Table 7.

Effect of the type of forage and vitamin E supplementation on fermentation products and microbial protein synthesis in the Rusitec system.

Forage	Grass		Grass hay		SED1	P-value
Vitamin E1	GRA−	GRA+	HAY−	HAY+		F	V	F × V
FERMENTATION PRODUCTS (mmol/d)
Total VFA	31.2	33.8	35.1	35.5	2.374	0.131	0.383	0.536
Acetate	14.2	15.7	15.7	16.8	1.247	0.182	0.164	0.794
Propionate	8.02	8.93	9.60	9.96	0.801	0.047	0.293	0.631
Butyrate	4.50	4.94	5.51	5.04	0.483	0.139	0.975	0.211
Isobutyrate	0.39	0.41	0.39	0.41	0.036	0.950	0.433	0.947
Valerate	1.28	1.27	1.60	1.42	0.067	<0.001	0.066	0.107
Isovalerate	1.07	1.28	1.13	1.22	0.086	0.958	0.034	0.356
Ammonia N (mg/d)	58.8	58.3	48.8	46.5	3.86	0.003	0.616	0.755
OUTFLOW (mg/d)
DM (g/d)	15.0	15.3	14.4	14.2	0.50	0.046	0.955	0.559
Vitamin E	2.27c	35.3b	0.60c	51.7a	4.44	0.043	<0.001	0.018
NAN	140	152	122	115	6.92	<0.001	0.609	0.084
NANM-N2	39.9b	54.8a	36.9b	28.6b	5.97	0.007	0.456	0.022
Microbial-N	100.5	97.7	84.9	86.3	4.71	0.003	0.840	0.536
N Metabolism (%)
Rumen apparent N degradability	36.5	31.0	41.8	45.1	3.15	0.002	0.630	0.079
Rumen true N degradability	82.0a	75.2b	82.4a	86.4a	2.73	0.015	0.491	0.021
Microbial-N from ammonia	36.0	36.3	45.7	44.8	2.47	<0.001	0.875	0.746
EFFICIENCY OF SYNTHESIS (g/g)
Microbial-N: NAN	0.72ab	0.64b	0.70ab	0.75a	0.033	0.094	0.726	0.024
Microbial-N: N intake	0.45	0.44	0.41	0.41	0.022	0.032	0.862	0.548
Microbial-N: true N degradable	0.55	0.59	0.49	0.48	0.031	0.003	0.622	0.269
Microbial-N: Deg.OM (mg/g)	17.0	14.9	13.6	13.2	0.644	<0.001	0.027	0.104

¹Standard error of the difference for the interaction between the type of forage and the vitamin E supplementation at 50 IU/d (F × V, n = 4). Within a row means without a common superscript differ (P < 0.05).

²NANM-N; non-ammonia non-microbial N calculated by subtracting microbial N from non-ammonia N flow.