Estimates of genetic parameters for body weights at late growth period and humoral ‎immunity in Japanese quail

The aim of the current study was to estimate the genetic parameters of growth traits at the late ages (25-45 days of old) as well as humoral immune responses in Japanese quail. Therefore, the studied traits were growth traits (body weights (BW) at 25, 30, 35, 40 and 45 days of age, average daily gain (ADG) in 5 day periods as well as the immune system responses against SRBC (IgT) and Newcastle vaccine (IgN)). To estimate genetic parameters, a multivariate analysis was utilized using Gibbs sampling through Gibbsf90 software. The heritability for BW and ADG were varied between 0.303-0.437 and 0.053-0.338, respectively. Moreover, heritability estimates for IgT and IgN were 0.252 and 0.015, respectively. Genetic correlation between growth traits with immune responses were negative and ranged from low to moderate (−0.218 to −0.483). According to the results, genetic selection based on BWs might to result in higher genetic response than ADG and immune system performances. Among body weight traits, the BW30 based on its higher genetic correlation with BW45 (0.809), moderate heritability (0.406) and negative and relatively low genetic correlation with IgT (−0.226) and IgN (−0.235) would be consider as an appropriate criterion introduce applicable breeding program to improve growth traits with lower decreasing in the immune system performance.