Table 7.
The effects of genotype of the capn1_4751 SNP on the tenderness phenotypes, Warner–Bratzler shear force (WBSF) and myofibril fragment length (MFL) of representative purebred South African beef bulls during 3 to 20 days of ageing and on the muscle protease enzyme system during the first 20 h post-mortem.
| capn1_4751 | *CC (n = 53) | CT (n = 63) | TT (n = 50) |
p-Value (Simplified) |
Genotype Effect |
|---|---|---|---|---|---|
| WBSF (d 3) | 5.89 ± 0.16 | 6.17 ± 0.15 | 6.26 ± 0.22 | 0.3758 | − |
| WBSF (d 9) | 4.47 ± 0.14 | 4.94 ± 0.13 | 4.85 ± 0.19 | 0.3035 | − |
| WBSF (d 14) | 3.84 ± 0.12 b | 4.14 ± 0.11 ab | 4.31 ± 0.17 a | 0.0357 | −10.8% |
| WBSF (d 20) | 3.58 ± 0.11 b | 3.88 ± 0.11 ab | 4.07 ± 0.16 a | 0.0226 | −12.0% |
| MFL (d 3) | 32.43 ± 0.79 y | 35.72 ± 0.73 z | 36.17 ± 1.09 z | 0.0790 | −10.4% |
| MFL (d 9) | 24.20 ± 0.52 b | 26.14 ± 0.48 a | 26.69 ± 0.72 a | 0.0474 | −9.3% |
| MFL (d 14) | 22.11 ± 0.49 y | 24.36 ± 0.45 z | 24.07 ± 0.67 z | 0.0762 | −8.1% |
| MFL (d 20) | 20.32 ± 0.40 | 21.90 ± 0.37 | 21.94 ± 0.55 | 0.1056 | − |
| calpastatin (1 h) | 2.02 ± 0.04 | 2.03 ± 0.04 | 2.08 ± 0.06 | 0.1216 | − |
| calpastatin (20 h) | 1.73 ± 0.05 | 1.73 ± 0.05 | 1.74 ± 0.07 | 0.1424 | − |
| calpain-1 (1 h) | 1.54 ± 0.03 a | 1.43 ± 0.03 b | 1.48 ± 0.05 ab | 0.0340 $ | +4.1% |
| calpain-1 (20 h) | 1.14 ± 0.04 | 1.13 ± 0.04 | 1.08 ± 0.05 | 0.1847 | − |
| calpain-2 (1 h) | 1.03 ± 0.01 | 1.00 ± 0.01 | 1.03 ± 0.02 | 0.2252 | − |
| calpain-2 (20 h) | 1.05 ± 0.02 | 1.04 ± 0.01 | 1.03 ± 0.02 | 0.3517 | − |
| calpastatin/calpain-1 (1 h) | 1.35 ± 0.03 | 1.45 ± 0.03 | 1.46 ± 0.04 | 0.3813 | − |
| calpastatin/calpain-1 (20 h) | 1.64 ± 0.06 | 1.69 ± 0.05 | 1.77 ± 0.08 | 0.7056 | − |
| calpastatin/calpains (1 h) | 0.79 ± 0.01 | 0.84 ± 0.01 | 0.84 ± 0.02 | 0.8265 | − |
| calpastatin/calpains (20 h) | 0.79 ± 0.02 | 0.80 ± 0.02 | 0.83 ± 0.02 | 0.3613 | − |
*CC—the genotype that favored tenderness; least squares means (LSM) ± standard errors (SE) that were significantly different within rows or ageing periods (p ≤ 0.05) were indicated with different ascending letter superscripts (a, b), and those that tended to be significantly different (p ≤ 0.10) with different descending letter superscripts (z, y). $ adjusted p-values only tended to be significant; MFL—myofibril fragment length; WBSF—Warner–Bratzler shear force.