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dc.contributor.advisorVan der Merwe, H. J.
dc.contributor.advisorCilliers, J. W.
dc.contributor.authorVan Vuuren, Barend Gerhardus Jansen
dc.date.accessioned2017-04-24T09:54:02Z
dc.date.available2017-04-24T09:54:02Z
dc.date.issued2000-05
dc.identifier.urihttp://hdl.handle.net/11660/6138
dc.description.abstractEnglish: The aim of this study was to evaluate the biological and economical feasibility of wool sheep farming in the Western Highveld of South Africa. The performance of young sheep utilizing Digitaria eriantha Steud. (Smuts finger grass) both during the winter and summer periods, fertilised at rates of 60 kg N + 10 kg P/ha vs. 120 kg N + 20 kg P/ha, was investigated. Rainfall, both in terms of quantity and distribution, was the most critical factor during both the summer and winter seasons. During the winter period, the quantity rather than the quality, of the foggage was the limiting factor. The results of this study, with the below normal rainfall recorded, showed that stocking rates of two, four and six sheep/ha for a six month period are sufficient for the maintenance requirements of wooled sheep. During these dry seasons a fertilization rate higher than 60 kg N + 10 kg P/ha had no beneficial effect as far as mass gain/ha is concerned. The results obtained during the summer period were also very disappointing, mainly due to a lack of available pasture. Rotational grazing, instead of continuous grazing, should probably rather be applied during the summer period. The biological and economical feasibility of three various wintering strategies (silage, foggage/crop residues and veld) of Merino ewes and their progeny, for both an autumn and a spring lambing season, were also evaluated. This study indicated that the utilisation of Smuts finger grass foggage and crop residues during winter, realised the best results for animals of both lambing seasons. However, the biological and economical availability of the various feed sources would ultimately be the deciding factor on the most appropriate system. Although the animals of the intensive treatment (silage) had the best performance (mainly in terms of body mass and mass gain), the animals of the foggage/ crop residue treatment showed compensatory growth during the summer period. This resulted in little or no differences in the body mass of these two treatments at the end of the summer period. In the case of ewes utilising winter veld, their compensatory growth was insufficient for a total recovery in body mass. Ewes wintered on maize silage as the sole roughage source returned the highest body masses and body mass gains. However, this advantage was not transferred to the performance of their progeny and the quality and quantity of the wool produced. The conclusion was made that natural protein supplementation should be provided additional to the silage, especially for woolled sheep. Cost of the silage will also exert a great influence on the financial viability of this enterprise, as this proved to be the highest feed cost. Maize crop residues proved to be an invaluable, high energy feed source that becomes available at a crucial time in the fodder flow for woolled sheep. This product also has little or no other commercial value. Despite the lower clean wool percentage, animals of this treatment still realised the highest clean wool mass (kg). The greater fiber diameter was also not so severe as to cause a reduction in price. The poor performance of the ewes on winter veld was disappointing. In the long term, this does not appear to be a viable option. Where available, an alternative nutritional strategy should be applied. This extensive treatment can also be seen as a 'Iow cost approach' with reduced inputs and, consequently, a reduced income. Ewes lambing during spring required less supplementation. This was mainly due to the fact that they utilised crop residues during late pregnancy and they raised their lambs during spring. For both the lambing seasons the utilisation of foggage/crop residue realised the highest and the animals of the silage treatment the lowest gross margin for all the parameters tested (gross margin per small stock unit and per ewe), the only exception being the gross margin/ha, which was higher for the intensive treatment than that of the extensive treatment during the spring lambing season. The cost of intensification should, however, be kept in mind. The results of this investigation clearly indicated the biological and economical advantages of utilising foggage/maize crop residues during the winter months.en_ZA
dc.description.abstractAfrikaans: Die doel van die studie was om die biologiese en ekonomiese doeltreffendheid van wolskaapboerdery in die Westelike Hoëveld van Suid Afrika te bepaal. Met die benutting van Oigitaria eriantha Steud. (Smutsvingergras), beide gedurende die somer- en winterperiodes, bemes teen peile van 60 kg N + 10 kg P/ha vs. 120 kg N + 20 kg P/ha, blyk reënval ten opsigte van hoeveelheid, sowel as die verspreiding, die mees kritiese faktor te wees. Gedurende die winter was die hoeveelheid, eerder as die kwaliteit, van die staande hooi die beperkende faktor. Gesien in die lig van die lae reënval wat gedurende hierdie ondersoek aangeteken is, was veeladings van twee, vier en ses skape/ha slegs voldoende vir die massa-onderhoud van wolskape. Die resultate wat gedurende die somerperiode behaal is, was ook baie teleurstellend. Gedurende hierdie droë seisoene wil dit voorkom asof bemestingspeilie bo 60 kg N + 10 kg P/ha geen voordeel, ten opsigte van massatoename/ha, inhou nie. Dit was hoofsaaklik as gevolg van 'n gebrek aan beskikbare weiding. Wisselweiding, in plaas van aanhoudende beweiding, gedurende die somer sou waarskynlik beter resultate tot gevolg gehad het. Die biologiese en ekonomiese lewensvatbaarheid van drie oorwinteringstrategieë (kuilvoer, staande hooi/oesreste en veld) van Merino-ooie en hul nageslag is, ten opsigte van beide 'n herfs- en lentelamseisoen, ondersoek. Die resultate van hierdie ondersoek het getoon dat die benutting van Smutvingergras- staande hooi, tesame met oesreste gedurende die winter, die beste ekonomiese resultate gelewer het, ten opsigte van beide lamseisoene. Die mees geskikte sisteem sal uiteindelik egter grootliks deur die biologiese en ekonomiese beskikbaarheid van voerbronne bepaal word. Alhoewel die diere van die intensiewe behandelings gedurende die winter (hoofsaaklik ten opsigte van liggaamsmassa en massatoename), beter presteer het, het die diere van die staande hooi/oesreste-behandeling kompenserende groei gedurende die somer getoon. Dit het tot gevolg gehad dat die diere van dié twee behandelings (in terme van liggaamsmassa) min of geen verskil aan die einde van die somer getoon het nie. Die ooie wat winterveld benut het, het egter nie voldoende kompenserende groei getoon om 'n totale herstel in liggaamsmassa te bewerkstellig nie. Ten spyte van die feit dat ooie wat op mieliekuilvoer as enigste ruvoerbron oorwinter het die hoogste liggaamsmassa en massatoename gedurende die winterperiode getoon het, was hierdie voordeel nie waarneembaar in die prestasie van hul lammers en hul wolproduksie nie. Die gevolgtrekking is gemaak dat In natuurlike proteïenbron as aanvulling tot mieliekuilvoer noodsaaklik is vir wolskape. Aangesien kuilvoer die hoogste voerkoste by hierdie behandeling verteenwoordig het, sal die prys van die kuilvoer die bepalende faktor in die winsgewendheid van hierdie onderneming wees. Mielieoesreste bly steeds 'n waardevolle hoë-energie voedingsbron, met min of geen ander kommersiële waarde. Hierdie voerbron is op 'n kritieke tydstip in die voervloeiprogram vir skape gereed vir benutting. Ten spyte van die laer skoonopbrengs van hul wol, het die ooie van hierdie behandeling nog steeds die hoogste skoonwolmassa gelewer. Die veseldikte was ook nie soveel hoër dat dit 'n laer prys gerealiseer het nie. Die teleurstellende prestasie van die ooie wat op winterveld gewei het, toon aan dat, waar beskikbaar, 'n alternatiewe voerbron gedurende die winter benut moet word. Hierdie ekstensiewe benadering kan egter ook beskou word as 'n lae-koste benadering met laer insette en gevolglike laer diereprestasie en, gevolglik ook, laer inkomste. Die feit dat die ooie van die lentelamseisoen gedurende laat dragtigheid op oesreste wei en hul lammers gedurende die lente soog, het tot gevolg gehad dat hul minder aanvulling benodig. By beide lamseisoene het die ooie wat staande hooi/oesreste gedurende die winter benut het die hoogste, en dié wat kuilvoer benut het die laagste, bruto marge (per kleinvee-eenheid en per ooi) gerealiseer. AI uitsondering hier is die bruto marge/ha. Die bruto marge/ha van die intensiewe behandeling se ooie was hoër as dié van die ekstensiewe behandeling. Die koste verbonde aan intensifikasie moet egter hier in gedagte gehou word. Die resultate van hierdie ondersoek het die biologiese en ekonomiese voordele verbonde aan die benutting van oesreste/staande hooi gedurende die winter duidelik beklemtoon.af
dc.description.sponsorshipUniversity of the Free State, Department of Agricultureen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectSheep -- South Africa -- Highveld -- Feeding and feedsen_ZA
dc.subjectThesis (Ph.D. (Animal Science))--University of the Free State, 2000en_ZA
dc.titleWool sheep production systems for the Western Highveld of South Africaen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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