Characterization of poultry egg production using a multiphasic approach.

Area of Science:

• Animal Science
• Chronobiology
• Poultry Science

Background:

• Individual hen egg production is complex, influenced by clutch size, internal laying, and pauses between clutches.
• Circadian rhythms, comprising daily rhythms and lag, regulate clutch formation.
• Internal laying and pauses (delay) are influenced by genetic and environmental factors, respectively.

Purpose of the Study:

• To develop and apply a multiphasic model to characterize egg production in hens.
• To quantify parameters of lag and delay in egg production using a novel modeling approach.
• To investigate the genetic and environmental influences on egg production phases.

Main Methods:

• A multiphasic model was developed to describe cumulative egg number over time, incorporating lag and delay.
• Data were adjusted for internal laying and pauses before analysis.
• An inverse function was used to estimate average lag and delay from hourly data of four hens over 16 days.

Main Results:

• Lag parameters ranged from -0.08 to 2.11 hours.
• Lag was positively correlated with clutch number and negatively with average clutch length and total eggs.
• Average delay was approximately 16 hours, potentially influenced by the light:dark ratio.

Conclusions:

• The multiphasic model effectively characterizes hen egg production by quantifying lag and delay.
• Lag and delay parameters provide insights into the genetic and environmental regulation of egg-laying cycles.
• Findings suggest photoperiod significantly influences the delay component of egg production pauses.