Can feeding dried browse leaves to sheep reduce methane emissions and improve weight gain?

Abstract

It is important to evaluate whether a specific browse leaf will be able to reduce methane emissions as well as improve weight gain before recommending it to farmers. Therefore, the objective of this study was to determine performance, methane emission and amplification of methanogens and protozoa of sheep fed four different dried browse leaves. Sixteen forest-type ram lambs of 14.38±0.51 kg average weight were used. The animals were fed four dried browse leaves [Albizzia lebbek (AL), Gliricidia sepium (GS), Moringa oleifera (MO) and Millettia thonningii (MT)] for six weeks. Genomic DNAs were extracted from methanogen and protozoa strains obtained from rumen fluid and sheep faeces using Quick-DNA™ Fecal/Soil Microbe Miniprep Kit. Sheep fed AL, MO and MT responded by gaining weight but those fed GS lost weight with time. All four browse leaves fed produced low methane and the trend of methane emission was relatively stable. Detecting methanogens and protozoa in the rumen fluid and faeces of sheep is an indication that the browse leaves were able to inhibit the activities of methanogens and protozoa in the rumen and eliminated them through faeces. Therefore, AL, MO and MT can improve weight gain and reduce methane emission while GS can minimise methane emission but cannot improve weight gain. This study highlights the contribution of natural resources to climate-smart approaches in sheep production and reduction of enteric methane production hence minimising the effects of climate change.