Study of genetic and non-genetic effects on cumulative survival in a crossbred population of quail.

Minimizing bird mortality in the commercial quail breeding industry is important from an economic and welfare perspective. Genetic and non-genetic factors can influence on the cumulative survival of the birds (CS). Accordingly, this study aimed to investigate non-genetic factors on CSs (cumulative survival of the birds from hatch to 5 (CS₁), 10 (CS₂), 15 (CS₃), 20 (CS₄), 25 (CS₅), 30 (CS₆), 35 (CS₇), 40 (CS₈), and 45 (CS₉) days of age), and estimation of the genetic parameters for CSs in crossbred population of quail. Data set included 1794 records from crossbred chicks hatched from 70 sires and 72 dams. The fixed effects were analyzed using an animal model by ASReml software, and all traits were analyzed using Bayesian method via Gibbs sampling by fitting of 6 threshold animal models including the direct genetic effect, the maternal permanent environmental effect, and the maternal genetic effect. The best fitted model for each trait was selected based on the deviance information criteria. Hatch number, the month of hatch, and combination of chickens showed a significant effect on CSs, but the sex of chickens does not have a significant effect on CSs. However, females have higher survival than males (except for CS₁). With the best model, the highest and lowest direct heritability was estimated for CS₅ (0.386) and CS₃ (0.250), respectively. The maternal genetic effect was significant for CS₁, CS₂, CS₃, and CS₄ traits, but the maternal permanent environmental effect was significant only for CS₁. The range of maternal heritability for CS₁ to CS₄ traits was estimated from 0.064 to 0.111, and ratio of the permanent environmental variance to phenotypic variance for CS₁ was 0.021. The result showed that increasing of the birds’ survival could be performed by correcting non-genetic factors and genetic selection for CSs considering the maternal genetic effects in younger ages. Highlights: • In the commercial quail breeding industry, the bird mortality is important from an economic and welfare perspective. • Improving quail survival can be achieved by controlling the genetic and non-genetic factors affecting on survival, so knowledge of these factors is necessary. • The combination of crossbred chickens had a significant effect on cumulative survival traits. • The Cumulative survival traits in the crossbred population had relatively high genetic diversity, so genetic selection for these traits could be effective. [ABSTRACT FROM AUTHOR]