Table2_Japanese quails (Cortunix Japonica) show keel bone damage during the laying period—a radiography study.XLSX

Keel bone damage is an important welfare issue in laying hens and can occur with a high prevalence of up to 100% of hens within one flock. Affected hens suffer from pain. Although multiple factors contribute to the prevalence and severity of keel bone damage, selection for high laying performance appears to play a key role. With up to 300 eggs/year, Japanese quails show a high laying performance, too, and, thus, may also show keel bone damage. However, to our knowledge, there are no scientific results on keel bone damage in Japanese quails to date. Therefore, the aim of this study was to assess whether keel bone fractures and deviations occur in Japanese quails and to obtain more detailed information about the development of their keel bone during the production cycle. A group of 51 female quails were radiographed at 8, 10, 15, 19, and 23 weeks of age. The X-rays were used to detect fractures and deviations and to measure the lateral surface area, length, and radiographic density of the keel bone. In addition, the length of the caudal cartilaginous part of the keel bone was measured to learn more about the progress of ossification. At 23 weeks of age, quails were euthanized and their macerated keel bones assessed for fractures and deviations. Both keel bone deviations and keel bone fractures were detected in the Japanese quails. In the 23rd week of age, 82% of the quails had a deviated keel bone as assessed after maceration. Furthermore, there was a decrease in radiographic density, lateral surface area, and length of the keel bone between weeks of age 8 and 19. This could indicate a general loss of bone substance and/or demineralization of the keel bone. Our study shows that keel bone damage is not only a problem in laying hens but also affects female Japanese quails.</p

Table1_Japanese quails (Cortunix Japonica) show keel bone damage during the laying period—a radiography study.XLSX

Keel bone damage is an important welfare issue in laying hens and can occur with a high prevalence of up to 100% of hens within one flock. Affected hens suffer from pain. Although multiple factors contribute to the prevalence and severity of keel bone damage, selection for high laying performance appears to play a key role. With up to 300 eggs/year, Japanese quails show a high laying performance, too, and, thus, may also show keel bone damage. However, to our knowledge, there are no scientific results on keel bone damage in Japanese quails to date. Therefore, the aim of this study was to assess whether keel bone fractures and deviations occur in Japanese quails and to obtain more detailed information about the development of their keel bone during the production cycle. A group of 51 female quails were radiographed at 8, 10, 15, 19, and 23 weeks of age. The X-rays were used to detect fractures and deviations and to measure the lateral surface area, length, and radiographic density of the keel bone. In addition, the length of the caudal cartilaginous part of the keel bone was measured to learn more about the progress of ossification. At 23 weeks of age, quails were euthanized and their macerated keel bones assessed for fractures and deviations. Both keel bone deviations and keel bone fractures were detected in the Japanese quails. In the 23rd week of age, 82% of the quails had a deviated keel bone as assessed after maceration. Furthermore, there was a decrease in radiographic density, lateral surface area, and length of the keel bone between weeks of age 8 and 19. This could indicate a general loss of bone substance and/or demineralization of the keel bone. Our study shows that keel bone damage is not only a problem in laying hens but also affects female Japanese quails.</p

Table3_Japanese quails (Cortunix Japonica) show keel bone damage during the laying period—a radiography study.XLSX

Keel bone damage is an important welfare issue in laying hens and can occur with a high prevalence of up to 100% of hens within one flock. Affected hens suffer from pain. Although multiple factors contribute to the prevalence and severity of keel bone damage, selection for high laying performance appears to play a key role. With up to 300 eggs/year, Japanese quails show a high laying performance, too, and, thus, may also show keel bone damage. However, to our knowledge, there are no scientific results on keel bone damage in Japanese quails to date. Therefore, the aim of this study was to assess whether keel bone fractures and deviations occur in Japanese quails and to obtain more detailed information about the development of their keel bone during the production cycle. A group of 51 female quails were radiographed at 8, 10, 15, 19, and 23 weeks of age. The X-rays were used to detect fractures and deviations and to measure the lateral surface area, length, and radiographic density of the keel bone. In addition, the length of the caudal cartilaginous part of the keel bone was measured to learn more about the progress of ossification. At 23 weeks of age, quails were euthanized and their macerated keel bones assessed for fractures and deviations. Both keel bone deviations and keel bone fractures were detected in the Japanese quails. In the 23rd week of age, 82% of the quails had a deviated keel bone as assessed after maceration. Furthermore, there was a decrease in radiographic density, lateral surface area, and length of the keel bone between weeks of age 8 and 19. This could indicate a general loss of bone substance and/or demineralization of the keel bone. Our study shows that keel bone damage is not only a problem in laying hens but also affects female Japanese quails.</p

Proportion of deviated keel bone area (POD) (back-transformed LSM and upper and lower bounds of the 95% confidence interval) in %.

<p>POD was affected by the three-way interaction between housing system, layer line and age (p<0.01).</p

Radiographic examination of keel bone damage in living laying hens of different strains kept in two housing systems

<div><p>A high prevalence of deviations and fractures of the keel bone is a widespread welfare problem in laying hens. The aim of this study was to experimentally investigate this multifactorial problem throughout the laying period and to compare the prevalence and severity in different layer lines and different housing systems. High performing white (WLA) and brown (BLA) pure bred layer lines and low performing white (R11, G11) and brown layer lines (L68) were kept in both single cages and a floor housing system. A total of 97 hens (19 or 20 from each line, respectively) were repeatedly radiographed in the 35^th, 51^st and 72^nd week of age. Fracture prevalence increased with age (p<0.001). The proportion of deviated keel bone area increased only for caged BLA, WLA and R11 hens (p<0.05) and was significantly higher for caged WLA and R11 hens compared to floor-housed WLA and R11 hens in the 72^nd week of age (p<0.05). In the 72^nd week of age hens in the floor housing system showed significantly more fractures than hens kept in cages (p<0.05). Prevalence of keel bone deviations was significantly higher in the white layer line R11 but significantly lower in the white layer line G11 compared to both brown layer lines and WLA (p<0.05). Brown layers showed significantly more fractures than white layers (p<0.05) in the 51^st and 72^nd week of age. Within the brown layers there was a significantly lower prevalence of deviations (p<0.05) and fractures (p<0.05) in the low performing (L68) compared to the high performing line (BLA). Our results show a different development of keel bone damage in caged compared to floor-housed hens under experimental conditions. Additionally, they indicate genetic effects on keel bone damage.</p></div

A deviated keel bone.

<p>The keel bone surface area is circumscribed with blue color; the area of deviation is circumscribed with red color. The blue-red line marks the straight line between the start and end point of thedeviated outline.</p

A fractured keel bone without callus formation.

<p>The arrow shows the fracture, a thin, black line.</p

Fracture prevalence.

<p>Each bar represents the total amount of radiographed and evaluated hens of one layer line within one housing system. The grey part of a bar shows the part of hens with a fractured keel bone, the white part those without any fracture. The numbers written in the bars show the total numbers of affected or non-affected hens, respectively. Fracture prevalence was affected by layer line (p<0.05 at all three ages) and age (p<0.001). Housing system significantly influenced fracture prevalence in the 72^nd week of age (p<0.05).</p

Positioning of the animal on the X-ray detector.

<p>The red lighted area indicates the radiation field center.</p

A fractured keel bone with callus formation.

<p>The arrow shows the fracture callus.</p