## 3 Results  
### In Vitro Gas and Methane Production  
Fractions \"a\" and \"b\" were different between treatments (\(p<0.05\)), being higher for the control treatment (T1) in relation to T2, T3, and T4 (Table 4). The Kd value was affected by the treatments (\(p<0.05\)).  
Lower Kd value for T2 (4.0 mL\({}^{-1}\) h), T3 (6.0 mL\({}^{-1}\) h), and T4 (4.5 mL\({}^{-1}\) h) was observed, and the highest Kd was obtained with the control treatment (8.0 mL\({}^{-1}\) h) (\(p<0.05\)). Despite the nutrients supply by LLL leaves and PP in T2, T3, and P4, the potential gas production gas (PGP) and relative gas production (RGP) values were lower than the control treatment where alfalfa hay was a main source of forage (\(p<0.05\)). Differences were observed among treatments in the methane (CH\({}_{4}\)) and carbon dioxide CO\({}_{2}\)) productions (\(p<0.05\)). Treatment with LLL (T2) showed a reduction of 25.5% in methane production (\(p<0.05\)) when compared to control treatment (T1), whereas carbon dioxide production showed an increase of 28.6% with T2 when compared to control treatment (T1) (\(p<0.05\)). Moreover, there were differences between T1 and T2 in the CO\({}_{2}\):CH\({}_{4}\) ratio (\(p<0.05\)).  
\begin{table}
\begin{tabular}{l c c c c c} \hline  & \multicolumn{4}{c}{**Treatments**} & **SEM** & \(p<\) **Value** \\ \cline{2-6}  & **T1** & **T2** & **T3** & **T4** & \\ \hline a (mL 200 mg\({}^{-1}\) DM) & 16.1 \({}^{\mathrm{a}}\) & 7.1 \({}^{\mathrm{d}}\) & 12.3 \({}^{\mathrm{b}}\) & 9.4 \({}^{\mathrm{c}}\) & 1.8 & 0.001 \\ b (mL 200 mg\({}^{-1}\) DM); & 102.0 \({}^{\mathrm{a}}\) & 85.7 \({}^{\mathrm{d}}\) & 98.3 \({}^{\mathrm{b}}\) & 92.1 \({}^{\mathrm{c}}\) & 2.3 & 0.01 \\ PGP (mL 200 mg\({}^{-1}\) DM) & 118.1 \({}^{\mathrm{a}}\) & 92.8 \({}^{\mathrm{c}}\) & 110.6 \({}^{\mathrm{b}}\) & 101.5 \({}^{\mathrm{b}}\) & 1.1 & 0.05 \\ RGP (mL 200 mg\({}^{-1}\) DM) & 110.1 \({}^{\mathrm{a}}\) & 85.8 \({}^{\mathrm{d}}\) & 101.6 \({}^{\mathrm{b}}\) & 93.5 \({}^{\mathrm{c}}\) & 1.7 & 0.003 \\ Kd (mL\({}^{-1}\) h) & 8.0 \({}^{\mathrm{a}}\) & 4.0 \({}^{\mathrm{d}}\) & 6.0 \({}^{\mathrm{b}}\) & 4.5 \({}^{\mathrm{c}}\) & 0.01 & 0.01 \\ L (h); & 2.5 & 3.3 & 3.1 & 3.1 & 0.33 & 0.120 \\ CH\({}_{4}\) (mL g\({}^{-1}\) DM); & 13.7 \({}^{\mathrm{b}}\) & 10.2 \({}^{\mathrm{d}}\) & 15.8 \({}^{\mathrm{a}}\) & 12.8 \({}^{\mathrm{c}}\) & 3.3 & 0.01 \\ CO\({}_{2}\) (mL g\({}^{-1}\) DM). & 74.8 \({}^{\mathrm{d}}\) & 96.2 \({}^{\mathrm{a}}\) & 87.5 \({}^{\mathrm{c}}\) & 91.1 \({}^{\mathrm{b}}\) & 1.2 & 0.001 \\ CO\({}_{2}\):CH\({}_{4}\):ratio & 5.4 \({}^{\mathrm{c}}\) & 9.4 \({}^{\mathrm{a}}\) & 5.6 \({}^{\mathrm{c}}\) & 7.1 \({}^{\mathrm{b}}\) & 0.12 & 0.001 \\ \hline \end{tabular} \({}^{\mathrm{a}}\)Red Means within the same row with various superscripts are significantly different (\(p<0.05\)). a = Gas production from quickly soluble fraction; b = Gas production from insoluble fraction; PGP = Potential gas production; RGP = Relative gas production; Kd = Gas production rate; L = Discrete lag time prior to gas production; CH\({}_{4}\) = Methane; CO\({}_{2}\) = Carbon dioxide; SEM = Standard error of mean.  
\end{table}
Table 4: In vitro gas parameters and methane production of experimental treatments.  
The CO\({}_{2}\):CH\({}_{4}\) ratio showed an increase of 74.0% with T2 when compared to the control treatment (T1) (\(p<0.05\)).