Genetic variation in packed cell volume associated with variations in response to cold temperature

Area of Science:

• Animal Science
• Poultry Genetics
• Environmental Physiology

Background:

• Environmental temperature significantly impacts poultry physiology and performance.
• Packed red blood cell volume (PCV) is an indicator of physiological status in birds.
• Understanding heritability is crucial for selective breeding programs in poultry.

Purpose of the Study:

• To compare the heritability of packed red blood cell volume (PCV) in broiler chicks.
• To investigate the correlation between PCV and growth gain under different brooding temperatures.
• To assess the influence of cold (26.7 C) versus normal (32.2 C) environmental temperatures on PCV and growth.

Main Methods:

• Progeny from 28 sire families were brooded under two distinct environmental temperatures: 26.7 C (cold) and 32.2 C (normal).
• Packed red blood cell volume (PCV) was measured for all chicks.
• Heritability estimates for PCV and correlations with growth gain were calculated for each temperature group.

Main Results:

• Chicks brooded at 26.7 C exhibited a higher average PCV (32.7%) compared to those at 32.2 C (30.9%).
• Heritability estimates for PCV were .51 in the cold group and .57 in the normal temperature group.
• No significant differences in growth gain were observed between the temperature groups, and PCV was not correlated with gain.

Conclusions:

• Environmental temperature influences PCV in broiler chicks, with colder conditions leading to higher values.
• Heritability of PCV remains substantial across the tested temperature ranges.
• PCV does not appear to be a limiting factor for growth gain under these experimental conditions, irrespective of temperature.