Meta-Analysis of Genetic Parameters for Growth and Carcass Traits in Japanese Quail

The considerable variability observed in genetic parameters for growth and carcass traits in Japanese quails necessitates a meta-analysis for their accurate estimation. Such a precise estimation is crucial for the successful optimisation of breeding programs.

This pioneering comprehensive systematic review and meta-analysis aimed to derive precise genetic parameters for growth and carcass traits in Japanese quail.

For this meta-analysis, data were systematically extracted from 50 eligible studies published between 1974-2024. Genetic parameters including, heritability, genetic and phenotypic correlations for body weight at different ages and carcass traits, were estimated using random-effects models within metafor package.

Meta-analysis results showed that hatch weight had the highest heritability estimate (0.38 ± 0.003). Weekly body weights (W₁-W₆) demonstrated heritability estimates ranging from 0.23 to 0.30. Genetic correlations among body weights at different ages were consistently positive and strong, particularly between consecutive ages, whereas phenotypic correlations were comparatively weaker. The study found moderate to high heritability estimates (0.24 to 0.33) for carcass traits. Furthermore, positive genetic correlation was observed between slaughter and carcass weight (0.96 ± 0.07). Similar patterns were noted for other carcass traits, like breast weight and thigh weight. However, genetic correlation between slaughter weight and abdominal fat weight was notably lower. The heterogeneity index (I²) was over 90% for most estimates.

The findings demonstrate that selecting for increased body weight can improve carcass yield without promoting excessive adiposity. This study provides reliable genetic parameters to develop quail breeding programs for enhanced productivity and meat quality.