Table 3.
Bone traits of the tibia in 73-week-old laying hens subjected to different rearing and adult housing systems as measured by quantitative computed tomography.
| Density mg/cm3 (±SE) | Cross-sectional area mm2 (±SE) | Bone mineral content mg/mm (±SE) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total | Cortical | Trabecular | Total | Cortical | Trabecular | Total | Cortical | Trabecular | ||
| Rearing 1 | ||||||||||
| Conv | 589.2 (7.68) | 1063.2 (6.52) | 208.19 (6.37) | 39.1 (0.45) | 17.3 (0.42) | 21.2 (0.45) | 23.1 (0.36) | 18.4 (0.39) | 4.4 (0.13) | |
| Avi | 590.6 (8.40) | 1031.5 (7.03) | 198.7 (6.93) | 40.4 (0.47) | 19.0 (0.45) | 20.4 (0.50) | 23.9 (0.39) | 19.6 (0.43) | 4.0 (0.15) | |
| DF | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | |
| F-value | 0.01 | 12.90 | 1.08 | 5.61 | 9.12 | 1.29 | 2.36 | 4.86 | 4.33 | |
| P-value | 0.905 | <0.001 | 0.301 | 0.019 | 0.003 | 0.259 | 0.127 | 0.029 | 0.039 | |
| Adult housing 2 | ||||||||||
| FC-L | 620.3 (8.65)a | 1061.3 (7.19) | 213.8 (7.11) | 39.2 (0.48) | 18.9 (0.46) | 19.2 (0.51)a | 24.3 (0.40)a | 19.9 (0.44)a | 4.0 (0.15) | |
| FC-S | 571.9 (12.42)b | 1040.0 (10.00) | 197.6 (10.10) | 40.4 (0.64) | 17.9 (0.65) | 21.7 (0.73)b | 23.2 (0.57)a,b | 18.7 (0.61)a,b | 4.3 (0.21) | |
| CC | 577.5 (7.92)b | 1040.7 (6.72) | 198.9 (6.57) | 39.6 (0.46) | 17.6 (0.43) | 21.4 (0.47)b | 22.9 (0.37)b | 18.3 (0.41)b | 4.2 (0.14) | |
| DF | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | |
| F-value | 8.34 | 3.01 | 1.51 | 1.66 | 2.44 | 6.21 | 3.60 | 4.52 | 0.73 | |
| P-value | <0.001 | 0.053 | 0.226 | 0.195 | 0.092 | 0.003 | 0.030 | 0.013 | 0.484 | |
| Interaction R*A 3 | ||||||||||
| Conv * FC-L | 604.1 (13.00) | 1076.8 (10.40) | 212.6 (10.54) | 38.8 (0.66) | 17.6 (0.67) | 20.5 (0.77) | 23.4 (0.60) | 18.9 (0.64) | 4.3 (0.22) | |
| Conv * FC-S | 574.6 (15.54) | 1053.5 (12.33) | 210.3 (12.56) | 39.5 (0.77) | 17.1 (0.80) | 21.9 (0.92) | 22.8 (0.72) | 18.0 (0.76) | 4.6 (0.27) | |
| Conv * CC | 589.0 (10.99) | 1056.1 (8.95) | 201.7 (8.97) | 39.0 (0.58) | 17.1 (0.58) | 21.0 (0.65) | 23.0 (0.51) | 18.1 (0.55) | 4.3 (0.19) | |
| Avi * FC-L | 636.5 (11.40) | 1045.7 (9.22) | 214.9 (9.28) | 39.5 (0.59) | 20.1 (0.60) | 17.9 (0.67) | 25.2 (0.52) | 20.9 (0.57) | 3.8 (0.20) | |
| Avi * FC-S | 569.2 (19.38) | 1023.5 (15.29) | 185.0 (15.64) | 41.4 (0.95) | 18.8 (0.99) | 21.5 (1.14) | 23.6 (0.90) | 19.3 (0.94) | 3.9 (0.33) | |
| Avi * CC | 566.0 (11.40) | 1025.2 (9.25) | 196.2 (9.30) | 40.2 (0.60) | 18.0 (0.60) | 21.7 (0.67) | 22.8 (0.53) | 18.5 (0.57) | 4.2 (0.20) | |
| DF | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | 114 | |
| F-value | 2.84 | 0.00 | 0.65 | 0.36 | 0.93 | 2.57 | 1.89 | 1.06 | 0.70 | |
| P-value | 0.062 | 0.995 | 0.524 | 0.699 | 0.397 | 0.081 | 0.155 | 0.351 | 0.497 | |
a,bWithin a column, for each treatment variable (Adult housing, Interaction R*A), means lacking a common superscript differ (P < 0.05).
1Pullets housed in a conventional rearing system (Conv) or an aviary rearing system (Avi) until 16 wk of age, Flocks 1 to 4.
2Adult hens placed into furnished cage- large (FC-L), furnished cage-small (FC-S), or conventional cages (CC) from 16 to 73 wk of age, Flocks 1 to 4.
3Interaction between rearing housing system and adult housing system.