Path Analysis of the Relationships Between Various Body Measures and Live Weight of American Bronze Turkeys Under Three Different Lighting Programs

In animal breeding and genetics, knowledge of causal effects may provide valuable information on selection. Different contributions of explanatory variables to the traits indicate that the breeder has to choose the variable with the largest contribution in a selection effort. In this study, direct and indirect effects of four explanatory variables (Shank Length, Breast Length, Breast Depth and Breast Circumference) influential on live weight at week 30 in American Bronze turkeys were investigated using path analysis. Results of the analyses indicated that the direct effects of shank length were the largest on live weight. In general, indirect effects of Breast Length and Breast Circumference through Shank Length were highest among all indirect effects. Shank Length is the most influential variable and must be included in the model in estimating the live weight at week 30.