Methane emissions from Swedish sheep production

.......................................................................................................................................................4 SAMMANFATTNING.....................................................................................................................................4 OBJECTIVES......................................................................................................................................................4 INTRODUCTION.............................................................................................................................................5 MATERIALS AND METHODS....................................................................................................................8 Brief descriptions of the farms ....................................................................................................... 10 RESULTS ......................................................................................................................................................... 11 Literature review................................................................................................................................... 11 Methane emissions from sheep................................................................................................. 11 Feeding.................................................................................................................................................. 11 Feeding practices in Sweden ................................................................................................. 12 Ratios concentrates: roughage in the diet....................................................................... 14 Digestibility of feeds .................................................................................................................. 15 Type of roughage......................................................................................................................... 15 Level of feeding ............................................................................................................................ 16 Fat supplementation.................................................................................................................. 16 Methane emissions from sheep on pasture......................................................................... 16 Age differences .................................................................................................................................. 19 Diurnal fluctuations ........................................................................................................................ 21 Eventual differences between sexes ....................................................................................... 22 Breeds and eventual breed differences ................................................................................. 22 Number of lambs per ewe............................................................................................................ 23 Individual differences in the size of emissions .................................................................. 24 Methane measurement techniques ......................................................................................... 25