Path analysis of body weight and morphometric traits of Nigerian indigenous Muscovy ducks

Body weight and seven biometric traits namely, body length, breast circumference, thigh circumference, bill length, neck length, foot length and wing length of 221 adult Nigerian Muscovy ducks were subjected to path analysis. The ducks, reared under the traditional scavenging system, were randomly selected in Nasarawa State, north central Nigeria. The investigation aimed at determining the explanatory variables that most effectively influenced the body weight of indigenous ducks of both sexes. Sex-associated differences (P<0.05) were observed in all the studied traits, with superior values recorded for males (drakes). Bivariate correlations between body weight and linear body measurements in drakes ranged from 0.743-0.919. Correspondingly, a range of 0.745- 0.894 was obtained in female ducks. The path analysis revealed that thigh circumference had the strongest direct effect on body weight of drakes, followed by body length, wing length and foot length (path coefficient = 0.326, 0.312, 0.286 and 0.115 respectively). However, a different trend was observed in females, where the influence of wing length on body weight was greatest, followed by thigh circumference, bill length and foot length (path coefficient = 0.340, 0.289, 0.217 and 0.171, respectively). The optimum linear multiple regression model in drakes included forecast indices such as thigh circumference, body length, wing length and foot length, with a determination coefficient (R2) of 0.962 and determination coefficient of error of 0.038. The corresponding indices in female ducks were wing length, thigh circumference, bill length and foot length with R2 value of 0.917 and determination coefficient of error of 0.083. These models could be useful in weight estimation in the field and for selection purposes.