Corn expressing an Escherichia coli-derived phytase gene: comparative evaluation study in broiler chicks

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Genetically Modified Organisms

Background:

• Poultry diets often require inorganic phosphorus (P) supplementation.
• Phytase enzymes can improve P availability from plant-based feedstuffs.
• Developing novel phytase sources, like corn-based phytase (CBP), is crucial for sustainable animal nutrition.

Purpose of the Study:

• To compare the efficacy of CBP and a microbial phytase (Quantum) in broiler chicken diets.
• To evaluate the impact of these phytases on growth performance, bone mineralization, and nutrient utilization.
• To determine the optimal supplementation level of CBP in P-deficient diets.

Main Methods:

• Two 14-day broiler chicken studies involving 288 and 192 birds, respectively.
• Corn-soybean meal-based diets included a positive control, negative control (NC) low in P and Ca, and NC supplemented with varying phytase units (FTU) of CBP or Quantum.
• Growth performance, bone mineralization (tibia ash), and nutrient digestibility were assessed.

Main Results:

• Weight gain and tibia ash showed quadratic responses to CBP supplementation (P < 0.01).
• Birds fed 3,630 FTU/kg of CBP or Quantum had comparable performance to the positive control.
• Supplemental phytase significantly increased ileal and total tract P and Ca digestibility compared to the NC diet (P < 0.01).

Conclusions:

• Corn-based phytase (CBP) is efficacious in P-deficient broiler diets.
• CBP improves growth performance and P utilization indices in broiler chickens.
• The use of CBP can reduce the requirement for inorganic P supplementation in poultry diets.