Birteeb Peter T, Peters Sunday Olusola, Yakubu Abdulmojeed, Adeleke Matthew Adekunle, Ozoje Michael Ohiokhuaobo
Department of Animal Science, University for Development Studies, P.O. Box TL 1882, Tamale, Ghana.
Trop Anim Health Prod. 2013 Jan;45(1):267-74. doi: 10.1007/s11250-012-0211-4. Epub 2012 Jun 19.
The characterisation 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 at morphological characterisation of the two main breeds of sheep in Ghana by assessing variation within and between breed populations using principal component and discriminant analyses. The two breeds were the Sahel and the Djallonke sheep of both sexes and of two groups namely, young (1 year old, consisting of 74 animals) and mature sheep (≥ 2 years old, comprising 219 animals). The analysis of variance revealed significant (P < 0.05) differences in the morphological traits of the Sahel and the Djallonke sheep breeds with higher values recorded for the former. Sexual dimorphism was in favour of male animals in all the morphological traits examined. Mature animals also had comparative advantage over the young. Two principal components were extracted 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 pin-bone width. Mahalanobis distance between the two genetic groups was 5.723 (P < 0.0001). The developed discriminant functions clearly discriminated and classified the Sahel and the Djallonke sheep into their breeds of origin, thus yielding 100, 93.4 and 90.4 % 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 Ghanaian sheep breeds.
发展中国家小型反刍动物种群的特征描述，对于维护遗传资源作为未来畜牧生产改良基础将发挥重要作用。本研究旨在通过主成分分析和判别分析评估加纳两个主要绵羊品种群体内部和群体之间的变异，从而对其进行形态特征描述。这两个品种是萨赫勒羊和贾隆克羊，涵盖了两个性别的两个年龄组，即幼年羊（1岁，共74只）和成年羊（≥2岁，共219只）。方差分析显示，萨赫勒羊和贾隆克羊品种在形态特征上存在显著（P < 0.05）差异，前者的各项数值更高。在所检查的所有形态特征中，两性异形均有利于雄性动物。成年羊也比幼年羊具有相对优势。提取了两个主成分以辨别这两个基因群体的结构。这两个绵羊品种之间最具区分性的特征是臀高、肩高、颈围和坐骨宽度。两个基因群体之间的马氏距离为5.723（P < 0.0001）。所建立的判别函数能够清晰地将萨赫勒羊和贾隆克羊区分并归类到它们各自的品种来源，对公羊、母羊和整个绵羊群体的准确分类率分别为100%、93.4%和90.4%。本方法将极大地有助于制定管理和保护政策，以实现加纳这两个绵羊品种的可持续生产。
