Gender differences for growth in North American Atlantic salmon

Area of Science:

• Aquaculture
• Genetics
• Animal Breeding

Background:

• Aquaculture of Atlantic salmon assumes perfect genetic correlation between male and female growth.
• This assumption implies families would rank similarly based on either sex's growth.
• Previous studies suggest potential differences in genetic linkage maps between male and female salmon.

Purpose of the Study:

• To investigate the genetic correlation of growth traits between male and female Atlantic salmon.
• To determine if gender dimorphism exists in growth within families.
• To challenge the assumption of identical genetic control over male and female growth in aquaculture.

Main Methods:

• Applied a multiple trait family model to weight and length data at 3 years of age.
• Utilized data from North American Atlantic salmon at Oak Bay Hatchery, New Brunswick, Canada.
• Estimated genetic correlations using Bayesian methods.

Main Results:

• Genetic correlations between male and female growth in freshwater and seawater were estimated.
• The estimates indicated potential differences in growth traits based on gender.
• Findings suggest that male and female growth may be separate traits.

Conclusions:

• The study supports the existence of gender dimorphism in growth traits for North American Atlantic salmon.
• This finding has implications for selective breeding programs in salmon aquaculture.
• Rethinking the assumption of perfect genetic correlation between sexes is recommended for improved breeding strategies.