin, Mohammad
Title:Predicting methane production in dairy cows
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :21 November 2013
Number of Pages:84
I.M. Ramin and P. Huhtanen. (2012). Development of an in vitro method for determination of methane production kinetics using a fully automated in vitro gas system - A modelling approach. Animal Feed Science and Technology 174, 190-200.
II.M. Ramin and P. Huhtanen. (2013). Development of equations for predicting methane emissions from ruminants. Journal of Dairy Science 96, 2476-2493.
III.M. Ramin and P. Huhtanen. (2013). Development of non-linear models for predicting enteric methane production. Acta Agriculturae Scandinavica Section A-Animal Science 62 (4), 254-258.
IV.P. Huhtanen, M. Ramin and P. Udén. (2013). Nordic dairy cow model Karoline in predicting methane emissions: 1. Model description and sensitivity analysis (submitted).
V.M. Ramin and P. Huhtanen. (2013). Nordic dairy cow model Karoline in predicting methane emissions: 2. Model evaluation (submitted).
Place of Publication:Umeå
Publisher:Dept. of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-7882-9
ISBN for electronic version:978-91-576-7883-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L02 Animal feeding
L Animal production > L51 Animal physiology - Nutrition
T Pollution > T01 Pollution
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 402 Animal and Dairy Science > Animal and Dairy Science.
Agrovoc terms:dairy cows, methane emission, rumination, rumen microorganisms, digestion, feed intake, dry matter content, digestibility, in vitro experimentation, models
Keywords:Dairy cow, Methane production, Modelling, In vitro gas production, Rumen model
Permanent URL:
ID Code:10910
Department:(NL, NJ) > Dept. of Agricultural Research for Northern Sweden
(VH) > Dept. of Agricultural Research for Northern Sweden
Deposited By: Mr Mohammad Ramin
Deposited On:22 Nov 2013 13:02
Metadata Last Modified:14 Dec 2014 00:23

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