Thesis (PhD(Agric))--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This study set out to determine (co)variance components for the important production, reproduction and conformation traits of a South African fine wool resource flock that was established at the request of the South African wool industry. A secondary aim was to assess progeny of these animals under pastoral conditions in areas where the production of fine wool is uncommon. The Cradock fine wool Merino stud was established in 1988 with ewes bought from producers with the finest clips in South Africa. Data collected from 1988 to 2010 were used to estimate the (co)variances for the genetic fine wool resource flock. The quantification of the interdependencies of fibre diameter (FD) with production, reproduction and subjective traits were the main objective of this study. It is evident from the results of this study that FD is a highly heritable (0.63 ± 0.03) trait, which can lead to marked genetic progress provided that there are adequate levels of phenotypic variation available during selection. Fibre diameter was unfavourably correlated with body weight (0.30 ± 0.05), clean fleece weight (0.24 ± 0.05) and reproduction (0.59 ± 0.18), which implies that selection for reduced FD can have a detrimental effect on all these traits. Despite these unfavourable genetic correlations genetic gain in the other economical important traits was achievable in the stud (-0.129 ± 0.033). These results were supported by the results obtained during the evaluation of progeny of this stud under pastoral conditions where the production and reproduction of the fine wool animals were comparable with medium wool animals. It can therefore be concluded that selection for reduced FD can be practiced without detrimental effects on the economically important traits and subsequently the profitability of the sheep enterprise, as long as breeders have a reasonable selection objective based on economic considerations. / AFRIKAANSE OPSOMMING: Hierdie studie het dit ten doel gehad om (ko)variansie komponente vir die belangrike produksie, reproduksie en subjektiewe eienskappe in 'n Suid-Afrikaanse fyn wol hulpbronkudde, wat gevestig is op versoek van die Suid-Afrikaanse wolbedryf te bepaal. 'n Sekondêre doel was om die nageslag van hierdie diere onder veldtoestande te evalueer in gebiede waar die produksie van fynwol ongewoon is. Die Cradock fynwol Merino stoet is in 1988 gestig met die aankoop van ooie van produsente met die fynste skeersels in Suid-Afrika. Data wat ingesamel is vanaf 1988 tot 2010 is gebruik in die bepaling van (ko)variansie komponente vir hierdie genetiese fynwolkudde. Die kwatifisering van die interafhanklikheid van veseldikte (VD) met produksie, reproduksie en subjektiewe eienskappe was die hoofdoel van die studie. Dit is duidelik uit die resultate van die studie dat VD `n hoogs oorerflike (0.63 ± 0.03) eienskap is, wat tot vinnige vordering in VD kan lei indien genoegsame fenotipiese variasie beskikbaar is tydens seleksie. Veseldikte is ongunstig gekorreleer met liggaamsgewig (0.30 ± 0.05), skoonvaggewig (0.24 ± 0.05) en reproduksie (0.59 ± 0.18), wat beteken dat seleksie vir ʼn verlaagde VD nadelige vordering in hierdie eienskappe tot gevolg kan hê. Ten spyte van hierdie ongunstige genetiese korrelasies was die genetiese vordering in die ekonomies belangrike eienskappe haalbaar in die kudde wat ondersoek is (- 0.129 ± 0.033). Die laasgenoemde resultate word ondersteun deur die bevindinge dat die nageslag van hierdie stoet se produksie en reproduksie ooreengestem het met medium wol diere onder veldtoestande. Die gevolgtrekking wat gemaak kan word uit die studie is dat VD verlaag kan word sonder nadelige gevolge in die ekonomies belangrike eienskappe, asook die van `n skaapboerdery onderneming. Om dit te vermag moet telers `n aanvaarbare benadering tot seleksie, gegrond op ekonomiese beginsels, volg.

The Overberg, incorporating the present-day districts of Swellendam, Caledon and Bredasdorp, forms a geographic microcosm in the south-western Cape. The area, with its Mediterranean climate and undulating hills of Bokkeveld shales and weathered Table Mountain Sandstone, is well adapted for arable and pastoral agriculture. Original settlement was by the Khoi who by 1710 had succumbed to cumulative disintegrative forces. They presented little resistance to the vanguard of white settlers who by 1710 were receiving land grants in the area. By 1838 the area was optimally settled for the extensive ranching of that time and pressure on the land was becoming acute. There was little scope for British immigrants to obtain land among the Dutch settlers. Grain farming offered little reward as the area was isolated from the Cape Town market by hazardous mountain ranges. The conversion of the indigenous hairy sheep to wool-bearing Merinos which occurred during the 1830s provided the area with an added income. Wool provided a product which modified Overberg agriculture from its quasi-subsistence form to commercial farming. The wool produced in the area was generally of a high quality and it commanded a consistent price on the world market, a factor which contributed to the financial stability of the area. The increased income from wool provided scope for unprecedented commercial activity. The new found wealth which was diffused among the white farmers raised their standard of living. Predial labour did not, however, experience commensurate material gains. The social and cultural milieu was not profoundly affected but material prosperity fostered greater political awareness among wool farmers, a factor which was to bolster Afrikaner national movements after 1870. / History / D. Litt. et Phil. (History)

The research was conducted in the Hewu area situated between Queenstown (20 km) and Whittlesea (15km) in the Eastern Cape Province of South Africa. In this area communal farming is practiced. Livestock and livestock products (wool) are the main sources of income. The farmers are mainly farming with Merino and Döhne Merino sheep. The lack of management systems (production, reproduction and management) for communal farmers resulted into ineffective communal farming defining the research problem. The research objectives set were: • To establish production norms for wool sheep. • To establish reproduction norms for wool sheep. • To establish effective management practices for wool sheep farmers. • To examine key constraints of wool sheep farmers. The farmers shear their sheep every 12 months usually in October of every year. The average wool production per sheep is 2.17kg. The clip averages a fineness of 19.1-20 micron. That is far below the wool production of the commercial farmers of the Eastern Cape who are producing between 4kg to 5kg per sheep at an average growing period of 12 months. The lack of proper fencing and camps causes major reproduction problems. The lambing percentage of the ewes is 94.85 percent. The weaning percentage referring to the reproductive efficiency of the mated ewes is only 17.24 percent. The survival rate of the lambs born alive is only 18.18 percent. Reproduction is the biggest problem of communal farms. Effective livestock- and grazing management systems for communal areas are essential for the successful development of farmers on communal grazing areas. Unfortunately the Hewu farmers still have many problems effecting their wool production and the production of lambs.

The objective of the study was to determine sheep growth performance, fleece weights and wool quality characteristics in the sweet and sourveld communal rangelands of the Eastern Cape Province of South Africa. Data were obtained in 80 ewes aged two to three years, selected in four ecologically different communities. Two communities (Roxeni and Tyabane) were in a sweetveld area and the other two communities (Luzi I and Luzi II) were in a sourveld area. The ewes from Tyabane were nondescript, whereas ewes from Roxeni, Luzi I and Luzi II were crossbred between Merinos and non-descript sheep. Selected ewes were monitored for live weight, body condition scoring and fleece weight during shearing. Wool samples were collected from each ewe and were analysed for fibre diameter, comfort factor, clean yield, wool crimps, staple length, staple strength and the Position of break. Sheep from Roxeni were heavier (P <0.05) (39.9 ± 1.1kg) than sheep from Tyabane (29.8 ± 1.1kg). Sheep from Tyabane had the lightest (P <0.05) fleece weight (1.0 ± 1.1kg) and sheep from Roxeni had the heaviest (3.1 ± 1.1kg). There were no significant differences (P ≥0.05) between body condition scores of sheep in Roxeni and the Luzi communities. The live weights of the two-year old ewes were similar (P ≥0.05) to the three-year old ewes’ live weight. However, the three year old ewes had higher (P <0.05) body condition scores than the two year old ewes. Two year old ewes also had lower (P <0.05) fleece weight than the three years old ewes. Wool from Roxeni, Luzi I and Luzi II had lower fibre diameter (P <0.05) than wool from Tyabane. Roxeni sheep had the highest clean yield (P <0.05) of wool, followed by Luzi I and Luzi II; Tyabane had lowest clean yield percentage of wool. Wool from sheep grazing on sweetveld had a higher (P <0.05) clean yield percentage (74.3 ± 0.7%) than those grazing on sourveld (71.7 ± 0.7%). There were higher staple mid-breaks (69.5 ± 5.2) and lower base-breaks (30.5 ± 5.2) in sweetveld (P <0.05) than in sourveld, 7.5 ± 5.2 and 92.5 ± 5.2 for mid-breaks and lower base-breaks, respectively. It was concluded that sheep raised in the sweetveld and bred with purebred Merino rams had higher performance than the ones reared in the sourveld. The young upgraded ewes had a higher wool quality than the older ewes raised on communal rangelands.