Rectovaginal constriction in Jersey cattle: genetics and breed dynamics

Area of Science:

• Animal genetics
• Population genetics
• Veterinary science

Background:

• Rectovaginal constriction is a genetic disorder observed in US Jersey cattle.
• Previous studies suggested monofactorial recessive inheritance.
• Understanding the genetic dynamics is crucial for breed management.

Purpose of the Study:

• To confirm the inheritance pattern of rectovaginal constriction.
• To model the genetic dynamics and predict gene frequency changes.
• To inform selection strategies in Jersey cattle populations.

Main Methods:

• Analysis of data from farmer-owned herds and experimental matings.
• Extension of Kempthorne's population genetics model to include mutation and female selection.
• Computer simulations to estimate gene frequency decline over generations.

Main Results:

• Monofactorial recessive inheritance of rectovaginal constriction was supported.
• The extended population genetics model estimated a slow decline in gene frequency.
• Simulations provided projections for current and future conditions over 500 generations.

Conclusions:

• Rectovaginal constriction is a heritable trait in Jersey cattle.
• Female selection is predicted to slowly reduce the prevalence of the causative gene.
• The findings offer insights for managing genetic disorders in livestock breeds.