. 2019 Jun 12;9(6):343. doi: 10.3390/ani9060343

Table 3.

Gas production kinetics and fermentation parameters of tomato pomace samples taken from two processing plants at weekly intervals during the tomato harvesting campaign and samples.

Item	Sampling Time (Weeks)						Average	SEM ¹	p-Value
Item	1	2	3	4	5	6	Average	SEM ¹	p-Value
Gas production parameters ²
PGP (mL/g dry matter (DM))	199 ^a	201 ^ab	226 ^b	211 ^ab	210 ^ab	187 ^a	206	5.9	0.001
c (%/h)	7.28	7.17	6.97	7.04	7.17	6.88	7.09	0.181	0.316
lag (h)	2.33	2.63	2.33	2.50	2.42	2.48	2.45	0.130	0.064
AGPR (mL/h)	8.51 ^ab	8.32 ^ab	9.39 ^b	8.81 ^b	8.73 ^b	7.48 ^a	8.54	0.262	0.001
DMED (g/kg)	324 ^c	305 ^bc	332 ^c	313 ^b	320 ^c	276 ^a	312	7.3	<0.001
Fermentation parameters ³
pH	6.81 ^ab	6.80 ^ab	6.76 ^b	6.75 ^b	6.79 ^ab	6.83 ^a	6.79	0.015	0.004
Total volatile fatty acids (VFA; mmol/g DM)	6.21 ^ab	6.34 ^b	6.52 ^b	6.37 ^b	6.41 ^b	5.78 ^a	6.27	0.25	0.004
Molar proportions (mol/100 mol)
Acetate	66.8 ^ab	65.9 ^a	66.3 ^ab	66.3 ^ab	67.0 ^b	66.8 ^ab	66.5	0.23	0.007
Propionate	23.0 ^ab	23.5 ^ab	23.6 ^b	23.5 ^ab	23.0 ^ab	22.7 ^a	23.2	0.21	0.014
Butyrate	7.17	7.41	7.44	7.36	7.23	7.37	7.33	0.068	0.043
Minor VFA	2.98 ^ab	3.14 ^b	2.64 ^a	2.82 ^ab	2.78 ^ab	3.10 ^b	2.91	0.105	0.011
Acetate/propionate (mol/mol)	2.91 ^ab	2.80 ^a	2.81 ^ab	2.83 ^ab	2.93 ^ab	2.95 ^b	2.87	0.035	0.009
NH₃ (mg/L)	173	158	155	156	159	155	159	8.2	0.608
CH₄ (mL/g DM)	65.2 ^ab	63.8 ^b	75.0 ^b	76.3 ^a	65.0 ^ab	61.8 ^a	67.9	4.02	0.060
CH₄/VFA (mL/mmol)	10.1	9.33	10.3	10.6	9.91	10.6	10.1	0.346	0.112

^ab Within each parameter, mean values with different superscripts differ (p < 0.05). ¹ SEM: Standard error of the mean. ² PGP: Asymptotic gas production (mL/g DM); c: Fractional rate of gas production (%/h); lag: Time before starting gas production; AGPR: Average gas production rate; DMED: Dry matter effective degradability calculated for a rumen particulate outflow of 4%/h. ³ Minor VFA: Calculated as the sum of isobutyrate, isovalerate and valerate.