Genetic Evaluation and Trends of Japanese quail Data Selected for 4-wk Body Weight

The present study aimed to estimate the genetic parameters and evaluate the genetics trend of body weight traits and right shank length of Japanese quail data selected two generation for 4-wk body weight. Body weights heritability (h 2 ) estimates ranged from moderate to high and revealed that selection in HL individuals is probably more efficient at later ages. For shank length, heritability values found to be relatively high and individual selection may apply early in quails' life. Genetic correlations between body weight traits were high, while the correlation between body weight and shank length was found to be moderate and mostly insignificant. Body weight of the tested quail population have positive genetic trend only at 4 wks of age, whilst for the other body weight (non-selected for traits) tend to be negative. Estimated genetic trend also found to be higher in the second generation from the 4 th wk of age onwards while the reverse was true in the era before. This may mean that birds tend to get better improvement at later ages of life on the expense of that at earlier ages.