Keel-bone damage and foot injuries in commercial laying hens in Denmark

Abstract

Keel-bone damage and foot injuries have a negative impact on welfare in laying hens. The extent of the problems in Danish commercial flocks of layers is unknown. Therefore, the aim of this study was to assess the current prevalence of keel-bone damage and foot injuries in Danish commercial flocks of laying hens and to investigate the effects of production system, housing system, hybrid and age. The occurrences of keel-bone damage, hyperkeratosis and missing toes were higher at 62 compared to 32 weeks of age, while the reverse was found for toe wounds, foot-pad lesions and bumble feet. There was no difference between barn and organic production systems in the risk of having keel-bone fractures and foot injuries, except that barn hens were more likely to have foot-pad lesions than organic hens (32 weeks: 16.1 vs 3.1%). Hens in multi-tiered systems were more likely to have keel-bone fractures compared to hens in single-tiered systems (62 weeks: 11.6 vs 4.9%). Of the four hybrids, Lohmann Brown Lite had a higher risk of keel-bone fractures, whereas bumble feet were found more frequently in Lohmann LSL. Keel-bone damage and foot injuries are less common in Danish non-cage systems compared to most of the reporting presently available from other countries. We suggest transnational studies, aimed at identifying the causal factors of this discrepancy, to increase existing knowledge on how to reduce incidences of keel-bone damage and foot injuries.

Radiographic Evaluation of Keel Bone Damage in Laying Hens—Morphologic and Temporal Observations in a Longitudinal Study

“…The animals were examined over a period of 10 months during which each animal was assessed 11 times (22,25,28,33,37,40,45,49,54,57, and 61 weeks of age). For better understanding, the term "observation Phase (P)" from 1 to 11 is used hereafter.…”

“…In this study, 97.0% of the animals had at least one fracture and 99.3% had at least one lesion at the end of the study (61 weeks of age). Previous studies have suggested less frequent occurrence (5,(20)(21)(22)(23)(24) with typically 50-80% of surveyed hens manifesting keel fractures by the end of lay using palpation or dissection. As a potential explanation for the relatively higher frequency seen in the current study, our protocol allowed for recent, healed, and minor fractures to be diagnosed (7,9) which could be missed with palpation and/or dissection.…”

Welfare Consequences of Omitting Beak Trimming in Barn Layers

“…The barns system in Denmark consists of either single-tiered percheries or multitiered aviaries. The participating producers were originally recruited for another research project ( 17 , 33 ); 10 of the original 13 barn egg producers agreed to participate in this study. The hens were housed according to the EU regulations for barn production systems ( 34 ), i.e., the barn hens were housed at a stocking density of 9 hens/m 2 and with no outdoor access.…”

“…During all visits, a total of 100 hens were caught in different areas of the house, and the condition of plumage, skin, feet, and keel bone of each bird was assessed by trained observers ( 33 ) using the scoring protocol developed in the CORE Organic project HealthyHens ( 35 ). A sample size of 100 hens was chosen based on the recommendation of the Welfare Quality ® protocol ( 36 ) and a sample size calculation ( 33 ).…”

Keel bone damage in laying hens reared in different production systems in Serbia

“…During the last decade, numerous studies, done mostly in the EU countries, have documented fractures and deformation of the keel bone in laying hens, which range between 5% and 97%, depending on the housing system and hen age (Rodenburg et al, 2008;Wilkins et al, 2011;Petrik et al, 2015;Riber and Hinrichsen, 2016;Regmi et al, 2016). So far, no similar research was conducted in our country.…”