Table 3.

Effects of crude protein level and sanitary conditions on ammonia N and volatile fatty acids (VFA) concentrations in jejunal and colonic digesta in weaned pigs¹

	Clean conditions			Unclean conditions			SEM	P-values2
Item	HCP	LCP 1	LCP 2	HCP	LCP 1	LCP 2		San	CP	AA	San × CP
Ammonia N, mg/L
Jejunum	50.0	24.8	22.4	64.4	33.5	31.0	5.9	0.034	0.001	0.676	0.583
Colon	63.8	61.6	94.6	75.4	85.0	122.8	27.7	0.348	0.366	0.196	0.762
Jejunal VFA, mmol/L
Acetic acid	4.60	2.71	3.21	3.83	5.43	3.95	0.675	0.113	0.513	0.467	0.041
Propionic acid	0.14	0.16	0.20	0.22	0.16	0.38	0.054	0.032	0.241	0.010	0.894
Butyric acid	0.36	0.31	0.33	0.26	0.27	0.27	0.030	0.006	0.437	0.669	0.298
Isobutyric acid	0.72	0.58	0.49	0.83	0.78	0.93	0.073	0.001	0.190	0.672	0.077
Isovaleric acid	0.02	0.01	0.03	0.12	0.10	0.14	0.023	0.001	0.869	0.226	0.858
Valeric acid	0.07	0.06	0.05	0.01	0.02	0.02	0.009	0.001	0.676	0.625	0.305
Total BCFA3	0.80	0.65	0.57	1.02	0.87	1.09	0.087	0.001	0.110	0.401	0.335
Total VFA	5.08	2.89	3.75	4.29	5.85	4.61	0.723	0.097	0.521	0.792	0.041
Colonic VFA, mmol/L
Acetic acid	60.0	50.2	57.3	56.7	52.1	53.3	2.91	0.450	0.043	0.170	0.649
Propionic acid	28.3	31.6	30.1	29.3	31.8	35.9	2.30	0.217	0.072	0.577	0.590
Butyric acid	21.6	18.6	29.0	18.1	21.4	22.2	4.32	0.483	0.427	0.211	0.844
Isobutyric acid	0.94	0.89	1.56	0.70	0.67	0.72	0.160	0.002	0.291	0.031	0.287
Isovaleric acid	1.14	1.13	1.95	0.79	0.82	0.92	0.209	0.002	0.191	0.038	0.376
Valeric acid	6.10	7.83	9.65	4.80	8.15	8.63	1.662	0.627	0.036	0.496	0.741
Total BCFA	8.25	9.85	13.06	6.29	9.64	10.28	1.756	0.256	0.029	0.285	0.881
Total VFA	109	99	107	104	105	112	5.8	0.719	0.917	0.242	0.331

¹HCP, high crude protein; LCP 1, low crude protein supplemented with nine indispensable crystalline amino acids except for Arg; LCP 2, low crude protein supplemented with only six indispensable crystalline amino acids (Lys, Met, Thr, Trp, Val, and Ile).

²San, main effect of sanitation; CP, main effect of crude protein levels (HCP vs. LCP 1 and LCP 2); AA, main effect of crystalline amino acids supplementation patterns (LCP 1 vs. LCP 2); San × CP, interactive effect of sanitation and crude protein levels (HCP vs. LCP 1 and LCP 2).

³Branched chain fatty acids = isobutyrate + isovalerate + valerate.