Table 2. Phenotypic differences between sire groups (low RFI sire–high RFI sire) compared with expected progeny difference based on bull breeding values.
Differences between sire progeny groups for growth, intake, feed efficiency, feeding behavior, methane production, and carcass traits are provided, including trait, trait mean, mean difference between sire groups, P-value for that difference (P<0.05 bolded), and expected progeny difference based on sire breeding values where available.
| Trait Type | Trait | Period | Mean (SE) | Sire Group Difference | P-value | Expected Progeny Difference |
|---|---|---|---|---|---|---|
| Growth, | MMW, kg0.75 | Growing | 74.5 (1.1) | 0.8 | 7.3 E-01 | |
| Intake, & | Finishing | 100.4 (0.9) | 3.3 | 4.0 E-02 | ||
| Feed | ADG, kg/d | Growing | 1.71 (0.05) | 0.00 | 9.8 E-01 | 0.00 |
| Efficiency | Finishing | 1.40 (0.06) | 0.22 | 8.0 E-02 | ||
| DMI, kg DM/d | Growing | 9.55 (0.25) | -0.48 | 3.4 E-01 | -0.18 | |
| Finishing | 8.52 (0.20) | 0.01 | 9.8 E-01 | |||
| Feed conversion | Growing | 5.63 (0.17) | -0.28 | 4.1 E-01 | ||
| ratio (DMI/ADG) | Finishing | 6.21 (0.23) | -1.08 | 1.0 E-02 | ||
| RFI, kg DM/d | Growing | 0.00 (0.19) | -0.62 | 9.0 E-02 | -0.16 | |
| Finishing | 0.00 (0.15) | -0.57 | 5.0 E-02 | |||
| Feeding | Bunk Visits, visits/d | 57.7 (2.9) | -12.9 | 2.0 E-02 | ||
| Behavior | Bunk Visit Duration, min/visit | 1.87 (0.13) | 0.60 | 1.0 E-02 | ||
| (Growing Period) | Feeding Duration, min/d | 96.7 (3.1) | 7.04 | 2.6 E-01 | ||
| Methane Production | Controlled feed amount and interval, g CH4/d | 165.3 (13.1) | 6.6 | 8.1 E-01 | ||
| (Finishing Period) | Ad lib feeding, g CH4/d | 161.8 (9.5) | 8.7 | 6.6 E-01 | ||
| Carcass | Final weight, kg | 533.9 (6.1) | 28.8 | 1.0 E-02 | MW 33.6 | |
| Hot carcass weight, kg | 323.4 (4.1) | 12.6 | 1.1 E-01 | 10.5 | ||
| Rib-eye area, cm2 | 80.2 (1.9) | 6.8 | 7.0 E-02 | 5.7 | ||
| Backfat thickness, mm | 12.9 (0.4) | -0.5 | 5.4 E-01 | -0.5 | ||
| Yield grade | 3.0 (0.1) | -0.3 | 2.6 E-01 | |||
| Marbling score | 6.8 (0.3) | 0.0 | 1.0 E+00 | 0.0 | ||
| Carcass specific gravity | 1.08 (0.002) | 0.0045 | 3.0 E-02 | |||
| Heart weight, kg | 2.01 (0.10) | 0.25 | 2.0 E-01 | |||
| Liver weight, kg | 6.00 (0.17) | -0.03 | 9.2 E-01 | |||
| Kidney weight, kg | 1.00 (0.03) | -0.03 | 6.4 E-01 | |||