Morphology Differentiation and Structural Functionality of Ewes Due to Incomplete Crossbreeding Diferenciación Morfológica y Funcionalidad Estructural de Ovejas Debido a Cruzamiento Incompleto

R. de la BarraLATORRE, E.; URIBE, H.; MARTINEZ, M. E.; CALDERON, C. & DE LA BARRA, R. Morphology differentiation and structuralfunctionality of ewes due to uncomplete crossbreeding. Int. J. Morphol., 29(3):954-959, 2011.SUMMARY: Most Chilean sheep stock comprises different degrees of crossbreeding over Corriedale breed. A common absorbentcrossbreeding has been Australian Merino over Corriedale which, in many cases, has not been complete. The aim of this study was toevaluate the process of morphology differentiation and structural functionality of Corriedale ewes undergoing incomplete absorbentcrossbreeding which was carried out in order to create an animal with a new morphology. A total of four hundred adult ewes weremeasured; two hundred belonging to the incomplete crossbreeding, and two hundred from the two original breeds (one hundred Corr iedaleand one hundred Australian Merino ewes). All measured ewes were randomly selected. Fourteen body measurements were recorded andnine body indexes were calculated for each ewe. Results show that a new biotype has been created from the absorbent crossbreedi ng ofCorriedale by Australian Merino, which produced ewes with a clear morphological and structural functionality differentiation as comparedto the two original breeds. The new body format shows morphostructural variability coefficients that are similar to those found on otherformally recognized sheep breeds.KEY WORDS: Sheep; Breeding; Morphology.