No abstract

Understanding morphological structure and variation of Zulu sheep is crucial for its identification and preservation. We measured fourteen linear body measurements and scored 5 qualitative traits to evaluate the morphological variation and relationships among eight Zulu sheep populations in KwaZulu-Natal. Sheep were sampled from Empangeni, Escourt, Eshowe, Jozini, Msinga, Mtubatuba, Nongoma, and Nquthu rural communities. Dark brown coat colour, either in solid form or white patched, was most frequent amongst studied sheep. There were significant variations in body measurements amongst sheep populations from different areas. Sheep from Nqutu measured highest in most morphometric variables while sheep from Empangeni measured lowest. Discriminant analysis identified rump-width, head-width, heart-girth, thorax-depth and tail-length as the most distinguishing variables amongst sheep populations. Hierarchical cluster analysis revealed two major groups, one formed by Empangeni, Mtubatuba and Nongoma, the other by Jozini, Msinga and Eshowe populations. Estcourt and Nqutu distanced themselves from these groups as individual entities. About 62% of individual sheep could be correctly identified with the populations from which they were sampled. Nqutu had the highest percentage (88.9%) of correct assignment whilst Mtubatuba had the lowest (46.7%). High assignment errors were ascribed to a certain gene flow between sheep populations. The overall significant morphostructural variation amongst Zulu sheep populations, infers considerable genetic variability within the breed and its populations. Maintaining this genetic variation is very crucial for the continuity of the breed, as it provides animals with options to respond to change in climate, disease or consumer preference.

This study was conducted to investigate phenotypic and genetic differentiation among the four Nguni sheep breeds. Sheep with two permanent incisors and above were sampled from areas, namely KwaZulu-Natal (Zulu sheep), Limpopo (Pedi sheep), Mozambique (Landim sheep) and Swaziland (Swazi sheep). The Dorper was used as an out-group. Eight morphometric variables were measured from each animal, and blood samples were collected (n = 50 per population) for genetic characterization. The mean body weights for sheep were 30.41 ± 0.41, 35.34 ± 0.43, 35.23 ± 0.43, 37.63 ± 0.42 and 52.84 ± 0.30 for Swazi, Zulu, Landim, Pedi and Dorper, respectively. Morphometric cluster analysis showed the Landim, Swazi and Zulu breeds in one cluster. The Pedi sheep were closer to the Dorper than to the other Nguni sheep. Random amplified polymorphic DNA (RAPD) technique was used to assess genetic variation. Eight primers were selected for analysis based on band pattern quality, reproducibility and the presence of distinctive bands. The Swazi sheep formed a cluster with Zulu sheep, and the Pedi formed a cluster with the Dorper. These results confirm indications by other researchers that Pedi sheep are genetically distant from Zulu and Swazi sheep breeds. This could indicate the possibility of cross breeding Zulu and Swazi sheep as a possible conservation strategy to control inbreeding. The mtDNA should be analyzed to trace the relationships between Pedi and the three Nguni sheep breeds through maternal lines.