Table 3. Progressive CH₄ yield (L g⁻¹ volatile solids fed) in batch digesters fed manure from steers supplemented with or without (control) GOS, L-cysteine or monensin.

Day	Treatment
	Control	GOS	L-cysteine	Monensin	SEM	p-value
10	0.187a	0.207a	0.214a	0.061b	0.016	0.001
20	0.230a	0.251a	0.259a	0.091b	0.023	0.010
30	0.252a	0.274a	0.281a	0.145b	0.029	0.034
40	0.266	0.287	0.294	0.174	0.037	0.156
50	0.275	0.295	0.302	0.185	0.039	0.197

^a,bMeans within a row with different superscripts differ by the corresponding p-value.

GOS, galacto-oligosaccharides.