Table 3.

Ex situ methanogenic and fermentative potential of total rumen and cecal contents from lambs receiving wheat- or corn-based diets^a

Parameter	Diet				SEM	P valueb
	Wheat		Corn
	Rumen	Cecum	Rumen	Cecum		D	FC
Gas production at 6 h of incubation
Total (μmol/h)	288.53	272.69	343.61	309.36	26.703	0.101	NS
Methane (μmol/h)	36.64	6.89	33.30	6.93	3.379	NS	<0.01
Methane (%)c	11.18	4.09	9.68	3.16	0.0001	NS	<0.01
Gas production at 24 h of incubation
Total (μmol/h)	146.44	154.30	188.25	164.54	12.155	<0.05	NS
Methane (μmol/h)	28.03	7.43	26.46	6.39	2.71	NS	<0.01
Methane (%)c	14.86	6.77	13.63	5.54	0.673	NS	<0.01
Hydrogen recovery (%)	73.45	56.72	77.71	47.85	4.510	NS	<0.01
VFA production at 24 h of incubation
Total (mM)	110.84	91.15	115.83	88.49	6.697	NS	<0.01
Acetate (%)d	61.10	64.00	61.00	61.00	1.928	NS	NS
Propionate (%)d	20.75	21.75	23.00	25.33	2.119	NS	NS
Butyrate (%)d	11.50	9.56	10.50	10.00	1.486	NS	NS
Acetate/propionate ratio	3.03	3.43	2.66	2.49	0.543	NS	NS
Minor VFA (%)d,e	6.34	4.89	5.50	4.00	0.518	NS	<0.05
pH	5.89	6.03	5.56	5.79	0.138	NS	NS

^aValues represent the means of the results of 12 observations.

^bD, diet; FC, fermentative compartment. The D × FC interaction was never significant (P > 0.05). NS, not significant.

^cμmol of CH₄ per μmol of total gas produced.

^d% mM of individual VFA per mM of total VFA produced.

^eMinor VFA are valerate, isovalerate, isobutyrate, and caproate.