Seasonal acclimatisation in the hen

Area of Science:

• Animal Physiology
• Environmental Biology
• Poultry Science

Background:

• Laying hens exhibit physiological adaptations to varying environmental conditions.
• Understanding thermoregulation is vital for optimizing poultry health and productivity.

Purpose of the Study:

• To investigate the seasonal impact on the thermoneutral zone and oxygen consumption of laying hens.
• To determine the relationship between ambient temperature, critical temperature, and metabolic rate in poultry.

Main Methods:

• Measurements of oxygen consumption and body temperature in White Leghorn x Rhode Island Red hens.
• Controlled environmental chamber experiments across a temperature range of 2-32°C.
• Correlation analysis between seasonal temperature shifts and physiological parameters.

Main Results:

• A significant seasonal variation was observed in lower critical temperature and thermoneutral oxygen consumption.
• The slope of oxygen consumption versus air temperature below the critical temperature remained unaffected by season.
• A 10°C decrease in mean daily outside temperature correlated with an 8.5°C decrease in critical temperature and a 12% increase in oxygen consumption.
• Heat acclimatization enhanced the hens' ability to maintain body temperature stability.

Conclusions:

• Poultry exhibit seasonal acclimatization in thermoregulatory responses.
• Environmental temperature significantly influences the metabolic rate and thermal critical points in laying hens.
• Heat acclimatization is a key factor in improving poultry resilience to thermal extremes.