The effects of four stocking and water nipple densities on broiler performance and carcass traits were measured in two trials. The stocking densities of 23.8, 17.9, 14.3, and 11.9 birds/m2 corresponded to 260, 195, 156, and 130 birds per pen, respectively. The water nipple densities were 5, 10, 15, and 20 birds per water nipple. Birds in Trial 1 were processed at Day 39 and those in Trial 2 were processed at Day 42. Water and feed were provided ad libitum and light was provided 23 h/ d. Water nipple density had no effect on broiler performance or carcass quality. Birds grown at 23.8 birds/m2 had lower BW (1,898 g) and carcass weights (1,334 g), whereas birds grown at 14.3 birds/m2 had the highest BW (1,985 g) and carcass weights (1,432 g). Although the treatment with 23.8 birds/m2 gave the lowest BW, the yield of broilers per unit of floor space was highest (46.0 kg/m2). The coefficient of variation for BW was higher in the treatment with 11.9 birds/m2 (15.3 %) than in the other treatments (13.0%). The birds in the treatment with 11.9 birds/m2 consumed the least feed (2,993 g/bird) and those in the 14.3 birds/m2 treatment consumed the most feed (3,183 g/bird). The amount of water consumed and the water to feed ratio was highest in the 23.8 birds/m2 treatment (5,546 mL/bird and 1.85 mL/g, respectively). Stocking density had no effect on mortality, breast yield, carcass grading, incidence of scratches, or carcass quality. It was concluded high yield per unit area with good carcass quality could be achieved when ventilation rate and air circulation were adequate.

No abstract

Limited opportunity for movement and load-bearing exercise for conventionally caged laying hens leads to bone loss and increased susceptibility to osteoporosis, bone fractures, and cage layer fatigue, all of which compromise hen welfare and have negative consequences for production. The objective of this study was to compare bone mineral density (BMD) and strength measures of White Leghorns housed in conventional battery cages (CONV), cages modified to incorporate a nest box and perch (MOD), and commercially available, furnished colony cages with (CWDB) or without (CWODB) a raised dust bath. Hens reared on floor litter were randomly allocated to 1 of 4 cage systems at 19 wk of age. Hen-day production and egg quality were measured between 20 and 64 wk. At 65 wk, hens were killed, and right femur, tibia, and humerus were excised. Bone mineral density was assessed using quantitative computed tomography, and breaking strength was measured with an Instron Materials Tester. In the femur and tibia, CONV hens exhibited lower total BMD, bone mass, cortical bone area, cortical bone mass, and bone-breaking strength than CWDB, CWODB, and MOD hens. Density and cross-sectional area of bone in the trabecular space was highest in CONV. In the humerus, total and cortical BMD and mass and breaking strength values were higher for colony-housed birds than hens in CONV and MOD. The MOD birds did not exhibit increased humeral BMD or strength measures over CONV hens. These findings provide evidence that hens housed in modified and colony cages, furnished systems that promote load-bearing movement, are better able to preserve cortical structural bone than conventionally caged hens and simultaneously have stronger bones. Furthermore, inclusion of raised amenities that encourage wing loading is necessary to reduce humeral cortical bone loss. The overall absence of correlation between egg production or quality and bone quality measures also suggests that improved bone quality in CWDB, CWODB, and MOD furnished cages is not the result of lowered egg production or quality.

2006;48:741-748)