The current article served to provide the most up-to-date information regarding the causes of keel bone fracture. Although elevated and sustained egg production is likely a major contributing factor toward fractures, new information resulting from the development of novel methodologies suggests complementary causes that should be investigated. We identified 4 broad areas that could explain variation and increased fractures independent of or complementing elevated and sustained egg production: the age at first egg, late ossification of the keel, predisposing bone diseases, and inactivity leading to poor bone health. We also specified several topics that future research should target, which include continued efforts to link egg production and bone health, examination of noncommercial aves and traditional breeds, manipulating of age at first egg, a detailed histological and structural analysis of the keel, assessment of prefracture bone condition, and the relationship between individual activity patterns and bone health.

Simple SummaryCatching is the process that transfers birds from the poultry house to the transport modules. The catching process and its associated handling may lead to stress, injuries, mortality and reduced welfare for the animals. The aim of this pilot study was to investigate the effect of two manual broiler catching methods. Broilers were either caught by both legs and carried inverted to the drawers or caught under the abdomen and carried in an upright position. Effects of catching method on crating time, number of animals in the drawers, wing and leg fractures, animals on their back in the drawers and broilers dead-on-arrival were investigated. The results showed that the abdominal and upright method was faster and gave a lower and more consistent number of birds per drawer. In addition, this method tended towards fewer wing fractures. No broken legs, birds on their back in the drawers or broilers dead-on-arrival were observed in the study. Catching is a critical phase in the pre-slaughter chain, and this study shows that the catching and carrying method affects broiler welfare.AbstractCatching is the first step in the pre-slaughter chain for broiler chickens. The process may be detrimental for animal welfare due to the associated handling. The aim of this pilot study was to compare two different methods to manually catch broilers: Catching the broilers by two legs and carrying them inverted (LEGS) or catching the broilers under the abdomen and carrying them in an upright position (UPRIGHT). Wing and leg fractures upon arrival at the abattoir, animal density in the drawers, birds on their back, broilers dead-on-arrival and time to fill the transport modules were investigated. The results showed that mean crating time was shorter in the UPRIGHT method (p = 0.007). There was a tendency for more wing fractures in broilers caught by the LEGS (p = 0.06). The animal density in the drawers was lower and with a smaller range in the UPRIGHT method (p = 0.022). The results indicate that catching the broilers under the abdomen in an upright position may improve broiler welfare in terms of fewer wing fractures, more consistent stocking density in drawers and potentially reduced loading time.

Lameness and impaired walking ability in rapidly growing meat-type broiler chickens are major welfare issues that cause economic losses. This study analyzed the prevalence of impaired walking and its associations with production data, abattoir registrations, and postmortem tibia measurements in Norwegian broiler chickens. Gait score (GS) was used to assess walking ability in 59 different commercial broiler flocks (Ross 308) close to the slaughter d, 5,900 broilers in total, in 3 different geographical regions. In each flock, 100 arbitrary broilers were gait scored and 10 random broilers were culled to harvest tibias. Abattoir registrations on flock level were collected after slaughter. A total of 24.6% of the broilers had moderate to severe gait impairment. The broilers were sampled in 2 stages, first slaughterhouse/region, and then owner/flock. The final models showed that impaired gait is associated with first-week mortality (P < 0.05), region (P < 0.001), height of tibias mid-shaft (P < 0.05), and calcium content in the tibia ash (P < 0.05), and negatively associated with DOA (P < 0.05). The prevalence of impaired gait indicates that this is a common problem in the broiler industry in Norway, although the mean slaughter age is only 31 d and the maximum allowed animal density is relatively low. Impaired walking ability could not be predicted by the welfare indicators footpad lesion score, total on-farm mortality, and decreasing DOA prevalence. Further studies are needed to explore the relationship between first-week mortality and gait score.