This study aimed to compare the effect of Zn, Cu and Fe glycine chelates on the proximate composition, cholesterol levels, fatty-acid profile and dietary value of the thigh meat of broiler chickens. The experiment involved three hundred and fifty Ross 308 chickens divided into seven groups. The chickens were administered Zn, Cu and Fe glycine chelates in an amount corresponding to 50% of the requirement or 25% of the requirement for 42 days. It was found that the use of Zn, Cu and Fe glycine chelates did affect the fatty acid profile and dietary value of meat. A positive impact was most frequently (p < 0.05) noted in chickens receiving Zn chelate in an amount covering 50% of the requirement: the lowest levels of SFA and atherogenic and thrombogenic indices, the highest content of PUFA n-3 and PUFA/SFA ratios and hypocholesterolemic/hypercholesterolemic indices. Positive effects were more often recorded for chickens receiving Zn in an amount corresponding to 50% of the requirement. The results did not show that the use of Cu and Fe glycine chelates can reduce the dietary value of thigh meat in broiler chickens since, generally, the outcomes were not worse than those in the control group. It should be highlighted that due to ambiguous results, it is impossible to determine a dose of Cu and Fe glycine chelate which would be more efficient for broiler chickens. However, chickens receiving chelates in amounts corresponding to 25% of the requirement showed far better results.
Keywords: Zn, Cu and Fe; broiler chickens; dietetic value; fatty acid; glycine chelate; thigh meat.