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 production, milk production and milk composition from dairy cattle. there was no significant effect (p>0.05) of h-sink and ionophore feeds inclusion on ch4 production while supplementation of lipid and concentrate considerably suppressed ch4 production (p<0.05). ch4 production per kg milk produced was not depressed 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 concentrate feeds inclusion reduced ch4 emissions from dairy cattle without lowering their production.