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Standards for feeder (a.k.a. feed trough) space allowance (SA) are based primarily on studies in conventional cages where laying hens tend to eat simultaneously, limiting feeder space. Large furnished cages (FC) offer more total space and opportunities to perform a greater variety of behaviors, which may affect feeding behavior and feeder space requirements. Our objective was to determine the effects of floor/feeder SA on behavior at the feeder. LSL-Lite hens were housed in FC equipped with a nest, perches, and a scratch mat. Hens with SA of either 520 cm2 (Low; 8.9 cm feeder space/hen) or 748 cm2 (High; 12.8 cm feeder space/hen) per bird resulted in groups of 40 vs. 28 birds in small FC (SFC) and 80 vs. 55 in large FC (LFC). Chain feeders ran at 0500, 0800, 1100, 1400, and 1700 with lights on at 0500 and off at 1900 hours. Digital recordings of FC were scanned at chain feeder onset and every 15 min for one h after (5 scans × 5 feeding times × 2 d) to count the number of birds with their head in the feeder. All occurrences of aggressive pecks and displacements during 2 continuous 30-minute observations at 0800 h and 1700 h also were counted. Mixed model repeated analyses tested the effects of SA, cage size, and time on the percent of hens feeding, and the frequency of aggressive pecks and displacements. Surprisingly, the percent of birds feeding simultaneously was similar regardless of cage size (LFC: 23.0 ± 0.9%; SFC: 24.0 ± 1.0%; P = 0.44) or SA (Low: 23.8 ± 0.9%; High: 23.3 ± 1.0%; P = 0.62). More birds were observed feeding at 1700 h (35.3 ± 0.1%) than any at other time (P < 0.001). Feeder use differed by cage area (nest, middle, or scratch) over the d (P < 0.001). The frequency of aggressive pecks was low overall and not affected by SA or cage size. Frequency of displacements was also low but greater at Low SA (P = 0.001). There was little evidence of feeder competition at the Low SA in this study., (© The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.)

Osteoporosis in laying hens has been a production and welfare concern for several decades. The objective of this study was to determine whether differing opportunities for exercise during pullet rearing influences long-term bone quality characteristics in end-of-lay hens. A secondary objective was to assess whether differing opportunities for exercise in adult housing systems alters bone quality characteristics in end-of-lay hens. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S), or 60-bird furnished cages (FC-L) for adult housing. Wing and leg bones were collected at the end-of-lay to quantify bone composition and strength using quantitative computed tomography and bone breaking strength (BBS). At the end-of-lay, Avi hens had greater total and cortical cross-sectional area (P < 0.05) for the radius and tibia, greater total bone mineral content of the radius (P < 0.001), and greater tibial cortical bone mineral content (P = 0.029) than the Conv hens; however, total bone mineral density of the radius (P < 0.001) and cortical bone mineral density of the radius and tibia (P < 0.001) were greater in the Conv hens. Hens in the FC-L had greater total bone mineral density for the radius and tibia (P < 0.05) and greater trabecular bone mineral density for the radius (P = 0.027), compared to hens in the FC-S and CC. Total bone mineral content of the tibia (P = 0.030) and cortical bone mineral content of the radius (P = 0.030) and tibia (P = 0.013) were greater in the FC-L compared to the CC. The humerus of Conv hens had greater BBS than the Avi hens (P < 0.001), and the tibiae of FC-L and FC-S hens had greater BBS than CC hens (P = 0.006). Increased opportunities for exercise offered by the aviary rearing system provided improved bone quality characteristics lasting through to the end-of-lay., (© The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.)

Increased load-bearing exercise improves bone quality characteristics in a variety of species, including laying hens. Providing increased opportunities for exercise during the pullet rearing phase, a period of substantial musculoskeletal growth, offers a proactive approach to reducing osteoporosis by improving bone composition. The main objective of this study was to determine whether differing opportunities for exercise during rearing influences pullet musculoskeletal characteristics. Two flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either standard, conventional cages (Conv) or an aviary rearing system (Avi) from day-old chicks until 16 wk of age. The keel bone and the muscles and long bones of the wings and legs were collected at 16 wk to measure muscle growth differences between rearing treatments and quantify bone quality characteristics using quantitative computed tomography (QCT) and bone breaking strength (BBS) assessment. Keel bone characteristics and muscle weights were adjusted for BW and analyses for QCT and BBS included BW as a covariate. At 16 wk of age, rearing system had an effect on the majority of keel bone characteristics (P < 0.05). The length of the keel metasternum, caudal tip cartilage length, and the overall percentage of cartilage present on the keel at 16 wk was greater in the Avi pullets compared to the Conv pullets (P < 0.01). Wing and breast muscle weights of the Avi pullets were greater than the Conv pullets (P < 0.001), but leg muscle weights were greater in the Conv pullets (P = 0.026). Avi pullets had greater total bone density, total cross-sectional area, cortical cross-sectional area, total bone mineral content, and cortical bone mineral content than Conv pullets for the radius, humerus, and tibia (P < 0.001). Avi pullets had greater BBS compared to the Conv pullets for the radius, humerus, and tibia (P < 0.01). Increased opportunities for exercise offered by the aviary rearing system increased muscle and bone growth characteristics in pullets at 16 wk of age., (© The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.)

High flock-level prevalence of keel-bone fractures and deviations in laying hens are commonly reported across various housing systems; however, few longitudinal studies exist, especially for furnished and conventional cage systems. Load-bearing exercise improves bone strength and mineral composition in laying hens and has the potential to reduce keel-bone damage, especially if exercise is allowed during critical periods of bone growth throughout the pullet rearing phase. The objective of this study was to determine the prevalence of keel-bone damage in laying hens housed in furnished and conventional cages, and assess whether opportunities for exercise during the pullet rearing phase influenced the prevalence of keel-bone damage throughout the laying period. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets/flock were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S) or 60-bird furnished cages (FC-L) for adult housing. Keel-bone status was determined by palpation at 30, 50, and 70 wk of age. Age (P < 0.001) and rearing system (P < 0.001) had an effect on the presence of keel-bone fractures. The presence of fractures increased with age, and hens raised in the Avi system had a lower percentage of fractures (41.6% ± 2.8 SE) compared to hens reared in the Conv system (60.3% ± 2.9 SE). Adult housing system did not have an effect on the percentage of keel fractures (P = 0.223). Age had an effect on the presence of deviations (P < 0.001), with deviations increasing with age. Rearing system (P = 0.218) and adult housing system (P = 0.539) did not affect the presence of deviations. Keel fractures and deviations were strongly associated with each other at all ages: 30 wk: (P < 0.001); 50 wk: (P < 0.001); and 70 wk: (P < 0.001). Increased opportunities for exercise provided by an aviary rearing system reduced the prevalence of keel-bone fractures through the end-of-lay., (© 2017 Poultry Science Association Inc.)