Genetic parameters of production traits for Debrecen White Rabbit

The Debrecen White rabbit is a medium-sized breed highly suited for intensive meat production. To evaluate its genetic potential, our study analysed 18,885 production records from 2019 to 2025. The research focused on three primary growth traits: weight at 6 weeks, weight at 10 weeks, and average daily weight gain during the four-week fattening period. The rabbits averaged 1.17 kg at 6 weeks and more than doubled their mass to 2.50 kg by 10 weeks. The average daily weight gain reached 47.42 g, comfortably exceeding the standard 40 g benchmark for high-yielding strains. Growth parameters were significantly influenced by birth year, birth month and sex. While no sexual dimorphism was present at 6 weeks, males became significantly heavier than females by week 10 due to superior daily weight gains. Seasonality also played a major role; rabbits born in March achieved peak performance compared to autumn cohorts. Interestingly, annual data highlighted a compensatory growth mechanism, where cohorts entering the fattening period with lower 6-week weights achieved the highest daily gains to catch up by week 10. Heritability estimates were remarkably low, ranging from 0.02 to 0.08. This suggests that phenotypic variation is heavily dominated by environmental factors and maternal influences rather than additive genetics, likely due to decades of intense selection within a closed population. These near-zero heritabilities make direct mass selection highly inefficient, so transition to family-based BLUP models, genomic selection, or crossbreeding schemes to achieve further genetic progress might be favourable.