Behavioural and physiological fear responses in ducks: genetic cross effects

Area of Science:

• Animal Behavior
• Genetics
• Poultry Science

Background:

• Mule ducks, a cross between Muscovy drakes and Pekin females, display pronounced fear behaviors like man avoidance.
• Previous research suggested a dominant Pekin genotype effect, but lacked reciprocal cross data to confirm additive vs. maternal effects.

Purpose of the Study:

• To investigate the genetic basis of fear responses in mule ducks and their reciprocal cross (hinnies).
• To differentiate between additive genetic effects, maternal effects, and heterosis in fear behavior.

Main Methods:

• Comparative analysis of fear responses in mule ducks, hinnies, Pekin ducks, and Muscovy ducks.
• Inclusion of physiological (basal adrenal activity) and individual behavioral tests.

Main Results:

• Both Pekin and Muscovy ducks showed high fear, but with distinct patterns (locomotor activity vs. man avoidance).
• Hybrids (mule ducks and hinnies) displayed significantly higher panic responses and specific fear of humans.
• Significant heterosis effects were observed for most fear behaviors and basal adrenal activity, with hybrids showing higher levels than parents.
• Pekin genotype showed superiority in additive effects for maximum adrenal response capacity.

Conclusions:

• Fear responses in mule ducks and hinnies are influenced by significant heterosis, resulting in heightened fear compared to parental breeds.
• Maternal effects were not significant in determining fear patterns in the hybrids.
• The Pekin genotype contributes additively to the maximum adrenal response capacity.