Table 1. Effect of ceftiofur crystalline-free acid antibiotic treatment on the abundance of microbial cell functions in dairy cow feces ^a .

	Treatment
Functional Category	Antibiotic b	Control	SEM c	P ≤
Amino Acids & Derivatives	9.72	9.65	0.11	0.72
Carbohydrates	16.87	16.78	0.20	0.75
Cell Division & Cell Cycle	1.56	1.60	0.008	0.06
Cell Wall & Capsule	3.74	3.71	0.11	0.87
Clustering-based Subsystems	14.50	14.80	0.03	0.01
Cofactors, Vitamins, Prosthetic Groups, Pigments	4.45	4.48	0.09	0.89
DNA Metabolism	5.16	5.25	0.03	0.12
Dormancy & Sporulation	0.43	0.46	0.01	0.19
Fatty Acids, Lipids, & Isoprenoids	2.01	2.03	0.07	0.84
Iron Acquisition & Metabolism	0.60	0.56	0.03	0.54
Membrane Transport	1.78	1.78	0.03	0.97
Metabolism of Aromatic Compounds	0.44	0.47	0.006	0.06
Miscellaneous	6.25	6.40	0.06	0.19
Motility & Chemotaxis	0.25	0.24	0.003	0.13
Nitrogen Metabolism	0.49	0.50	0.007	0.61
Nucleosides & Nucleotides	3.72	3.50	0.07	0.12
Phages, Prophages, Transposable Elements, Plasmids	3.07	2.34	0.24	0.15
Phosphorus Metabolism	0.51	0.50	0.02	0.74
Photosynthesis	0.02	0.02	0.0006	0.92
Potassium Metabolism	0.11	0.11	0.007	0.72
Protein Metabolism	11.16	11.32	0.13	0.48
RNA Metabolism	6.29	6.45	0.07	0.19
Regulation & Cell Signaling	0.97	0.96	0.01	0.68
Respiration	1.83	1.95	0.06	0.27
Secondary Metabolism	0.20	0.23	0.007	0.07
Stress Response	1.60	1.53	0.02	0.08
Sulfur Metabolism	0.55	1.74	0.03	0.72
Virulence, Disease, & Defense	1.82	1.74	0.03	0.22

Functional sequences expressed as a % of total sample sequences assigned function

^an = 3 subcutaneous antibiotic injection, 1.5 mL ceftiofur crystalline free acid sterile suspension (150 mg ceftiofur activity) per 45.4 kg body weight

^bn = 3

^cStandard error for LSM