Análisis multivariante de caracteres morfológicos de patos Muscovy Nigerianos (Cairina moschata)

摘要

This study was designed to investigate the possibility of classifying Nigerian Muscovy ducks into distinct ecotypes using stepwise discriminant analysis and Euclidean distance. Data were collected on ten morphological traits (body weight, body length, body girth, wing length, shank length, shank circumference, thigh length, total leg length, bill length and bill width) of one thousand and twenty (1020) adult Muscovy ducks comprising 203, 598 and 289 randomly sampled ducks from the rain forest, derived savanna and Guinea savanna ecotypes, respectively. The results of the descriptive statistics revealed highly (p<0.001) significant effects of ecotype on eight of the morphological traits except bill width and body length. Stepwise discriminant analysis indicated that bill length and body length had highest discriminating powers among the six distinguishing variables. Result of the cross validation of the correct assignment of ducks into distinct ecotypes was low; 53.7, 41.8 and 42.3 % of samples drawn from the rain forest, derived savanna and Guinea savanna ecotypes were correctly classified into their expected ecotypes. Euclidean distance between ecotypes was small; shortest distance was between rain forest and derived savanna ducks (2010) while the longest distance (3758) was between rain forest and Guinea savanna ducks. It is evident that due to the low classification success rate of discriminant analysis and short Euclidean genetic distance between ecotypes, they could not be classified into distinct ecotypes on the bases of morphostructural traits and appre-ciable heterosis is practically impossible from crossing Nigerian Muscovy ducks originating from different ecotypes.