Table 6.

Discriminant metabolites with down‐regulated in the rumen fluid of high production dairy cows and their corresponding metabolic pathways

Metabolic pathway	Metabolite	VIP	fold_change	q value
Purine metabolism	Hypoxanthine	2.845	2.343	0.012
	Guanosine;	2.867	2.974	0.018
Riboflavin metabolism	Riboflavin	1.884	1.482	0.021
Indole diterpene alkaloid biosynthesis	Terpendole E;	1.922	1.498	0.031
Glucosinolate biosynthesis	9‐Methylthiononanaldoxime;	2.687	2.983	0.019
Brassinosteroid biosynthesis	22alpha‐Hydroxy‐campest‐4‐en‐3‐one	3.840	14.100	0.017
Terpenoid backbone biosynthesis	Isopentenyl phosphate;	3.386	6.262	0.017
	All‐trans‐Hexaprenyl diphosphate;	2.653	2.184	0.014
Neuroactive ligand‐receptor interaction	N‐Arachidonyl dopamine	2.831	2.515	0.017
Biosynthesis of type II polyketide products	15‐Demethoxy‐epsilon‐rhodomycin;	2.682	2.429	0.044
	Epsilon‐Rhodomycin T;	2.658	3.818	0.025
	Aclacinomycin T	2.073	1.633	0.046
Carotenoid biosynthesis	4,4’‐Diapolycopenedial;	2.980	3.655	0.017
Biosynthesis of alkaloids derived from terpenoid and polyketide	Jervine;	3.338	6.084	0.012
	Thiobinupharidine;	2.890	3.084	0.016
Pyrimidine metabolism	Cytosine;	3.018	3.160	0.019
Arachidonic acid metabolism	Prostaglandin E2	3.037	4.148	0.025
Porphyrin and chlorophyll metabolism	Protoporphyrin	2.098	1.879	0.048
Fatty acid degradation	L‐Palmitoylcarnitine;	3.103	4.497	0.007
Steroid degradation	Androsta‐1,4‐diene‐3,17‐dione;	4.446	5.758	0.013
Puromycin biosynthesis	N‐Acetylpuromycin;	2.512	2.196	0.016
Steroid hormone biosynthesis	Urocortisol	3.370	4.597	0.016
Naphthalene degradation	cis‐1,2‐Dihydroxy‐1,2‐dihydro‐8‐carboxynaphthalene;	2.155	1.631	0.036
Biosynthesis of antibiotics	Antibiotic JI‐20B	3.551	9.685	0.029
	Epsilon‐Rhodomycin T;	2.658	3.818	0.025
	N‐Acetylpuromycin;	2.512	2.196	0.016
	Nebramycin factor 4;	2.598	2.060	0.031
	Aclacinomycin T	2.073	1.633	0.046
Steroid biosynthesis	5‐Dehydroavenasterol;	3.654	11.265	0.023
Ubiquinone and other terpenoid‐quinone biosynthesis	All‐trans‐Hexaprenyl diphosphate;	2.653	2.184	0.014