Metagenomics reveals differences in microbial composition and metabolic functions in the rumen of dairy cows with different residual feed intake

Table 1 Fermentation variables and methane production in the rumen of dairy cows with high and low residual feed intake (RFI)

Items	High RFI	Low RFI	SEM	P value
pH	6.40	6.46	0.06	0.57
Volatile fatty acid, mM
Total	105	96.7	3.25	0.08
Acetate	66.3	59.4	2.78	0.10
Propionate	23.7	23.5	0.82	0.88
Butyrate	11.7	10.2	0.60	0.10
Isobutyrate	0.76	0.86	0.04	0.12
Valerate	1.52	1.32	0.08	0.08
Isovalerate	1.27	1.45	0.07	0.09
Molar proportion, mM/100 mM
Acetate	62.8	61.6	1.15	0.47
Propionate	22.7	24.0	0.53	0.09
Butyrate	11.0	10.5	0.28	0.30
Isobutyrate	0.74	0.90	0.05	0.05
Valerate	1.44	1.38	0.06	0.43
Isovalerate	1.23	1.50	0.06	< 0.01
Acetate: propionate	2.90	2.63	0.19	0.30
Methane^a, g/d	533	506	8.50	0.04

^aMethane was predicted by the following equation: CH₄ (g/d) = [3.23 (± 1.12) + 0.81 (± 0.086) × DMI (kg/d)] × 18.03 [36], where DMI is the dry matter intake

ISSN: 2524-4671