Meta‐Analysis of Methane Mitigation Strategies: Improved Predictions of Mitigation Potentials and Production Implications

The aim of this study was to use meta-analysis to identify the enteric methane (CH4) mitigation strategy that reduced CH4 emission without lowering production. To this end, a database initially developed was updated, compiling data from 61 publications (233 experiments) for various observations in dairy cattle on effects of hydrogen sink (H-sink), ionophore, lipid and concentrate feeds inclusion on enteric CH4 produc-tion, milk production and milk composition from dair cattle. There was no significant effect (P>0.05) of H-sink and ionophore feeds inclusion on CHy 4 production while supplementation of lipid and concentrate considerably suppressed CH4 production (P<0.05). CH4 production per kg milk produced was not de-pressed with H-sink treatment (P<0.05). Lipids lightly increased CH4 production per kg milk from 26.19 g kg−1 for control to 29.12 g kg−1 for treatment (P>0.05), while concentrate and ionophore feeds inclusion decreased CH4 production per kg milk with no significant effect (P>0.05). There was a significant effect of concentrate on milk protein and milk yield, which increased from 23.27 kg d−1 for control to 26.52 kg d−1 for concentrate treated diet (P<0.05). Milk yield and milk protein was not significantly affected with H-sink, ionophore and lipid feeds inclusion (P>0.05). This meta-analysis demonstrates that lipid and concen-trate feeds inclusion reduced CH4 emissions from dairy cattle without lowering their pr