Repeatability of a Trait: Properties

Correct Answer: All of the Above

From Table 12 (Differences between Heritability and Repeatability) in the notes:

• (a) Predicts future from past performance: Repeatability = regression of future performance on present performance.
• (b) Upper limit of heritability: Repeatability ≥ Heritability always. So if repeatability = 0.35, then heritability CANNOT be 0.40 (which is greater than repeatability).
• (c) Used for culling decisions: MPPA (Most Probable Producing Ability) / ERPA (Expected Real Producing Ability) is estimated using repeatability and is the best predictor of an animal's producing ability.

Formula (from notes)

r = (VG + EP) / VP, where EP = permanent component of environment. Range of repeatability: 0 to +1.

Sample Question (from notes)

If repeatability = 0.30, the value 0.45 is NOT possible for heritability — because heritability cannot exceed repeatability.