Table 4.
Least squares means1 by line2 and generation for reproductive, growth, and compositional traits3 in response to selection for age at puberty
| Generation | |||||
|---|---|---|---|---|---|
| Trait | 0 | 1 | 2 | 3 | 4 |
| AGEPUB, d | |||||
| YOUNG | 199 ± 1.6 | 176 ± 2.3 | 176 ± 2.6 | 168 ± 1.9 | 163 ± 1.9 |
| OLD | 197 ± 2.6 | 200 ± 2.9 | 206 ± 3.2 | 183 ± 3.2 | |
| P-value | <0.01 | <0.01 | <0.01 | <0.01 | |
| PUB | |||||
| YOUNG | 0.6 ± 0.03 | 0.68 ± 0.03 | 0.50 ± 0.04 | 0.76 ± 0.03 | 0.87 ± 0.02 |
| OLD | 0.69 ± 0.04 | 0.43 ± 0.04 | 0.72 ± 0.04 | 0.64 ± 0.04 | |
| P-value | 0.86 | 0.19 | 0.44 | <0.01 | |
| PUBWT, kg | |||||
| YOUNG | 113±1.1 | 112 ± 1.4 | 110 ± 1.6 | 110 ± 1.2 | 102 ± 1.2 |
| OLD | 115 ± 1.9 | 114 ± 2.2 | 113 ± 2.5 | 114 ± 2.1 | |
| P-value | 0.27 | 0.12 | 0.26 | <0.01 | |
| LEN1, d | |||||
| YOUNG | 1.69 ± 0.04 | 1.63 ± 0.06 | 1.67 ± 0.07 | 1.55 ± 0.05 | 1.70 ± 0.05 |
| OLD | 1.47 ± 0.08 | 1.44 ± 0.09 | 1.67 ± 0.10 | 1.46 ± 0.08 | |
| P-value | 0.10 | 0.04 | 0.03 | <0.01 | |
| LEN2, d | |||||
| YOUNG | 1.82 ± 0.07 | 1.87 ± 0.07 | 1.97 ± 0.08 | 1.92 ± 0.06 | 1.99 ± 0.05 |
| OLD | 1.93 ± 0.09 | 1.95 ± 0.11 | 1.73 ± 0.12 | 1.55 ± 0.11 | |
| P-value | 0.60 | 0.87 | 0.16 | <0.01 | |
| VW1, cm | |||||
| YOUNG | 38.5 ± 0.31 | 38.7 ± 0.42 | 38.0 ± 0.47 | 38.2 ± 0.35 | 38.0 ± 0.34 |
| OLD | 40.3 ± 0.56 | 38.6 ± 0.64 | 39.4 ± 0.75 | 37.3 ± 0.60 | |
| P-value | 0.02 | 0.45 | 0.14 | 0.28 | |
| VW2, cm | |||||
| YOUNG | 38.3 ± 0.48 | 39.9 ± 0.49 | 39.4 ± 0.54 | 39.9 ± 0.39 | 38.7 ± 0.36 |
| OLD | 40.9 ± 0.62 | 40.1 ± 0.73 | 39.6 ± 0.87 | 38.1 ± 0.76 | |
| P-value | 0.20 | 0.43 | 0.72 | 0.53 | |
| BWT, kg | |||||
| YOUNG | 1.03 ± 0.007 | 1.15 ± 0.011 | 1.11 ± 0.010 | 1.08 ± 0.009 | 1.09 ± 0.010 |
| OLD | 1.13 ± 0.013 | 1.10 ± 0.012 | 0.97 ± 0.016 | 0.99 ± 0.014 | |
| P-value | 0.22 | 0.29 | <0.01 | <0.01 | |
| WWT, kg | |||||
| YOUNG | 5.5 ± 0.038 | 5.60 ± 0.051 | 5.54 ± 0.055 | 5.94 ± 0.046 | 5.39 ± 0.045 |
| OLD | 5.48 ± 0.059 | 5.42 ± 0.060 | 5.51 ± 0.069 | 5.06 ± 0.062 | |
| P-value | 0.12 | 0.07 | <0.01 | <0.01 | |
| LEA, cm2 | |||||
| YOUNG | 42.2 ± 0.46 | 43.7 ± 0.48 | 40.1 ± 0.51 | 40.4 ± 0.48 | 40.6 ± 0.48 |
| OLD | 45.0 ± 0.55 | 41.2 ± 0.55 | 41.4 ± 0.56 | 41.2 ± 0.55 | |
| P-value | <0.01 | 0.56 | 0.05 | 0.23 | |
| BF, cm | |||||
| YOUNG | 1.74 ± 0.042 | 1.75 ± 0.044 | 1.66 ± 0.046 | 1.57 ± 0.044 | 1.70 ± 0.045 |
| OLD | 1.70 ± 0.049 | 1.74 ± 0.048 | 1.62 ± 0.052 | 1.59 ± 0.049 | |
| P-value | 0.20 | 0.08 | 0.24 | <0.01 | |
| WT178, kg | |||||
| YOUNG | 116 ± 1.3 | 115 ± 1.4 | 112 ± 1.4 | 123 ± 1.4 | 119 ± 1.4 |
| OLD | 112 ± 1.5 | 108 ± 1.5 | 119 ± 1.6 | 118 ± 1.5 | |
| P-value | 0.05 | <0.01 | <0.01 | 0.75 |
1Model included generation, line, generation × line interaction and covariate effects.
2YOUNG = young age at puberty line; OLD = old age at puberty line.
3AGEPUB = age at puberty; PUBWT = weight at puberty; LEN1 = length of estrus at puberty; LEN2 = length of estrus at second estrus; VW1 = vulva width at puberty; VW2 = vulva width at second estrus; PUB = probability of reaching puberty; BWT = birth weight; WWT = weaning weight; LEA = loin muscle area; BF = backfat depth, WT178 = weight at 178 d.