Interrelationship between environmental temperature and dietary nonphytate phosphorus in chicks

Area of Science:

• Animal Nutrition
• Poultry Science
• Environmental Physiology

Background:

• Dietary phosphorus is crucial for poultry growth and development.
• Nonphytate phosphorus (NPP) is the primary digestible form of phosphorus for poultry.
• Environmental temperature significantly impacts nutrient utilization and animal welfare.

Purpose of the Study:

• To investigate the effect of different nonphytate phosphorus (NPP) levels on chick growth at varying temperatures.
• To determine the impact of acute heat stress on chicks with different NPP dietary levels.
• To assess the potential interaction between NPP requirements and high ambient temperatures in young poultry.

Main Methods:

• Chicks (8-22 days old) were fed diets with varying NPP levels (0.2-0.5%) at constant temperatures (25°C and 37°C).
• Subsequent experiments involved exposing chicks to temperature changes to evaluate heat stress responses.
• Mortality and signs of heat distress were recorded under different dietary and environmental conditions.

Main Results:

• At 37°C, weight gain was limited at NPP levels above 0.3%, unlike at 25°C where all NPP levels supported increased weight gain.
• Chicks housed at 37°C showed reduced weight gain compared to those at 25°C for most NPP levels.
• Sudden exposure to 37°C in older chicks fed low NPP diets resulted in high mortality and severe heat distress.

Conclusions:

• The NPP requirement for growing chicks may be lower under high ambient temperatures.
• Inadequate NPP levels can exacerbate negative effects of heat stress, leading to increased mortality.
• Careful management of dietary NPP is essential, especially when anticipating environmental temperature fluctuations in poultry production.