Effect of Perches and Stocking Density on Tibial Dyschondroplasia and Bone Mineralization as Measured by Bone Ash in Broiler Chickens

Abstract

Exercise through perching has been suggested as a method to reduce the impact of leg problems in broiler chickens. The goal of this research was to determine the effects of stocking density and perch availability on the incidence of tibial dyschondroplasia (TD) and the level of bone ash in broiler chickens. The incidence of TD was lowest in birds raised at the higher densities with 20 and 15 birds/m2 and highest at stocking densities of 10 birds/m2. This pattern was positively correlated with the perching frequency of chickens, as observed at the different experimental densities and reported previously. Except for controls, which had no TD lesions compared to birds with access to perches, TD incidence was lowest in pens with horizontal perches and highest in pens with a combination of horizontal and sloping perches. These differences were not statistically significant. Percentage bone ash was lower in birds with TD than in normal birds (P < 0.05). Bone ash was not affected by stocking density or perch treatment. TD incidence was similar for both sexes; however, percentage bone ash was significantly lower in males than in females (P < 0.02). These results suggest that TD and faster growth rate in males may have a negative impact on bone mineralization in broiler chickens. However, it is unclear from our results whether providing broilers with access to perches can actually improve bone mineralization or prevent TD.