Fig. 3

Effects of melatonin supplementation on rumen methane (CH₄) production and VFA in cows with intact rumen. A Rumen fluid melatonin concentrations (N = 8 for control, N = 8 for melatonin groups). B CH₄ production of melatonin-treated group compared with before and after treatment (N = 5 for control, N = 5 for melatonin groups). C CH₄ production of melatonin treated compared with control group (N = 5 for control, N = 5 for melatonin groups). D VFA content. Data were expressed as mean ± SEM (N = 10 for control, N = 10 for melatonin groups). Ns, no significant difference, * < 0.05, ** < 0.01, *** < 0.001, **** < 0.0001