Table 4.
The effects of genotype of the capn2_780 SNP on the tenderness phenotype, Warner–Bratzler shear force (WBSF) of representative purebred South African beef bulls during three to 20 days of ageing and on the muscle protease enzyme system during the first 20 h post-mortem.
| capn2_780 | *AA (n = 112) | AG (n = 39) | # GG (n = 15) |
p-Value (Simplified) |
Genotype Effect |
|---|---|---|---|---|---|
| WBSF (d 3) | 6.05 ± 0.11 | 6.54 ± 0.20 | − | 0.3279 | − |
| WBSF (d 9) | 4.77 ± 0.09 | 4.83 ± 0.17 | − | 0.1467 | − |
| WBSF (d 14) | 4.10 ± 0.08 | 4.30 ± 0.15 | − | 0.2274 | − |
| WBSF (d 20) | 3.84 ± 0.08 | 3.93 ± 0.14 | − | 0.3831 | − |
| calpastatin (1 h) | 2.06 ± 0.03 | 1.87 ± 0.05 | − | 0.9969 | − |
| calpastatin (20 h) | 1.75 ± 0.03 | 1.48 ± 0.06 | − | 0.7869 | − |
| calpain-1 (1 h) | 1.45 ± 0.02 | 1.35 ± 0.04 | − | 0.3737 | − |
| calpain-1 (20 h) | 1.10 ± 0.03 | 0.99 ± 0.05 | − | 0.3225 | − |
| calpain-2 (1 h) | 1.00 ± 0.01 | 0.95 ± 0.02 | − | 0.9139 | − |
| calpain-2 (20 h) | 1.03 ± 0.01 | 0.96 ± 0.02 | − | 0.6730 | − |
| calpastatin/calpain-1 (1 h) | 1.47 ± 0.02 | 1.42 ± 0.04 | − | 0.7586 | − |
| calpastatin/calpain-1 (20 h) | 1.74 ± 0.04 | 1.62 ± 0.07 | − | 0.9579 | − |
| calpastatin/calpains(1 h) | 0.85 ± 0.01 | 0.82 ± 0.02 | − | 0.7954 | − |
| calpastatin/calpains (20 h) | 0.83 ± 0.01 | 0.77 ± 0.02 | − | 0.7862 | − |
*AA—the genotype that favored tenderness; least squares means (LSM) ± standard errors (SE) were not significantly different (p > 0.10). # Tough homozygotes were not available for comparison; WBSF—Warner–Bratzler shear force.