Table 4.

Effects of isoflavones and fescue seed type on rumen VFA concentrations in beef steers*

VFA concentration, mmol × L−1	Isoflavones†				SEM	P-value
	0		943
	Fescue seed type‡
	E+	E−	E+	E−		Seed	Treatment	Seed × treatment
Formate	0.34	0.75	0.62	1.11	0.22	0.21	0.08	0.86
Acetate	25.4	24.4	24.5	24.6	2.92	0.87	0.91	0.84
Propionate	15.0	14.5	16.0	15.2	1.82	0.75	0.67	0.93
A:P||	1.76	1.73	1.57	1.63	0.10	0.92	0.21	0.69
Butyrate	5.33	4.72	4.33	4.44	0.60	0.67	0.29	0.55
IVMB$	1.14	0.98	0.87	0.99	0.23	0.86	0.43	0.39
Valerate	0.06	0.16	0.07	0.44	0.13	0.13	0.29	0.32

*Data reported as LSMeans (n = 9/treatment group).

^†Isoflavone treatment administered daily at 0 mg × steer⁻¹ × d⁻¹ (control) or 943 mg × steer⁻¹ × d⁻¹ (isoflavones).

^‡Endophyte-infected (E+) tall fescue seed (0.011 mg ergot alkaloids × kg BW⁻¹ × d⁻¹) or endophyte-free (E−) tall fescue seed (0 mg ergot alkaloids × kg BW⁻¹ × d⁻¹) mixed in total ration, which was fed ad libitum.

^||Ratio of acetate:propionate.

^$Isovalerate and methylbutyrate.