The effect of ensiled paulownia leaves in a high-forage diet on ruminal fermentation, methane production, fatty acid composition, and milk production performance of dairy cows

Table 2 The effect of paulownia leaves silage (PLS) on in vitro ruminal fermentation and methane production (n = 4) (Exp.1)

Parameters^a	CON	PLS, g/kg DM^b			SEM	Contrast^c
Parameters^a	CON	20	40	60	SEM	L	Q	C
Rumen fermentation
Redox potential, mV	-313	-314	-316	-319	1.27	0.22	0.77	0.87
pH	6.28	6.52	6.62	6.71	0.02	< 0.01	< 0.01	0.06
NH_3, mmol/L	9.09	9.30	12.5	12.8	0.25	< 0.01	0.89	< 0.01
Total VFA, mmol/L	63.5	64.9	66.5	69.5	0.48	< 0.01	0.19	0.68
VFA, mol/100 mol
Acetate (A)	60.5	57.8	57.4	55.6	0.37	< 0.01	0.38	0.10
Propionate (P)	16.9	18.3	18.8	19.7	0.21	< 0.01	0.27	0.25
Isobutyrate	0.85	0.96	1.04	1.11	0.02	< 0.01	0.08	0.63
Butyrate	13.1	14.0	14.3	14.6	0.12	< 0.01	0.22	0.44
Isovalerate	2.49	2.44	2.41	2.40	0.04	0.29	0.69	0.96
Valerate	6.05	6.44	6.44	6.59	0.08	< 0.01	0.28	0.29
A/P ratio	3.56	3.19	3.04	2.84	0.05	< 0.01	0.18	0.31
Degradability, g/kg DM
DM	538	540	562	564	6.07	0.18	0.99	0.52
OM	570	573	593	595	5.70	0.18	0.99	0.52
CP	569	574	578	582	2.74	0.13	0.97	0.93
NDF	437	420	443	440	6.67	0.71	0.64	0.31
Total gas and methane production
TGP, mL/d	3722	3881	3958	4151	25.7	< 0.01	0.71	0.31
CH_4, mmol/L	9.45	8.10	6.08	5.94	0.21	< 0.01	0.03	0.04
CH_4, mmol/g DMD	1.58	1.29	0.94	0.92	0.04	0.02	0.03	0.17
CH_4, mmol/g NDFD	3.57	3.05	2.26	2.04	0.10	0.26	0.39	0.15

^aVFA volatile fatty acid, DM dry matter, Om, organic matter, CP crude protein, NDF neutral detergent fiber, TGP total gas production, DMD dry matter degradability NDFD neutral detergent fiber degradability
^bCON control diet, PLS paulownia leaves silage diet, PLS was used at 20, 40, and 60 g/kg DM of diet replacing alfalfa silage
^cL linear response, Q quadratic response, C cubic response. The results are considered to be significantly different at P ≤ 0.05

ISSN: 2049-1891