Table 5.
Effect of treatment and stage of storage on methane production and gas kinetics of wet brewer’s grain silage fermented in vitro for 24 h1,2
Item3 | Treatment | Mean | SEM | P-value | ||||||
---|---|---|---|---|---|---|---|---|---|---|
CON | INO | NaL1 | NaL2 | PRP | TRT | STG | TRT × STG | |||
Mf, mL/g incubated DM | 7.81 | <0.001 | <0.001 | 0.058 | ||||||
Fresh | - | - | - | - | - | 215A | ||||
Ensiled | - | - | - | - | - | 181B | ||||
AES | - | - | - | - | - | 155C | ||||
Mean | 184b | 182bc | 169c | 183b | 200a | |||||
Kf, %/h | 0.847 | 0.006 | <0.001 | 0.09 | ||||||
Fresh | - | - | - | - | - | 14.6A | ||||
Ensiled | - | - | - | - | - | 12.6B | ||||
AES | - | - | - | - | - | 9.81C | ||||
Mean | 13.4a | 13.0ab | 11.0c | 11.8bc | 12.6ab | |||||
Lag, h | 0.228 | 0.400 | 0.007 | 0.007 | ||||||
Fresh | 0.15B | 0.274 | 0.522 | 0.498 | 0.448B | |||||
Ensiled | 0.148B | 0.250 | 0.910 | 0.230 | 0.174B | |||||
AES | 1.39Aa | 0.644bc | 0.430c | 0.230c | 1.15Aab | |||||
Methane production, mg | 0.270 | 0.058 | <0.001 | 0.775 | ||||||
Fresh | - | - | - | - | - | 3.16A | ||||
Ensiled | - | - | - | - | - | 2.43B | ||||
AES | - | - | - | - | - | 2.00C | ||||
Methane concentration, mM | 0.069 | 0.087 | 0.033 | 0.696 | ||||||
Fresh | - | - | - | - | - | 0.944A | ||||
Ensiled | - | - | - | - | - | 0.850B | ||||
AES | - | - | - | - | - | 0.833B | ||||
Methane yield, mmol/g fermented OM | 0.026 | 0.072 | 0.025 | 0.855 | ||||||
Fresh | - | - | - | - | - | 0.273A | ||||
Ensiled | - | - | - | - | - | 0.234B | ||||
AES | - | - | - | - | - | 0.233B |
CON, control (no additive); INO, inoculant delivering L. lactis and L. buchneri 150,000 cfu per g of fresh WBG each; NaL1, sodium lignosulfonate applied at a rate of 10 g/kg fresh basis; NaL2, sodium lignosulfonate applied at a rate of 20 g/kg, fresh basis; PRP, propionic acid (Alfa Aesar; 99%) applied at a rate of 5 g/kg, fresh basis. Fresh, fresh WBG prior to ensiling; ensiled, ensiled WBG after 60 d of storage; AES, aerobically exposed WBG silage 10 d after opening.
Whenever the interaction TRT × STG was not significant (P > 0.05), the means of significant main effects (P ≤ 0.05) are presented instead.
Mf, asymptotic maximal gas production in a 24 h in vitro fermentation. Kf, rate of gas production.
Means with different uppercase superscripts within a column are significantly different (P ≤ 0.05).
Means with different lowercase superscripts within a row are significantly different (P ≤ 0.05).