Table 5.

Digestibility of tocopherol in rumen, intestine, and total-tract (mg/g).¹

Item	Diets2				SEM	P-values3
	Oat	D	T	DT		Dec	Toa	Dec × Toa
Total α-tocopherol
Rumen	91	25	37	−9	47.2	0.22	0.33	0.82
Small intestine	340	365	404	437	108.6	0.78	0.53	0.97
Feed-ileum	310	363	415	409	102.9	0.82	0.49	0.79
Hindgut	20	−60	−377	−1,033	506.5	0.47	0.20	0.57
Total tract	426	369	317	234	42.3	0.10	0.02	0.72
Natural α-tocopherol4
Rumen	−227	−276	−296	−357	63.9	0.31	0.18	0.91
Small intestine	394	388	443	466	110.2	0.94	0.56	0.90
Feed-ileum	481	514	636	591	144.7	0.97	0.45	0.80
Hindgut	24	−64	−403	−1,010	493.1	0.49	0.19	0.60
Total tract	310	213	153	21	57.8	0.06	0.01	0.73
Synthetic α-tocopherol5
Rumen	314	235	270	227	39.7	0.17	0.53	0.66
Small intestine	268	339	353	402	109.5	0.57	0.48	0.92
Feed-ileum	189	263	268	284	108.1	0.58	0.53	0.72
Hindgut	3	−53	−353	−1,066	528.9	0.47	0.22	0.53
Total tract	506	482	435	379	35.0	0.26	0.04	0.64
RRR-α-tocopherol6
Rumen	−231	−301	−292	−355	61.5	0.23	0.28	0.94
Small intestine	375	385	433	459	107.0	0.86	0.54	0.94
Feed-ileum	458	517	611	580	138.4	0.92	0.47	0.76
Hindgut	29	−56	−418	−1,040	499.7	0.48	0.18	0.59
Total tract	280	196	119	−2	58.0	0.10	0.02	0.73
Synthetic 2R-α-tocopherol7
Rumen	372	307	354	309	34.7	0.13	0.82	0.76
Small intestine	289	331	354	404	111.6	0.66	0.51	0.97
Feed-ileum	182	234	235	258	98.5	0.61	0.60	0.84
Hindgut	654	17	−419	−1,052	529.2	0.51	0.16	0.57
Total tract	584	578	475	447	35.1	0.65	0.01	0.76
2S-α-tocopherol8
Rumen	418	359	349	318	43.2	0.34	0.25	0.75
Small intestine	231	322	341	390	128.0	0.59	0.49	0.87
Feed-ileum	156	211	239	237	79.0	0.75	0.51	0.73
Hindgut	−61	−160	−222	−1,006	518.3	0.40	0.35	0.51
Total tract	550	506	538	458	35.6	0.05	0.27	0.49
α-Tocotrienol9
Rumen	563	514	256	385	142.9	0.63	0.04	0.32
Small intestine	412	551	60	−93	682.8	0.99	0.25	0.72
Feed-ileum	203	270	272	−102	431.2	0.55	0.42	0.43
Hindgut	1,000	1,000	1,000	1,000	–	–	–	–
Total tract	1,000	1,000	1,000	1,000	–	–	–	–
γ-Tocopherol10
Rumen	261	226	216	174	54.9	0.76	0.94	0.66
Small intestine	309	334	334	311	53.5	0.98	0.11	0.35
Feed-ileum	228	269	271	258	54.5	0.80	0.78	0.64
Hindgut	−271	−316	−396	−278	100.8	0.72	0.77	0.51
Total tract	345	295	329	268	58.4	0.15	0.54	0.89

¹Digestibility values in rumen, small intestine, hindgut, and total tract are reported in milligram of digested per g of intake, duodenal flow, ileal flow, and intake, respectively (Supplementary S1). Negative values represent the ruminal or hindgut formation.

²Oat = whole grain oat; D = decorticated oat; T = toasted oat; DT = decorticated and toasted oat.

³Dec = effect of decortication; Toa = effect of toasting; Dec × Toa = interaction between toasting and decortication.

⁴Natural α-tocopherol originates from feedstuffs.

⁵Synthetic α-tocopherol originates from vitamin supplement.

⁶RRR-α-tocopherol (2R-(4′R, 8′R)-5,7,8-trimethyltocol) originates from feedstuffs and supplement.

⁷Synthetic 2R-α-tocopherol is summation of RRS (2R-(4′R, 8′S)-5,7,8-trimethyltocol), RSR (2R-(4′S, 8′R)-5,7,8-trimethyltocol), and RSS-α-tocopherol (2R-(4′S, 8′S)-5,7,8-trimethyltocol).

⁸2S-α-tocopherol is summation of SRR (2S-(4′R, 8′R)-5,7,8-trimethyltocol), SSR (2S-(4′S, 8′R)-5,7,8-trimethyltocol), SRS (2S-(4′R, 8′S)-5,7,8-trimethyltocol), and SSS-α-tocopherol (2S-(4′S, 8′S)-5,7,8-trimethyltocol).

⁹α-Tocotrienol (2R-(4′R, 8′R)-5,7,8-trimethyltocotrienol).

¹⁰γ-Tocopherol (2R-(4′R, 8′R)-,7,8-dimethyltocol).