Cyclic changes in serum phosphorus of laying hens

Area of Science:

• Animal Science
• Poultry Science
• Biochemistry

Background:

• Serum phosphorus is a critical mineral for laying hens, influencing eggshell quality and bone health.
• Understanding the diurnal fluctuations of serum phosphorus is essential for optimizing poultry nutrition and management.

Purpose of the Study:

• To investigate the 24-hour changes in serum phosphorus levels in laying hens.
• To correlate these changes with physiological processes such as egg formation and bone metabolism.

Main Methods:

• Three trials were conducted involving 63-week-old laying hens that met specific egg-laying criteria.
• Blood samples were collected via heart puncture at various time points over a 24-hour cycle.
• Serum phosphorus was analyzed colorimetrically after deproteinization.

Main Results:

• Serum phosphorus levels peaked at 6.08 mg.% around 7 a.m.
• A significant drop to 4.88 mg.% was observed by 8 a.m., remaining stable until noon.
• Levels gradually increased from 5.29 mg.% to 5.80 mg.% between 2 p.m. and 6 a.m.

Conclusions:

• Diurnal variations in serum phosphorus are evident in laying hens.
• These fluctuations are associated with eggshell calcification, bone resorption and remineralization, and renal clearance processes.