Understanding Heritability Estimates in Swine

Introduction: Heritability estimates play a crucial role in livestock breeding by measuring the genetic influence on specific traits. This summary focuses on heritability estimates for swine, helping producers understand and utilize these estimates to improve their breeding programs.

What is Heritability? Heritability measures the proportion of total trait variation due to genetic differences among animals. It is expressed as a ratio of genetic variance to total variance, with values ranging between 0 and 1. Higher heritability indicates a greater genetic influence on the trait.

Heritability Estimates for Swine: Here are some key heritability estimates for swine traits:

Reproduction Traits:

  • Number farrowed: 0.10
  • Number weaned: 0.10

Growth Traits:

  • Birth weight: 0.10
  • Weaning weight: 0.15
  • Growth rate: 0.30

Efficiency Traits:

  • Feed efficiency: 0.35

Carcass Traits:

  • Meat tenderness: 0.30
  • Meat color: 0.30
  • Marbling (in loin): 0.30
  • Meat firmness: 0.30
  • Backfat thickness: 0.50
  • Loineye area: 0.50
  • Length: 0.60
  • Percent ham, chilled carcass weight: 0.60
  • Percent fat cuts, chilled carcass weight: 0.60
  • Percent lean cuts, chilled carcass weight: 0.50

Calculation and Usefulness: Heritability estimates are calculated by comparing the performance of related animals. The commonly used method is the paternal half-sib analysis of variance. These estimates guide producers in selecting superior animals for breeding, estimating genetic progress, and choosing appropriate evaluation methods.

Impact of Heritability on Selection: High heritability traits (above 0.30) allow for effective selection based on individual performance. For low heritability traits, using related animals’ performance or outbreeding systems to exploit hybrid vigor can be beneficial.

Conclusion: Understanding and utilizing heritability estimates enables swine producers to make informed breeding decisions, ultimately enhancing productivity and genetic improvement in their herds. By focusing on traits with higher heritability, producers can achieve more significant progress in their breeding programs.