Table 5.
Meta-regression estimates (univariable analyses) for the effects of length of time that beef was aged before evaluation, length of time that cattle were fed, use of multiple HGP implants (yes or no), treatment comparisons using TBA (yes or no), breed of cattle, sex of cattle, and electrical stimulation of the carcass on WBSF responses
| Variable | SMD | SE | 95% CI | P-value | R 2 | I 2, % | τ2 |
|---|---|---|---|---|---|---|---|
| Aging of the beef, d (KH) | −0.005 | 0.003 | −0.010 to 0.001 | 0.105 | −0.55 | 46.7 | 0.043 |
| Aging of the beef, d (robust) | −0.009 | 0.008 | −0.029 to 0.011 | 0.315 | 0.001 | ||
| Length of feeding, d (KH) | 0.001 | 0.0006 | −0.0002 to 0.002 | 0.125 | −5.06 | 39.9 | 0.035 |
| Length of feeding, d (robust) | 0.001 | 0.0026 | −0.010 to 0.013 | 0.705 | 0.001 | ||
| Multiple implants, % of studies (KH) | 0.196 | 0.051 | 0.095 to 0.296 | 0.001 | 18.1 | 46.9 | 0.036 |
| Multiple implants, % of studies (robust) | 0.487 | 0.164 | 0.083 to 0.892 | 0.026 | 0.001 | ||
| TBA, % of studies (KH) | −0.100 | 0.077 | −0.252 to 0.052 | 0.196 | −3.17 | 47.1 | 0.045 |
| TBA, % of studies (robust) | 0.241 | 0.232 | −0.290 to 0.772 | 0.327 | 0.001 | ||
| Breeda (reference British, British cross, European, and Holstein) | |||||||
| Brahman and Brahman crosses (KH) | −0.017 | 0.064 | −0.144 to 0.110 | 0.789 | 4.39 | 42.7 | 0.042 |
| Crossbred (undescribed; KH) | 0.189 | 0.087 | 0.018 to 0.360 | 0.031 | |||
| Not stated (KH) | 0.423 | 0.217 | −0.006 to 0.853 | 0.053 | |||
| Sexa (reference steers) | |||||||
| Bull (KH) | 0.289 | 0.186 | −0.077 to 0.656 | 0.121 | 9.21 | 44.3 | 0.040 |
| Heifer (KH) | −0.084 | 0.055 | −0.193 to 0.024 | 0.127 | |||
| Mixed (KH) | 0.082 | 0.115 | −0.145 to 0.308 | 0.477 | |||
| Stimulation (reference not stimulated) | |||||||
| Stimulated (KH) | 0.059 | 0.090 | −0.119 to 0.238 | 0.512 | 4.08 | 47.9 | 0.042 |
| Not stated (KH) | 0.197 | 0.094 | 0.012 to 0.383 | 0.037 | |||
The estimates based on Knapp–Hartung methods (KH) provide a SMD, SE, and 95% CI of the SMD, significance (P-value), model fit (R2), and measures of heterogeneity I2 and τ2. Estimates based on robust regression methods (robust) at the treatment level provide a SMD, SE, and 95% CI of the SMD, P-value, and τ2. There were 177 treatment comparisons and 28 experiments.
aThe distribution of data leads to small degrees of freedom for sex and breed, resulting in unreliable P-values for the robust regression.