Effect of copper glycinate chelate on biomechanical, morphometric and chemical properties of chicken femur

The effect of Cu in the form of glycinate chelate, added to chicken feed mixtures, on biomechanical, morphometric and chemical parameters of chicken femur bones was evaluated at 6 weeks of age. Three hundred one-day-old Ross 308 male chicks were divided into 6 groups each in 5 repetitions of 10 chicks. The basal feed mixtures contained: starter 6.1 mg·kg^-1 Cu, grower 6.21 mg·kg^-1 Cu, finisher 5.91 mg·kg^-1 Cu. In the experiment 8, 4 or 2 mg·kg^-1 of copper were added to the premix (containing no Cu) in the form of copper sulfate (S-Cu) or as copper glycinate chelate (Gly-Cu). The highest cortical index and maximum elastic strength towards bone weight were observed when S-Cu was added to the mixture at 25% of the requirement. Higher values of the maximum elastic strength were recorded in groups receiving 100% and 50% Gly-Cu compared to the group fed with 100% and 25% S-Cu. In chickens receiving Gly-Cu significantly higher Ix values were recorded in comparison with the group receiving 50% S-Cu. As an alternative to iron sulfate Ross 308 broiler chickens can be fed with Fe in the form of copper glycinate chelate. The use of chelate in the amount limited to 10 or 20 mg·kg^-1 did not result in worse physicochemical, strength and morphometric parameters of chicken femurs compared to the recommended dose (40 mg·kg^-1).