Table 4. Changes in the in vitro ruminal pH values and volatile fatty acid concentrations by the thickness of corn flakes using the pressurized steam chamber

Item	Time (h)	Treatments¹⁾			SEM
Item	Time (h)	T1	T2	T3	SEM
pH	3	6.68^NS	6.69^NS	6.68^NS	0.01
	6	6.34^NS	6.35^NS	6.41^NS	0.02
	12	5.20^b	5.20^b	5.41^a	0.08
	24	4.47^NS	4.51^NS	4.58^NS	0.04
Acetate (mmol/L)	3	29.81^NS	27.76^NS	28.60^NS	1.65
	6	39.22^NS	37.69^NS	35.34^NS	1.36
	12	52.14^NS	49.44^NS	52.20^NS	2.38
	24	82.24^NS	80.15^NS	79.67^NS	3.56
Propionate (mmol/L)	3	7.76^NS	8.55^NS	8.12^NS	0.51
	6	17.07^a	14.40^b	13.91^b	0.84
	12	26.84^NS	26.13^NS	24.78^NS	1.37
	24	61.12^ab	63.43^a	59.49^b	2.16
Butyrate (mmol/L)	3	7.63^NS	7.37^NS	8.11^NS	0.62
	6	11.80^NS	12.02^NS	12.07^NS	0.59
	12	16.58^NS	18.10^NS	16.74^NS	0.83
	24	30.17^NS	30.41^NS	29.22^NS	1.85
Total-VFA (mmol/L)	3	45.21^NS	43.68^NS	44.83^NS	1.74
	6	68.10^a	64.10^ab	61.32^b	2.03
	12	95.56^NS	93.66^NS	93.72^NS	3.65
	24	173.53^NS	174.09^NS	168.48^NS	5.70

Treatments : T1 < 2.5 mm, T2 = 2.5–3.0 mm, and T3 > 3.0 mm.
Means without same superscripts within a row are significantly different (p < 0.05).
SEM, standard error of the mean; NS, not significant; T-VFA, total volatile fatty acid.