Analyse procrustéenne généralisée de la forme du bec chez deux génotypes de poulet local, Cou nu et normalement emplumé

Abstract

This work has allowed us to demonstrate that the geometric MG morphometry can be practiced to answer our questions, it is a powerful tool allowing to identify and visualize the changes of the conformations of the beaks. Modern techniques of morphometry are based on the configuration of landmarks or landmarks that we have employed in a 2D frame; via the procruste overlay on scanned images of the upper side nozzles, which allowed us to synthesize, at the desired precisionpy scale, the geometry of an object. geometric morphometry has an exact and rigorous mathematical foundation that guarantees robust statistics. The objective is therefore to study and quantify the variability in beak shapes (conformations + centroid sizes) of the 2 genotypes of normal local chicken and local bare neck chicken, a total of 61 local normal chickens and 20 local bare neck chickens. Principal component analysis (PCA) allowed us to extract 4 significant principal components explaining about 85% of the total variation in the shape of the beak, hence the permutation test, the Mahalanobis distance and that of procruste demonstrated a very significant difference (P 0,0001) between the two strains ˂ naked neck and normally feathered by the shape of the beak. Therefore the landmarks method applied here via procrustean analysis has been shown to be extremely efficient and accurate in identifying and visualizing beak conformations in chickens. Finally, we can say that our results reveal the great interest of MG in the study, on the one hand, we have confirmed the hypothesis of the variability between the beaks of the two strains, and on the other hand, it has us encouraged to continue studying to find a radical solution to the problem at hand.