Table 2.
Least squares means and 95% confidence intervals of blood metabolites and markers of liver function for low (high efficient; HE) and high (low efficient; LE) residual feed intake (RFI) mid-lactation multiparous dairy cows enrolled in 45-day feed efficiency studies.
| RFI Group 3 | |||
|---|---|---|---|
| Item 1 | HE | LE | p-Value |
| Energy and liver function markers | |||
| BUN, mg/dL | 18.4 [13.8, 22.9] | 18.1 [13.5, 22.6] | 0.72 |
| Lactate, mg/dL | 6.3 [5.3, 7.7] | 7.0 [5.8, 8.8] | 0.44 |
| Albumin, g/dL | 4.4 [3.9, 4.6] | 4.3 [3.9, 4.7] | 0.62 |
| Insulin, µ/L | 0.42 [0.33, 0.51] | 0.48 [0.32, 0.63] | 0.50 |
| AST, U/L | 151.5 [110.6, 192.3] | 142.9 [100.6, 185.1] | 0.55 |
| ALT, U/L | 29.6 [26.3, 33.0] | 32.2 [30.1, 34.3] | 0.18 |
| AST:ALT | 5.1 [3.2, 6.9] | 4.4 [2.8, 6.0] | 0.13 |
| RQUICKI 2 | 0.52 [0.45, 0.60] | 0.53 [0.45, 0.60] | 0.84 |
| Acylcarnitines, µM | |||
| Free carnitine | 5.6 [3.5, 7.6] | 6.2 [4.1, 8.3] | 0.26 |
| C2-aclycarnitine | 2.2 [0.5, 3.9] | 2.3 [1.0, 3.7] | 0.54 |
| C3-aclycarnitine | 0.9 [0.7,1.1] | 1.3 [1.0, 1.6] | 0.01 |
| C4-aclycarnitine | 0.24 [0.21, 0.27] | 0.33 [0.28, 0.38] | 0.01 |
| C5-aclycarnitine | 0.08 [0.02, 0.14] | 0.07 [0.03, 0.12] | 0.70 |
| C16-aclycarnitine | 0.002 [0.001, 0.005] | 0.002 [0.001, 0.005] | 0.86 |
| C18-aclycarnitine | 2.4 [1.2, 6.3] | 2.3 [1.2, 5.9] | 0.88 |
| C18:1-aclycarnitine | 0.24 [0.11, 0.75] | 0.17 [0.09, 0.43] | 0.16 |
| C5-DC-acylcarnitine | 1.0 [0.6, 2.6] | 1.2 [0.6, 3.2] | 0.47 |
| C4-OH-acylcarnitine | 0.23 [0.003, 0.80] | 0.26 [0.01, 0.86] | 0.11 |
1 BUN = blood urea nitrogen; AST = aspartate aminotransferase; and ALT = alanine aminotransferase. 2 Revised quantitative insulin sensitivity check index (Holtenius and Holtenius, 2007) calculated as: RQUICKI = 1/[log (glucose mg/dL) + log (insulin µIU/mL) + log (non-esterified fatty acids mmol/L)]. 3 HE, n = 18; and LE, n = 18.