Evolution of Population Structure, Reproductive Performance, Inbreeding, and Genetic Diversity in Ecuadorian...

Area of Science:

• Animal Genetics and Breeding
• Population Genetics
• Livestock Management

Background:

• Understanding population structure, reproductive performance, inbreeding, and genetic diversity is crucial for sustainable livestock breeding.
• The Charolais cattle breed in Ecuador has undergone changes in breeding practices, necessitating an evaluation of its genetic health.

Purpose of the Study:

• To assess the evolution of population structure, reproductive efficiency, inbreeding, and genetic diversity in Ecuadorian Charolais cattle.
• To analyze the impact of different mating periods and reproductive technologies on genetic parameters over time.

Main Methods:

• Utilized official genealogical data from the Ecuadorian Charolais Association, divided into five distinct population groups.
• Evaluated population structure using pedigree completeness and generation interval (GI).
• Estimated genetic diversity (GD), inbreeding (F), average relatedness (AR), and effective population size (Ne) using ENDOG, POPREP, and CFC software.

Main Results:

• Pedigree completeness and GI decreased over time, with a greater sire gametic pathway observed across all populations.
• Inbreeding (F) showed a slight increase, while effective population size (Ne) remained above recommended levels.
• Genetic diversity loss (GD) progressively increased, though female reproductive efficiency improved over the study period.

Conclusions:

• The generation interval (GI) in Charolais cattle requires reduction.
• Assisted reproductive technologies and breeding schemes implemented after 2012 accelerated genetic diversity loss.
• While inbreeding has increased, incorporating foreign genetic resources could mitigate this in the Ecuadorian Charolais population.