Dietary phytase effects on copper requirements of broilers

Area of Science:

• Animal Nutrition
• Poultry Science
• Trace Mineral Metabolism

Background:

• Information on copper (Cu) availability in plant-based broiler feed, especially with phytase, is limited.
• Understanding Cu requirements is crucial for optimizing broiler performance and health.

Purpose of the Study:

• To evaluate the copper requirements of broilers fed corn-soy diets with or without phytase.
• To determine the effects of phytase and supplemental copper on broiler growth, feed conversion, and copper metabolism.

Main Methods:

• A 2x5 factorial experiment with 640 male Cobb 500 broilers was conducted.
• Diets included either no phytase or excess phytase, with five graded levels of supplemental copper (8.05 to 19.45 mg/kg).
• Growth performance, bone parameters, and tissue/excreta copper content were analyzed using regression models.

Main Results:

• Phytase addition significantly improved body weight gain (BWG) and reduced feed conversion ratio (FCR).
• Phytase increased ileal digestible copper by 8.8%, but no interactions between copper and phytase were observed.
• Supplemental copper linearly increased liver copper content and excreta copper, as well as retention, but did not affect performance or bone parameters.

Conclusions:

• Phytase effectively enhances broiler performance and copper digestibility, suggesting it can reduce dietary copper needs.
• Current supplemental copper levels up to 19.45 mg/kg in corn-soy diets do not further improve broiler performance when phytase is present.
• Further research may be needed to establish optimal copper levels in phytase-supplemented broiler diets.