Table 4.

Production and composition of fermentative gasses produced by in vitro cultures containing ruminal contents from control-fed and crude glycerin-fed steers, when cultures were fed substrates consisting of diets with 0 or 15% crude glycerin (Exp. 1)

Item, mL	Control-fed rumen fluid		Crude glycerin-fed rumen fluid		P-value3
	CON1	15CG2	CON	15CG	Diet	Substrate	D×S
Total gas	107.7	108.3	83.4	88.9	0.16	0.84	0.87
Methane	5.0	4.7	5.9	7.3	0.11	0.61	0.45
Carbon dioxide	29.3	25.9	18.0	21.2	0.24	0.98	0.61

¹CON = Control diet, without crude glycerin.

²15CG = 15% added crude glycerin.

³Diet = Finishing diet fed to donor animals, Substrate = Diet that was included in the in vitro fermentations, D×S = Interaction of diet of the donor animal and substrate fed to the in vitro culture.