Exploratory transcriptomic analysis in muscle tissue of broilers fed a phytase-supplemented diet.

Area of Science:

• Animal Nutrition
• Biochemistry
• Genomics

Background:

• Phytase is known to improve phosphorus retention and broiler performance.
• Extra-phosphoric effects of phytase, including impacts on mineral and amino acid metabolism, are recognized.
• The specific role of myo-inositol in phytase responses requires further elucidation.

Purpose of the Study:

• To investigate the effects of microbial phytase on broiler growth, nutrient digestibility, blood biochemistry, and gene expression.
• To explore the potential role of myo-inositol in phytase-mediated responses in broilers.
• To understand the molecular mechanisms underlying phytase's impact on broiler muscle development.

Main Methods:

• A 5-week broiler floor pen trial using a moderately phosphorus-deficient diet supplemented with 1000 U/kg of microbial phytase.
• Measurement of growth performance, plasma phosphorus, calcium, and myo-inositol concentrations, apparent ileal phosphorus digestibility, and tibia ash content.
• Transcriptomic analysis of the Pectoralis major muscle, with validation of key differentially expressed genes using quantitative PCR (qPCR).

Main Results:

• Phytase supplementation significantly improved broiler weight gain (18% starter, 24% whole period) and feed conversion ratio.
• Increased plasma myo-inositol concentration, tibia ash content, and breast meat weight were observed in broilers fed phytase.
• Transcriptomic analysis identified differentially expressed genes in pathways related to muscle development, including calmodulin/calcineurin and insulin-like growth factor signaling.

Conclusions:

• Dietary phytase supplementation enhances broiler performance and bone mineralization.
• Phytase may indirectly generate myo-inositol, influencing broiler metabolism.
• Gene expression analysis reveals phytase's role in modulating muscle development pathways, providing molecular insights into its benefits.