Bacillus subtilis and Macleaya cordata extract regulate the rumen microbiota associated with enteric methane emission in dairy cows

Table 1 Comparison of physiological parameters and rumen fermentation characteristics among CON, BS, and MCE cows (n = 60)

Item	Dietary treatment			SEM	P value
Item	CON	BS	MCE	SEM	P value
DMI, kg/day	22.78^b	25.96^a	25.35^a	0.210	0.040
FPCM, kg/day	30.33^b	33.35^a	32.62^a	0.271	< 0.001
CH₄/FPCM, g/kg	13.22^a	12.40^b	12.45^b	0.150	0.038
Rumen pH	6.22	6.04	6.18	0.040	0.163
Total VFA, mmol/L	109.94	112.18	108.58	1.881	0.743
Acetate, %	59.79^a	57.13^b	58.72^ab	0.360	0.008
Propionate, %	25.43^b	29.28^a	26.81^b	0.442	0.001
Butyrate, %	11.84^a	10.89^b	11.85^a	0.182	0.045
Isobutyrate, %	0.67	0.48	0.59	0.044	0.217
Valerate, %	1.37	1.34	1.22	0.030	0.074
Isovalerate, %	0.89	0.89	0.81	0.035	0.561
Ammonia N, mg/dL	11.6^ab	10.99^b	12.34^a	0.229	0.049
Acetate/propionate	2.41^a	1.98^b	2.21^a	0.051	0.002

Data were analyzed using the one-way ANOVA procedure (n = 20 per group). ^a,bMeans bearing different superscripts in the same row differ significantly (P value < 0.05)
DMI dry matter intake, FPCM fat- and protein-corrected milk (kg/d) = milk (kg) × [0.337 + 0.116 × fat (%) + 0.06 × protein (%)] [27]. CH₄, methane. SEM, standard error of the mean, CON control diet, BS control diet plus Bacillus subtilis, MCE control diet plus Macleaya cordata extract

ISSN: 2049-2618