Effects of body condition on the insulin resistance, lipid metabolism and oxidative stress of lactating dairy cows

Table 2 Serum energy metabolism, lipid and lipoprotein parameters in cows with different body condition score (BCS)

Item	BCS¹			SEM	P-value
Item	Low	Medium	High	SEM	P-value
Energy metabolism parameters²
Glucose, mmol/L	3.20	3.22	3.27	0.07	0.72
Insulin, mIU/L	19.7^b	20.5^b	24.1^a	1.01	< 0.01
Glucagon, pg/mL	103	111	104	5.9	0.58
NEFA, μmol/L	119^ab	116^b	134^a	5.53	0.06
BHBA, mmol/L	0.56	0.62	0.57	0.03	0.38
RQUICKI	0.47^a	0.47^a	0.44^b	0.01	< 0.01
Lipid and lipoprotein parameters³
Triacylglycerol, μmol/L	32.2^b	34.3^b	50.1^a	5.59	0.06
Cholesterol, mmol/L	6.57	6.46	6.45	0.20	0.90
VLDL, mmol/L	1.80^ab	1.97^a	1.53^b	0.11	0.03
HDL-C, mmol/L	0.43	0.47	0.46	0.02	0.33
apo A-I, mg/L	294^a	280^a	242^b	12.9	0.02
apo B, mg/L	174^a	176^a	155^b	5.1	0.01

^a-b Means within same row with different superscripts differ (P < 0.05)
¹Low: BCS ≤ 2.75 (n = 12); Medium: 3.0 ≤ BCS ≤ 3.5 (n = 15); BCS ≥ 3.75 (n = 15)
²NEFA non-esterified fatty acid; BHBA β-hydroxybutyric acid; RQUICKI revised quantitative insulin sensitivity check index, calculated using the following equation (Leiva et al., 2014): RQUICKI 1/ [log glucose (mg/dL) + log insulin (μIU/mL) + log NEFA (mmol/L)]
³VLDL very low-density lipoprotein; HDL-C high-density lipoprotein cholesterol; apo A-I apolipoprotein A-I; apo B apolipoprotein B