Effects of a wide range of dietary forage-to-concentrate ratios on nutrient utilization and hepatic transcriptional profiles in limit-fed Holstein heifers

Table 3 Influence of dietary forage levels on liver and plasma metabolites in Holstein heifers

Items^c	Forage levels (% of diet DM)				SEM^d	P-value
Items^c	20	40	60	80	SEM^d	Treatment	Linear	Quadratic	Cubic
Liver
TC, mg/g of liver tissue	1.39^ab	1.40^ab	2.53^a	1.19^b	0.170	0.029	0.710	0.056	0.026
TG, μmol/g of liver tissue	3.67	3.99	6.72	3.83	0.397	0.027	0.369	0.056	0.034
Plasma
Total protein, g/L	71.71	71.32	71.57	71.60	0.961	0.993	0.989	0.831	0.843
Glucose, mmol/L	4.54	4.53	4.40	4.49	0.126	0.856	0.624	0.711	0.549
Lactate Dehydrogenase, U/L	996.43	944.55	934.24	951.20	54.359	0.857	0.557	0.536	0.954
Aspartate Aminotransferase, U/L	68.06	71.18	65.03	73.67	4.084	0.490	0.567	0.510	0.207
ALT, U/L	36.78^b	40.06^b	44.07^ab	53.60^a	2.312	0.007	< 0.001	0.197	0.650
TC, mmol/L	2.46	2.74	2.92	2.81	0.141	0.169	0.070	0.188	0.773
TG, mmol/L	0.37	0.31	0.44	0.39	0.051	0.407	0.451	0.904	0.136
Alkaline Phosphatase, mmol/L	141.94	129.10	139.79	157.86	13.350	0.518	0.343	0.265	0.790
Urea, mmol/L	3.33^a	3.19^a	3.09^ab	2.55^b	0.113	0.001	< 0.001	0.097	0.362
β-hydroxybutyric acid, mmol/L	0.13	0.12	0.11	0.12	0.005	0.204	0.057	0.493	0.520
Total amino acids, mmol/L	3.70	3.91	4.57	3.30	0.473	0.324	0.803	0.140	0.275
Nonesterified Fatty Acid, mmol/L	0.47	0.46	0.45	0.44	0.014	0.531	0.162	0.783	0.820
Total Bilirubin, μmol/L	12.02	11.83	11.22	12.52	0.581	0.486	0.739	0.222	0.380
VLDL-C, mmol/L	0.53	0.75	0.58	0.94	0.060	0.001	0.002	0.259	0.003
LDL-C, mmol/L	0.58	0.58	0.96	0.98	0.085	0.004	0.001	0.893	0.077
HDL-C, mmol/L	1.63	1.71	1.63	1.52	0.094	0.579	0.348	0.326	0.801

(n = 6)
^a–bMeans within a row with different superscripts differ significantly (P < 0.05)
^cALT alanine aminotransferase, TC total cholesterol, TG total triglycerides, VLDL-C very low-density lipoprotein cholesterol, LDL-C low-density lipoprotein cholesterol, HDL-C high-density lipoprotein cholesterol
^dSEM standard error of the mean

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