Impact of Nutrient Density, Feed Form, and Photoperiod on the Walking Ability and Skeletal Quality of Broiler Chickens

• Published in: Poultry science 2007-10, Vol.86 (10), p.2117-2125
• Main Authors: Brickett, K.E, Dahiya, J.P, Classen, H.L, Annett, C.B, Gomis, S
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animal Nutritional Physiological Phenomena; animal welfare; Animals; Body Weight; Bone and Bones - drug effects; Bone and Bones - radiation effects; bone density; Bone Density - drug effects; Bone Density - radiation effects; bone strength; broiler chickens; broiler feeding; Chickens - growth & development; Diet - veterinary; Female; females; gait; gender differences; locomotion; Male; males; mash feed; Minerals; musculoskeletal system; nutrient density; pelleted feeds; Photoperiod; Skeleton; walking; Walking - physiology
• ISSN: 0032-5791; 1525-3171
• DOI: 10.1093/ps/86.10.2117

The aim of this study was to examine the main and interaction effects of 3 dietary nutrient densities (low-, medium-, high-density), 2 feed forms (mash, pellet), and 2 lighting programs (20L:4D, 12L:12D) on the walking ability and skeletal quality of broiler chickens raised to a young age (35 d). Forty-eight birds per treatment (nutrient density x feed form x lighting program subclass) were randomly selected (0 d) for assessment of their gait score (GS) and BW at 11, 18, 25, and 32 d. Samples of birds from various GS classifications were selected at 32 d for radiographs and histology of the femur and tibiotarsus. Bone ash (BA) content was evaluated at 35 d from the right tibiotarsus to assess bone quality. Overall, the mean GS values were low (GS =3. Broilers fed mash had a higher BA content (50.6%) than birds fed pellet diets (49.8%), and the 12L:12D value (50.5%) was greater than for 20L:4D (48.9%). Last, males had a lower BA content (49.8%) than females (50.6%). A positive correlation existed between BW and GS based on sex, where BW at 11, 18, and 25 d affected bird mobility at 32 d (r² = 0.39, 0.49, and 0.50 for males; r² = 0.34, 0.37, and 0.36 for females, respectively). Radiography and histology were unaffected by GS. This study confirmed that a reduced growth rate improved GS but also demonstrated that overall bird mobility was good and the incidence of skeletal disease was low.