Reproductive Performance, Inbreeding, and Genetic Diversity in Montbeliarde Dairy Cattle Obtained by Absorption...

Area of Science:

• Animal Science
• Genetics
• Reproductive Biology

Background:

• Montbeliarde dairy cattle were introduced to Ecuador to improve existing breeds.
• Absorption crossing was used to integrate Montbeliarde genetics.

Purpose of the Study:

• To analyze the reproductive performance, demographic structure, inbreeding, and genetic diversity of Ecuadorian Montbeliarde cattle.
• To assess the impact of absorption crossing on the breed's genetic health.

Main Methods:

• Utilized official pedigree records from the Ecuadorian Montbeliarde Association.
• Analyzed demographic variables (e.g., pedigree completeness index, generation interval).
• Evaluated inbreeding metrics (e.g., inbreeding coefficient, effective population size) and genetic diversity indicators (e.g., number of founders, genetic diversity loss).
• Employed ENDOG, POPREP, and CPC software for database analysis.

Main Results:

• Pedigree completeness decreased, while dam reproductive efficiency increased over time.
• Inbreeding coefficient (F) reached approximately 1%, with an inbreeding increment (ΔF) of 0.22%.
• Effective population size (Ne) was 58, indicating a decline.
• Genetic diversity loss was observed due to unequal founder contributions and genetic drift.

Conclusions:

• The Ecuadorian Montbeliarde cattle population exhibits low genetic diversity and high relatedness.
• Inbreeding levels are rising, and effective population size is shrinking.
• Introducing new purebred bloodlines is crucial for long-term conservation and mitigating genetic diversity loss.