Effects of genotype and housing system on some bone biomechanical characteristics in broiler chickens

Abstract

The aim of this study was to determine the effects of two genotypes (slow-growing and fast-growing) and three housing systems (deep litter, plastic slat and free-range) on some bone biomechanical properties of broiler chickens and to evaluate the interaction between genotype and housing systems. Broilers from two genotypes were reared at three different housing conditions. Fifteen bones were randomly selected from each housing system in both slow-growing and fast-growing groups, and the experiment was performed on 90 bones in total. To determine bone characteristic and biomechanical traits of tibiotarsi, bones collected from right leg and then weighed, cortical area measurements and three-point bending tests were applied. Both live body weight and carcass weight were significantly affected by genotype and housing systems. There was no interaction between genotype and housing system in terms of bone weight, cortical area, breaking strength, bending strength, and deflection. Also, housing systems had no statistical effect on these parameters. Fast-growing broilers were significantly had heavier tibiotarsi, larger cortical area and higher breaking strength than slow-growing broilers, while bending strength was significantly lower in fast-growing broilers. Deflection was not affected by genotype or by housing system. In conclusion, bone geometry and biomechanical properties were not affected by housing systems but by genotype. Fast-growing broilers had better bone morphology and stronger bones than slow-growing genotype. Therefore, fast-growing genotype can provide positive effects on bone growth and mechanical properties in broilers.