Comparison of Methods to Measure Methane for Use in Genetic Evaluation of Dairy Cattle
Philip C. Garnsworthy,
Gareth F. Difford,
Matthew J. Bell,
Ali R. Bayat,
Pekka Huhtanen,
Björn Kuhla,
Jan Lassen,
Nico Peiren,
Marcin Pszczola,
Diana. Sorg,
Marleen H.P.W. Visker,
Tianhai Yan
Affiliations
Philip C. Garnsworthy
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
Gareth F. Difford
Department of Molecular Biology and Genetics—Center for Quantitative Genetics and Genomics, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
Matthew J. Bell
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
Ali R. Bayat
Milk Production, Production Systems, Natural Resources Institute Finland (Luke), FI 31600 Jokioinen, Finland
Pekka Huhtanen
Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
Björn Kuhla
Institute of Nutritional Physiology “Oskar Kellner”, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
Jan Lassen
Department of Molecular Biology and Genetics—Center for Quantitative Genetics and Genomics, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
Nico Peiren
Flanders Research Institute for Agriculture, Fisheries and Food, Animal Sciences Unit, Scheldeweg 68, 9090 Melle, Belgium
Marcin Pszczola
Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637 Poznan, Poland
Diana. Sorg
Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Animal Breeding, Theodor-Lieser-Str. 11, 06120 Halle, Germany
Marleen H.P.W. Visker
Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700 AH Wageningen, The Netherlands
Tianhai Yan
Agri-Food and Biosciences Institute, Hillsborough, Co. Down BT26 6DR, UK
Partners in Expert Working Group WG2 of the COST Action METHAGENE have used several methods for measuring methane output by individual dairy cattle under various environmental conditions. Methods included respiration chambers, the sulphur hexafluoride (SF6) tracer technique, breath sampling during milking or feeding, the GreenFeed system, and the laser methane detector. The aim of the current study was to review and compare the suitability of methods for large-scale measurements of methane output by individual animals, which may be combined with other databases for genetic evaluations. Accuracy, precision and correlation between methods were assessed. Accuracy and precision are important, but data from different sources can be weighted or adjusted when combined if they are suitably correlated with the ‘true’ value. All methods showed high correlations with respiration chambers. Comparisons among alternative methods generally had lower correlations than comparisons with respiration chambers, despite higher numbers of animals and in most cases simultaneous repeated measures per cow per method. Lower correlations could be due to increased variability and imprecision of alternative methods, or maybe different aspects of methane emission are captured using different methods. Results confirm that there is sufficient correlation between methods for measurements from all methods to be combined for international genetic studies and provide a much-needed framework for comparing genetic correlations between methods should these become available.