Fig. 3

Comparison of gas production parameters for different models. Vf, t0.5, µ0.5 are the average of each category of feedstuff. Means with different letters differ (P < 0.05). EXP0: exponential without lag phase; EXPL: exponential with lag phase; GOM: Gompertz; LOG: logistic; LE0: logistic-exponential without lag phase; LEL: logistic-exponential with lag phase; MIT: Mitscherlich; MM: Michaelis‒Menten; Vf: final asymptotic gas production; t0.5: the time at Vf/2; µ0.5: fractional rate of gas production at Vf/2.