استخدام تحليل التباين المتعدد في توصيف الصفات الجسمية لأغنام العرابي و العواسي في القطعان التجارية

الملخص EN

The characterization of the small ruminant populations in developing countries will play a major role in the maintenance of the genetic resources as the basis for future improvement in livestock production.

The present study aimed to use the multivariate analysis in description the morphological characterization of the two main breeds of sheep in Iraq by assessing variation within and between breed populations using principal component and discriminant analyses.

The Arabi and Awassi sheep of both sexes and of groups namely, young (1 year old, consisting of 100 animals) and mature sheep (≥2 years old, comprising 184 animals).

The analysis of variance revealed significant (P<0.05) differences in the morphological traits of the Awassi and the Arabi sheep breeds with higher values recorded for the former.Sexual dimorphism was in favor of male animals in all the morphological traits examined.

Mature animals also had comparative advantage over the young.

Two principal components were found to discern the structure of the two genetic groups.

The most discriminating traits between the two sheep breeds were rump height, height at withers, neck girth and pinbone width.

Mahalanobis distance between the two genetic groups was 6.793 (P<0.0001).

The developed discriminant functions clearly discriminated and classified the Awassi and the Arabi sheep into their breeds of origin, thus yielding 100, 95.6 and 92.5 % accurate classification for the rams, ewes and the overall sheep population, respectively.

The present approach would greatly help in establishing management and conservation policies for the sustainable production of the two Iraqi sheep breeds.