Data from 563 Pradu Hang Dum hens over two generations separated growth, maturity, egg output and laying persistency. Genetic correlations between egg number and persistency were strongly negative (-0.70 to -0.88), revealing a breeding trade-off.
Key findings
- Four components explained 71.7% of variance. Heritability was 0.72 for birth weight, 0.47 for weight at first egg, 0.43 for persistency and 0.08-0.12 for cumulative egg number. VIP DD and DRD2 CC had higher egg-number EBVs; NPY SS and MTNR1C AA had lower values.
Why this matters globally
Heat-adapted indigenous chickens are valuable for sustainable tropical food systems; multi-trait selection may improve long-term output while conserving genetic resources.
Thai researcher contribution
Thai researchers generated longitudinal Pradu Hang Dum data and combined quantitative genetics with candidate markers for tropical breeding strategy.
Limitations to consider
Only two generations of one breed were studied. Candidate-gene tests face multiple-testing and linkage concerns, showed no direct persistency association and require independent validation before marker-assisted selection.