Table 4.
Descriptive statistics for hematological, stress responsiveness, and immune competence traits measured on 59 Angus steers and heifers1 bred to vary in genetic merit for postweaning RFI at the end of their 10-wk feedlot RFI test while still on the feedlot test ration ad libitum, and their correlations with midparent RFIP-EBV and with feedlot-test DMI and RFI
| Correlations | ||||||||
|---|---|---|---|---|---|---|---|---|
| Trait | Units | Mean | SD | Min. | Max. | RFIp-EBVmp2 | DMI | RFIf |
| Hematology | ||||||||
| White blood cells | 106/mL | 9.67 | 1.78 | 5.78 | 14.59 | −0.51*** | −0.29* | −0.42*** |
| Lymphocytes | 106/mL | 4.84 | 0.98 | 3.25 | 7.67 | −0.43*** | −0.34** | −0.54*** |
| Neutrophils | 106/mL | 3.73 | 1.29 | 1.74 | 8.47 | −0.31* | −0.12 | −0.11 |
| Monocytes | 106/mL | 0.76 | 0.19 | 0.35 | 1.24 | −0.20 | −0.14 | −0.19 |
| Eosinophils | 106/mL | 0.21 | 0.21 | 0.01 | 1.30 | −0.21 | 0.02 | −0.19 |
| Basophils | 106/mL | 0.14 | 0.05 | 0.06 | 0.30 | −0.14 | −0.18 | −0.15 |
| Red blood cells | 109/mL | 7.37 | 0.63 | 6.12 | 8.56 | −0.06 | 0.00 | 0.03 |
| Hemoglobin | g/dL | 13.6 | 1.1 | 11.4 | 15.9 | −0.06 | 0.07 | 0.12 |
| Hematocrit | % | 42.0 | 3.0 | 35.0 | 48.0 | −0.03 | 0.11 | 0.16 |
| MCV | fL | 57.2 | 4.2 | 46.2 | 66.3 | −0.06 | 0.12 | 0.14 |
| MCH | pg | 18.5 | 1.3 | 15.3 | 21.1 | 0.02 | 0.09 | 0.11 |
| MCHC | g/dL | 32.3 | 0.9 | 29.6 | 34.1 | −0.09 | −0.09 | −0.08 |
| Platelets | 106/mL | 549 | 146 | 212 | 851 | −0.09 | −0.41** | −0.38** |
| %Lymphocyte | % | 50.5 | 7.9 | 33.3 | 69.5 | 0.07 | −0.12 | −0.18 |
| %Neutrophil | % | 38.0 | 7.9 | 22.1 | 58.1 | −0.10 | 0.09 | 0.18 |
| Stress responsiveness | ||||||||
| ∆HAPT | mg/mL | 0.08 | 0.39 | −0.93 | 2.11 | 0.08 | 0.10 | 0.14 |
| Immune competence | ||||||||
| AIR11 | OD units | 1.11 | 0.30 | 0.45 | 1.91 | −0.04 | −0.07 | −0.15 |
| AIR32 | OD units | 0.71 | 0.25 | 0.10 | 1.28 | 0.12 | −0.02 | −0.02 |
| CIR-ctrl | mm | 0.63 | 0.72 | −0.93 | 2.27 | −0.01 | −0.20 | −0.04 |
| CIR test | mm | 8.04 | 3.06 | 4.30 | 23.1 | 0.25† | 0.32* | 0.28* |
1Comprising 29 steers and 30 heifers.
2Midparent EBV for postweaning RFI.
RFI = residual feed intake; RFIp = %RFI measured postweaning; MCV = mean corpuscular volume; MCH = mean corpuscular hemoglobin; MCHC = mean corpuscular hemoglobin concentration; ∆HAPT = change in serum haptoglobin levels from day 0 to day 4 after the RFI test; AIR11 = antibody immune response reported as change in antibody level values at day 11 relative to day 0 after the RFI test; AIR32 = AIR reported as change in antibody level values at day 32 relative to day 0 after the RFI test; CIR ctrl = cellular immune response to saline control injection; CIR test = CIR relative to control in response to vaccine injection; RFIf = RFI measured in the feedlot.
*P < 0.05; **P < 0.01; ***P < 0.001.