Methane gas is known for its negative environmental impact. To reduce negative methane gas released from dairy cattle, genes responsible for its production should be known and identified. A study with an aim of identifying the microbial genes responsible for methane gas release was undertaken. Samples of cattle’s stool on-farms (Lushoto and Rungwe districts of Tanzania) and a station-based (Kanyariri of Kenya) smallholding dairy cattle were collected. On-farm dairy cattle (36) were sampled for their fecal matter while six (6) station-based dairy cattle were sampled for both fecal and rumen fluid. Samples were processed and subsequently analyzed at ILRI, using next generation sequencing. Functional genes associated with methane metabolism were identified from Kyoto Encyclopedia for Genes and Genomes (KEGG) database and Kegg Automatic Annotation Server (KAAS) version 2.1. Enzyme Commissions and methanogenesis genes identified were 9 and 7, respectively. The genes were Formylmethanofuran dehydrogenases, Methylene Tetrahydromethanopterin (H4MPT) dehydrogenase, Methylene–H4MPT reductase, Tetrahydromethanopterin S- methyl transferase, Methyl coenzyme M reductase, Methyl viologen reducing hydrogenase and Heterodisulfide reductase. When targeting to lower methane release from dairy cattle, caution should be exercised in order not to hinder other necessary metabolic processes in the targeted pathways that are also critical for life.

Keywords: Greenhouse, pathways, methanogenesis, on-farm, Station-based