Inbreeding, Methods of Estimating Inbreeding Coefficients, Systems Measurement of Inbreeding | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Inbreeding and Estimating Inbreeding Coefficients

Introduction to Inbreeding:

• Inbreeding refers to the process of mating closely related individuals within a population.
• It leads to an increase in homozygosity, resulting in offspring with similar genetic material.

Concept of Inbreeding:

• When related individuals reproduce, their offspring tends to become more homozygous.
• This increase in homozygosity is due to the probability of both parents carrying the same gene.
• Selfing of individuals leads to a rapid increase in homozygosity, as seen in plants.

Calculating Inbreeding Coefficients:

• The inbreeding coefficient measures the decrease in heterozygous genes due to inbreeding.
• Formula for calculating inbreeding coefficient:
  • Fx = 1/2 * [(1/2) ^ (1 - F)]
  • Where Fx is the inbreeding coefficient of individual X and F is the inbreeding coefficient of the common ancestor.
• If the common ancestor is not inbred, the formula simplifies to Fx = 1/2 * [(1/2) ^ path length].

Effects of Inbreeding:

• Inbreeding leads to a gradual increase in homozygosity in animal populations.
• Unlike self-fertilization in plants, inbreeding in animals is slower due to less intense mating patterns.
• Even with full brother-sister matings, the increase in homozygosity is relatively slower than in plants.

Inbreeding Coefficients Calculation

• When calculating inbreeding coefficients for various types of matings with a common inbred ancestor, a shorter formula is utilized.

• For instance, if two individuals share an inbred ancestor, the inbreeding coefficient can be computed using the shorter formula.

• Calculating inbreeding coefficients involves utilizing a concise formula for matings with inbred common ancestors.
• The shorter formula simplifies the process of determining inbreeding coefficients in specific scenarios.