A comparison between leg problems in Danish and Swedish broiler production
In Denmark and Sweden, surveys were undertaken to estimate the prevalence of leg problems in conventional broiler production. The Danish survey included 28 Ross 208 flocks, and the Swedish survey included 15 Ross 208 and 16 Cobb flocks. Leg problems included reduced walking ability
(gait), tibial dyschondroplasia (TD), varus/valgus deformations (VV) and foot-pad dermatitis (FPD). Danish Ross chicks showed a significantly higher prevalence of gait score > 0, gait score > 2 and TD, but a lower prevalence of VV, than Swedish Ross chicks. Cobb chicks showed a significantly
higher prevalence of gait score > 0, gait score > 2 and TD than Swedish Ross chicks, a significantly higher prevalence of VV than Danish Ross chicks, and a significantly lower prevalence of FPD than both Danish and Swedish Ross chicks. The two genotypes of Swedish chicks showed similar
relationships between body weight and probability of gait score > 0, TD and VV, indicating that the difference in prevalence of these leg problems may be due to the difference in mean body weight at slaughter age. At body weights below 2300 g, Danish chicks showed a higher probability of
gait score > 2 than Swedish chicks. Furthermore, at body weights below 1900 g, Danish chicks had a higher probability of TD than Swedish chicks, whereas at body weights above 2200 g they had a lower probability of TD. This indicates that the difference in prevalence of TD between Danish
and Swedish chicks was due to differences in mean body weight at slaughter age as well as housing conditions. Therefore, further studies on the risk factors in relation to management and housing conditions are required.