Effectiveness of Progeny Testing & Family Selection

Progeny testing & family selection are more effective when heritability of a trait is-

Correct Answer: Low

Progeny testing and Family selection are most effective when the heritability of a trait is low. When h² is low, an individual's own phenotype is a poor indicator of its breeding value (environment overwhelms genetics). By using many progeny or family members, environmental noise is averaged out.

Why Low h² Favours These Methods

• h²N = VA/VP: if VP is large relative to VA (low h²), individual phenotype is unreliable.
• Progeny testing averages across many daughters → environmental deviations cancel out → accurate BV estimate.
• Family selection uses the mean of the family → more reliable than a single animal's record.

Practical Application

• Reproductive traits (low h² ~0.05–0.15): evaluated by progeny testing and family selection.
• Productive traits (medium h²): combination of methods.
• Growth/quality traits (high h² ~0.4–0.6): individual selection is sufficient.