Table 5.

Volatile fatty acid (VFA) at 4, 24, and 48 h after incubation of roughage to concentrate ratios

Items	Roughage to concentrate ratios				SEM	Contrastc
	80:20	60:40	40:60	20:80		L	Q
Total VFA (mM)
4	18.9a	19.2a	23.1b	27.6c	0.42	***	***
24	46.6a	50.3a	56.3b	61.4c	1.08	***	ns
48	68.9a	71.3ab	77.8bc	81.1c	2.36	**	ns
VFA (mM/100 mM)
Acetate
4	65.6	64.5	64.9	65.3	0.90	ns	ns
24	66.2a	66.0a	66.4a	64.4b	0.48	*	ns
48	64.3	63.9	62.5	62.8	0.46	ns	ns
Propionate
4	22.3	22.2	22.6	23.5	1.79	ns	ns
24	22.6	22.3	22.2	22.5	0.38	ns	ns
48	21.9	22.1	22.2	21.5	0.34	ns	ns
Butyrate
4	10.0	9.9	10.0	10.1	1.69	ns	ns
24	10.0	10.0	10.3	10.6	0.32	ns	ns
48	10.3	10.3	10.5	10.4	0.41	ns	ns
Acetate:propionate
4	3.02	2.99	2.90	2.73	0.23	ns	ns
24	2.93	2.96	2.99	2.87	0.05	ns	ns
48	2.94	2.89	2.82	2.93	0.06	ns	ns

^a,bValues within a row with different superscript letters are significantly different (p<0.05).

^cL, linear, Q, quadratic; ns, non-significant.

^*p<0.05,

^**p<0.01,

^***p<0.001.