Table 3.
Age at first egg (AFE)1, maturation interval (MI)1, percentage of hens that did not commence egg production before 55 wk (not laid), BW at AFE, coefficient of variation (CV) for AFE1, and coefficient of variation for BW at AFE1 of hens fed toward a High and Standard BW2 curve and photostimulated (PS) at wk 18 or 21.
| BW | PS | AFE (d) | SEM | MI (d) | SEM | Not laid (%) | SEM | BW at AFE (g) | SEM | AFE CV (%) | SEM | BW at AFE CV (%) | SEM | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BW | High | 178.1b | 5.3 | 41.8b | 5.3 | 5.8 | 5.15 | 3,157a | 54 | 16.2 | 3.46 | 11.7 | 0.90 | ||
| Standard | 194.7a | 5.8 | 58.2a | 5.8 | 17.6 | 2,824b | 59 | 23.2 | 13.2 | ||||||
| PS | 18 | 195.9a | 6.1 | 69.9a | 6.1 | 21.8a | 5.15 | 3046 | 62 | 28.2a | 3.46 | 13.3 | 0.90 | ||
| 21 | 177.0b | 4.9 | 30.0b | 4.9 | 1.7b | 2935 | 50 | 11.2b | 11.6 | ||||||
| BW × PS | High | 18 | 182.8 | 8.0 | 56.8 | 8.0 | 11.7 | 7.28 | 3176 | 81 | 25.2 | 4.89 | 14.4a | 1.27 | |
| 21 | 173.5 | 6.9 | 26.5 | 6.9 | 0.0 | 3137 | 70 | 7.2 | 9.0b | ||||||
| Standard | 18 | 209.0 | 9.1 | 83.0 | 9.1 | 31.9 | 2915 | 93 | 31.2 | 12.3a,b | |||||
| 21 | 180.4 | 7.0 | 33.4 | 7.0 | 3.3 | 2732 | 72 | 15.1 | 14.2a | ||||||
| Source of variation | ––––––––––––––––––––––––––––––– P-value ––––––––––––––––––––––––––––––– | ||||||||||||||
| BW | 0.036 | 0.036 | 0.121 | <0.001 | 0.225 | 0.290 | |||||||||
| PS | 0.017 | <0.001 | 0.012 | 0.166 | 0.025 | 0.237 | |||||||||
| BW × PS | 0.220 | 0.220 | 0.258 | 0.366 | 0.853 | 0.044 | |||||||||
a,bLSMeans within a column and treatment group lacking a common superscript differ (P < 0.05).
1Hens that did not commence egg production before wk 55 were excluded from the analysis.
2Hens followed either the breeder-recommended BW curve (Standard) or an accelerated BW curve reaching the 21 wk BW at 18 wk (High).