Table 3. Effect of glycerin inclusion on total and individual VFA concentrations in dual-flow continuous culture system.

Item 1	Glycerin, %			SEM	P-value
	0	15	30		Linear	Quadratic
Total VFA, mM	113	123	125	1.81	< 0.01	0.12
VFA, mM
Acetate	66.5	59.9	48.8	2.17	< 0.01	0.42
Propionate	25.3	43.5	58.6	3.55	< 0.01	0.47
Butyrate	17.7	16.4	13.3	0.82	0.01	0.52
Valerate	1.33	1.18	1.21	0.07	0.45	0.53
Iso-Butyrate	0.42	0.24	0.22	0.03	< 0.01	0.03
Iso-Valerate	1.61	1.19	0.69	0.11	< 0.01	0.74
BCVFA, mM	2.98	2.62	2.03	0.31	< 0.01	0.07
Acetate: propionate	2.65	1.41	0.84	0.19	< 0.01	0.22

¹VFA = volatile fatty acids; BCVFA = Branched-chain VFA.