Document Type : Full Research Paper
Authors
1
Research&development, Makian Phosphate company,Mashhad,,Iran.
2
Department of animal science, Islamic Azad University, Kashmar, Iran
3
Department of animal science,Kashmar Branch,Islamic Azad University,Kashmar,Iran
Abstract
Introduction: The effectiveness of mineral sources, including zinc, on the performance and egg quality of laying birds has not been fully investigated. Objective: To investigate different sources of zinc (organic and inorganic) on the immune system, antioxidant activity, performance and enrichment in 80-week-old Leghorn laying hens, with seven treatments and five replications in a completely randomized design. Materials and Methods: The experiment was conducted on 175 White Leghorn laying hens of the w36 line at the age of 80 weeks for 12 weeks at the research poultry farm of Islamic Azad University, Kashmar city branch, Khorasan Razavi province. The treatments included: one: control (base diet), two: base diet + 15 mg/kg zinc sulfate, three: base diet + 30 mg/kg zinc sulfate, four: base diet + 45 mg/kg zinc sulfate, five: base diet + 15 mg/kg organic zinc, six: base diet + 30 mg/kg organic zinc, seven: base diet + 45 mg/kg organic zinc. Results: According to the results, feed intake increased significantly with the addition of different levels and sources of zinc. In treatments four, five, six and seven, the highest egg weight and improved conversion ratio were observed. The highest number and mass of eggs were in treatment four compared to the control treatment. Both supplements increased SOD activity at all levels. Immunoglobulins G and M were significantly affected by the experimental treatments. The amount of zinc stored in eggshell was not affected, but in bone, egg yolk, blood serum and liver it was significantly affected by the experimental treatments. Conclusion: Both zinc sources improve feed intake, feed conversion ratio, performance, safety, antioxidant activity, bioavailability and egg enrichment, but the recommended level for this experiment is 45 mg/kg of organic and inorganic sources.
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