Table 3.

Effect of microencapsulated organic acids and pure botanicals on kinetics of pH and fermentation metabolites in a dual-flow continuous-culture system collected at 0, 1, 2, 4, 6, and 8 h postmorning feeding

Parameter	Level of inclusion1				SEM	P-value2
	0	30	60	90		Lin	Quad
pH	6.11	6.16	6.14	6.12	0.04	0.92	0.16
NH3, mM/dL	12.3	11.6	13.0	12.2	0.84	0.56	0.76
Lactate, mM/dL	0.06	0.07	0.08	0.09	0.01	0.18	0.99
d-lactate, mM/dL	0.04	0.04	0.05	0.05	0.01	0.18	0.91
d-lactate, %	62.8	59.3	61.2	60.6	1.26	0.24	0.12
l-lactate, mM/dL	0.02	0.03	0.03	0.03	0.01	0.21	0.86
l-lactate, %	37.2	40.7	38.8	39.4	1.26	0.24	0.12
SCFA, mM/L
Acetate	45.6	44.6	45.3	46.2	0.82	0.37	0.12
Propionate	18.7	19.2	18.6	18.8	0.61	0.95	0.67
Butyrate	16.5	15.8	16.7	15.7	1.31	0.57	0.79
Isobutyrate	0.82	0.77	0.86	0.81	0.04	0.50	0.68
Isovaleric	2.47	2.26	2.66	2.46	0.21	0.60	1.00
Valeric	2.34	2.13	2.27	2.21	0.08	0.41	0.29
Caproic	2.96	2.88	2.65	2.88	0.23	0.51	0.35
Total	89.3	87.7	89.2	88.9	2.05	0.90	0.50
A:P3	2.45	2.33	2.43	2.47	0.08	0.59	0.27
(A + B):P2	3.34	3.15	3.33	3.32	0.14	0.77	0.37
Molar proportion, %
Acetate	56.5	55.4	56.1	57.4	1.00	0.33	0.12
Propionate	23.2	23.9	23.1	23.4	0.76	0.95	0.67
Butyrate	20.5	19.6	20.8	19.5	1.63	0.57	0.79
Isobutyrate	1.01	0.96	1.07	1.00	0.05	0.50	0.68
Isovaleric	3.06	2.81	3.31	3.05	0.27	0.61	0.99
Valeric	2.90	2.65	2.82	2.74	0.10	0.41	0.29
Caproic	3.68	3.58	3.28	3.56	0.28	0.48	0.36

¹Levels of inclusion ranging from 0 to 90 g/25 kg of total mixed ration.

²Contrast: linear and quadratic, there was no cubic effect, thus P-values are not presented. Fixed effect of time for all variables was significant (P < 0.001), the interaction between treatment and time was not significant for all analyzed variables (P > 0.05), thus P-values will not be shown.

³A:P is the molar ratio of acetate and propionate; (A + B):P is the ratio of acetate and butyrate divided by propionate.