Table 5.
Least squares means for the effects of lubabegron1 (LUB) on growth performance traits and carcass characteristics of beef cattle over a 56 d treatment period
| LUB (mg·kg−1 DM) | Difference from control2 | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | CON | 1.5 | 3.5 | 5.5 | SEM | Ptrt3 | PLin4 | PQuad5 | 1.5 mg·kg−1 vs. control | 3.5 mg·kg−1 vs. control | 5.5 mg·kg−1 vs. control |
| Growth performance | |||||||||||
| Initial body weight (BW)6, kg | 567.7 | 569.0 | 569.5 | 567.6 | 2.3 | 0.709 | Not Determined | Not Determined | 1.3 | 1.8 | −0.1 |
| Final BW6,7, kg | 667.4 | 679.0 | 683.1 | 681.7 | 2.7 | <0.001 | <0.001 | <0.001 | 11.6 (1.7)3,x | 15.7 (2.4)3,y | 14.3 (2.1)3,x,y |
| Average daily dry matter intake (DMI)7, kg·hd−1 | 10.1 | 10.3 | 10.4 | 10.3 | 0.25 | 0.025 | 0.013 | 0.060 | 0.2 (2.0)3 | 0.3 (3.0)3 | 0.2 (2.0)3 |
| Average daily gain (ADG)6, kg·hd−1 | 1.68 | 1.87 | 1.94 | 1.92 | 0.05 | <0.001 | <0.001 | <0.001 | 0.19 (11.3)3 | 0.26 (15.5)3 | 0.24 (14.3)3 |
| Gain:feed, ADG:DMI6 | 0.167 | 0.182 | 0.187 | 0.186 | 0.003 | <0.001 | <0.001 | <0.001 | 0.015 (9.0)3 | 0.020 (12.0)3 | 0.019 (11.4)3 |
| Carcass characteristics | |||||||||||
| Hot carcass weight (HCW)7, kg | 408.0 | 419.3 | 423.9 | 425.1 | 1.4 | <0.001 | <0.001 | <0.001 | 11.3 (2.8)3,x | 15.9 (3.9)3,y | 17.1 (4.2)3,y |
| Dressing percentage6 | 61.1 | 61.8 | 62.1 | 62.3 | 0.11 | <0.001 | <0.001 | 0.014 | 0.73,x | 1.03,y | 1.23,z |
| Adjusted fat thickness, cm | 1.54 | 1.53 | 1.48 | 1.48 | 0.06 | 0.038 | <0.007 | 0.761 | -0.01x | −0.063,x,y | −0.063,y |
| Ribeye area, cm2 | 93.7 | 97.0 | 99.1 | 99.4 | 1.7 | <0.001 | <0.001 | <0.001 | 3.3 (3.5) 3,x | 5.4 (5.8) 3,y | 5.7 (6.1) 3,y |
| Marbling score8 | 473 | 460 | 450 | 446 | 4.6 | <0.001 | <0.001 | 0.097 | −13.0 (−2.8)3,x | −23.0 (−4.9)3,y | −27.0 (−5.7)3,y |
| Yield grade9 | 3.21 | 3.14 | 3.02 | 3.01 | 0.15 | <0.001 | <0.001 | 0.193 | −0.07 x | −0.193,y | −0.203,y |
| KPH fat, % | 2.11 | 2.12 | 2.12 | 2.14 | 0.03 | 0.774 | Not Determined | Not Determined | 0.01 | 0.01 | 0.03 |
1Experior, Elanco, Greenfield, IN, USA.
2Control values subtracted from treatment values. Values in parenthesis are percent change from Control.
3Different from Control P ≤ 0.05.
4Significance for linear contrast.
5Significance for quadratic contrast.
6Growth performance and dressing percentage were based on unshrunk initial and final BW.
7Initial animal weight used as a covariate.
8400 = Small0 (low choice); 500 = Modest0 (middle choice); 600 = Moderate0 (high choice). Determined by objective measurement with a camera.
9Yield Grade = 2.50 + (0.98 × adj. fat thickness, cm) + (0.2 × KPH fat, %) + (0.0038 × HCW, kg) – (0.32 × ribeye area, cm2).
x,y,zLeast squares means with different superscripts differ P ≤ 0.05.