Spelling suggestions: "subject:"dissertations -- agriculture"" "subject:"dissertations -- griculture""
71 |
Huil by die wynstokVan Reenen, Christiaan Frederik January 1946 (has links)
Thesis (MScAgric)--Stellenbosch University, 1946. / No Abstract Available
|
72 |
n Fisiologiese studie van vier Suid-Afrikaanse gisrasse met betrekking tot vlugtige suur- en alkoholvormingVan Zyl, J. A. January 1954 (has links)
Thesis (MScAgric)--Stellenbosch University, 1954. / No Abstract Available
|
73 |
Die ontstaan en voorkoms van gliserien by die gisting van druiwemosVenter, P. J. January 1955 (has links)
Thesis (MScAgric)--Stellenbosch University, 1955. / No Abstract Available
|
74 |
Die funksie van mangaan in Suid-Afrikaanse wyneGous, S. J. (Sarel Jacobus) January 1934 (has links)
Thesis (MSc)--Stellenbosch University, 1934. / No Abstract Available
|
75 |
Die invloed van bemesting op die opneembare stikstof in twee grondtipes onder wingerdBurger, Roelof du T. (Roelof du Toit) January 1951 (has links)
Thesis (MScAgric)--Stellenbosch University, 1951. / No Abstract Available
|
76 |
Invloed van doppenetrasieweerstand op die oesstadium van druiweVan Dyk, B. W. (Burger Wynand) January 1992 (has links)
Thesis (MScAgric)--Stellenbosch University, 1992. / One microfiche copy / ENGLISH ABSTRACT: The possibility of harvesting grapes at an earlier stage of maturity, based on
differences in glucose and fructose concentration which influence the sweetness of
grapes, was investigated. Although differences between cultivars were found the
extent was not such that a specific cultivar could be selected in order to harvest at a
lower sugar concentration, but with the same sweetness. Certain characteristics of
table and wine grape cultivars with respect to anatomical composition and skin
penetration resistance (SPR) were also investigated in order to ascertain the extent
to which grapes would resist external damage, and to what extent turgor and skin
thickness contributed to SPR. Daily variances in SPR confirm that not only skin
strength, but also the turgor of the grape berry contributed to SPR. Skin
penetration resistance seems to be a good criterion of the extent to which cultivars
would resist external damage, because it is based on the toughness of the skin and
the turgor of the berry. / AFRIKAANSE OPSOMMING: Die moontlikheid van vroeer oes op grond van verskille in die glukose- en fruktosekonsentrasie
wat 'n invloed op die soetheid van druiwe mag he, is ondersoek. Daar
is gevind dat die verskille wat tussen cultivars voorkom nie van so 'n grootte-orde is
dat 'n spesifieke cultivar geselekteer kan word ten einde by 'n laer totale suiker,
maar by dieselfde soetheidsgraad, te kan oes nie. Verder is sekere eienskappe van
tafel- en wyndruifcultivars t.o.v. anatomiese samestelling en doppenetrasieweerstand
(DP\V) ondersoek om die moontlike weerstand teen eksterne
beserings en die mate waartoe turgor en dopdikte 'n invloed daarop mag uitoefen,
_vas te stel. Daaglikse variasie in DPW het bevestig dat die DPW nie alleen
afhanklik is van dopsterkte nie, maar ook van die turgor van die korrel.
Doppenetrasieweerstand blyk 'n goeie maatstaf te wees vir die mate waartoe
cultivars weerstand hied teen sekere eksterne beserings omdat dit gebaseer is op
dopsterkte en turgor van die korrel.
|
77 |
Grape and wine quality of V. vinifera L. cv. Cabernet Sauvignon/99R in response to irrigation using winery wastewaterSchoeman, Charl 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Grapevine performance and wine quality are influenced by various factors, two of the most important being the availability and quality of irrigation water. In relatively dry countries such as South Africa the conservation and effective use of water is of utmost importance. Expected increases in temperature and decreases in rainfall in the future due to climate change impacts highlights the importance of water conservation. This inspired investigations into possible alternative irrigation water sources and therefore the possibility of vineyard irrigation using winery wastewater is of utmost importance for the sustainability of the wine industry.
Winery wastewater contains higher concentrations of certain elements other than water generally used for vineyard irrigation, the most important differences being Na and K levels. Furthermore, winery wastewater contains larger populations of microorganisms such as yeasts, lactic acid bacteria and acetic acid bacteria, typical associated with wine production. If irrigation using winery wastewater affects the uptake of certain elements or alters grapevine water status, it may affect grapevine growth, juice and wine composition. Furthermore, if juice and wine composition is affected wine composition and sensorial quality may be affected.
Cabernet Sauvignon/99R grapevines, growing in a sandy soil in the Breede River Valley, were subjected to eight irrigation treatments using augmented winery wastewater in addition to irrigation using raw river water as control. The study was carried out during the 2010/11 and 2011/12 seasons. The various wastewater irrigation treatments were made up by augmenting winery wastewater with raw river water to obtain a target chemical oxygen demand (COD) concentration. In this study, the level of COD in the irrigation water is a direct indication of water quality, the two being indirectly proportional. The eight wastewater irrigation treatments ranged from 100 mg/L COD up to 3000 mg/L COD.
The first objective of the study was to determine the effect of irrigation using augmented winery wastewater on grapevine response, with regards to vegetative growth, berry development and berry composition. The various wastewater irrigation treatments did not affect grapevine vegetative growth or reproductive growth, including yield, throughout berry development up to harvest. Berry sugar accumulation and evolution in acid concentrations were also not affected. An increase in berry juice pH was observed with an increase in the level of COD in the augmented winery wastewater only in the second season. The amount of elements, ions and heavy metals in juice was not affected by wastewater irrigation, indicating that there was no absorption by the grapevines. Berry skin thickness, colour and phenolic content as well as yield and its associated components were not affected by irrigation using augmented winery wastewater.
The second objective of the study was to determine the effect of irrigation using augmented winery wastewater on wine microbial and chemical composition, fermentation performance and wine sensorial characteristics. The natural yeast and bacteria flora of juice was not affected by the various wastewater irrigation treatments. In addition, the ability of the inoculated yeast and lactic acid bacteria strains to conduct their respective fermentation processes were not affected. With the exception of total titratable acidity (TTA) and pH, irrigation using augmented winery wastewater did not affect wine chemical composition with regards to basic wine parameters as well as colour, phenolic and tannin composition. Similar to juice, phosphorus and selected ions were not affected. None of the measured wine sensorial characteristics were affected by irrigation using augmented winery wastewater.
The third objective of the study was to investigate the effect of direct contact between berries and winery wastewater on wine sensorial characteristics. The study focussed on the transference of off-flavours from the wastewater into the wine and the occurrence of off-flavours as a response to contact with winery wastewater. Wine colour and general sensory wine descriptives were not affected by direct contact with winery wastewater. The presence of a winery wastewater-like off-odour and volatile acidity was, however, more detectable in wines made from berries that were in contact with the most concentrated wastewater. Therefore, it may be possible for off-odours to be transferred from the winery wastewater into the wines, or that off-odours are formed as a direct or indirect result of contact with winery wastewater.
Under the given conditions, results obtained in this two seasons of the study suggest that irrigation using augmented winery wastewater does not affect grapevine performance or wine quality substantially. The major impact that was observed was an increase in wine pH and a decreasing trend in TTA. Both these parameters could be rectified by simply adding acid to the wines. Therefore, irrigation using augmented winery wastewater may be considered as a possible future alternative source for vineyard irrigation. It is, however, important to remember that some of the effects of wastewater irrigation may be cumulative and could possibly arise only after several years. Furthermore, different field conditions and cultivars may respond differently. / AFRIKAANSE OPSOMMING: Wingerd prestasie en wyngehalte word deur verskeie faktore beïnvloed waarvan twee van die belangrikste die beskikbaarheid en gehalte van besproeiingswater is. In relatiewe droë lande soos Suid Afrika is waterbesparing en die effektiewe benutting van water hulpbronne van uiterste belang. Die verwagte toename in temperatuur en afname in reënval in die toekoms as gevolg van klimaatsveranderinge plaasdieklem op op die belangrikheid van waterbesparing. Dit het navorsing om moontlike alternatiewe vorme van besproeiingswater te ontdek geïnspireer. Na aanleiding van hierdie faktore word daar toenemend gefokus op navorsing oor die moontlikheid om kelder afvalwater as alternatiewe bron van besproeiings water vir wingerde te benut.
Kelder afvalwater bevat hoër konsentrasie van sekere elemente as water wat onder normale omstandighede gebruik word vir die besproeiing van wingerde, die belangrikste verskille was die vlakke van Na en K. Benewens die hoër konsentrasie van sekere elemente bevat kelder afvalwater ook groot populasies van mikroörganismes soos giste, melksuurbakterieë en asynsuurbakterieë, tipies geassosieerd met wynbereiding. Indien besproeiing met kelder afvalwater die opname van sekere elemente of die plant water status beϊnvloed, mag wingerd groei, sap en wyn samestelling beϊnvloed word. Daar benewens, indien die mikrobiese samestelling van die sap en wyn beϊnvloed word sal die samestelling en sensoriese gehalte van die wyn moontlik beϊnvloed word.
Cabernet Sauvignon/99R wingerde, geleë in sanderige grond in die Breede Rivier Vallei, is onderwerp aan besproeiing met agt verskillende konsentrasies van verdunde kelder afvalwater, bykomend tot besproeiing met onbehandelde rivier water wat as kontrole gedien het. Hierdie studie is uitgevoer gedurende die 2010/11 en 2011/12 seisoene. Die teiken besproeiings konsentrasies is verkry deur kelder afvalwater met onbehandelde rivier water te verdun tot ‘n sekere chemiese suurstofbehoefte (CSB) konsentrasie bereik is. Die CSB is in hierdie studie ‘n direkte aanduiding van watergehalte, die twee was indirek eweredig tot mekaar. Die agt CSB konsentrasies waarteen die afvalwater besproei is wissel tussen 100 mg/L CSB en 3000 mg/L CSB.
Die eerste doelwit van die studie was om te bepaal wat die effek van besproeiing met verdunde kelder afvalwater op wingerdprestasie, met spesifieke verwysing na vegetatiewe groei, korrelontwikkeling en korrelsamestelling is. Wingerd vegetatiewe en reproduktiewe groei, insluitende opbrengs, is op geen stadium tydens korrelontwikkeling tot en met oes beïnvloed nie. Die laai van suikers gedurende rypwording, sowel as verskuiwings in suurkonsentrasie, is nie deur besproeiing met kelder afvalwater beïnvloed nie. In die tweede seisoen is ‘n toename in sap pH waargeneem soos die CSB konsentrasie van die besproeiings water toegeneem het. Die element, ioon en swaar metaal samestelling van sap was nie beïnvloed deur besproeiing met afvalwater nie wat aandui dat daar geen opname was deur die wingerd nie. Die dikte, kleur en fenoliese samestelling van druifdoppe is ook nie beïnvloed nie.
Die tweede doelwit van die studie was om te bepaal wat die effek van besproeiing met verdunde kelder afvalwater op wyn mikrobiese en chemiese samestelling, fermentasie effektiwiteit en wyn sensoriese eienskappe is. Die verskeie afvalwater besproeiings behandelings het geen effek op die natuurlike gis of bakterieë flora van die sap gehad nie. Die vermoë van die geïnokuleerde gis en melksuurbakterieë om hul afsonderlike fermentasie prosesse te voltooi is ook nie beïnvloed nie. Met die uitsondering van totale titreerbare suur (TTS) en pH, is die chemiese samestelling van wyne met betrekking tot basiese wyn parameters, kleur, fenole en tanniene nie beïnvloed nie. Soortgelyk aan sap is wyn fosfor en geselekteerde ioon samestelling nie geaffekteer nie. Die sensoriese karakteristieke was eenders vir wyne van alle behandelings.
Die derde doelwit van die studie was om te bepaal wat die effek wat direkte kontak van kelder afvalwater met druiwekorrels op wyn sensoriese eienskappe het. Hierdie studie het gefokus op die oordrag van afgeure vanaf kelder afvalwater na die wyne sowel as die voorkoms van afgeure as ‘n reaksie op kontak met kelder afvalwater. Wyn kleur en algemene sensoriese eienskappe is nie geaffekteer deur kontak tussen druiwe en kelder afvalwater nie. Kelder afvalwater-geassosieerde afgeure en vlugtige suur was meer duidelik waarneembaar in wyne wat gemaak is van druiwe wat in kontak was met die meer gekonsentreerde afvalwater. Dit mag dus moontlik wees dat afgeure vanaf kelder afvalwater oorgedra word na wyne, of dat sekere afgeure gevorm word as ‘n direkte of indirekte reaksie op kontak met kelder afvalwater.
Onder die gegewe toestande oor die twee jaar studie periode het resultate getoon dat besproeiing met verdunde kelder afvalwater nie wingerdprestasie en wyn gehalte aansienlik beïnvloed nie. Die grootste impak wat afvalwater besproeiing gehad het, was om ‘n toename in wyn pH en ‘n tendens tot afname in TTS te veroorsaak. Deur eenvoudig suur by die wyn te voeg kan albei hierdie probleme reg gestel word. Op grond van hierdie bevindings kan besproeiing met verdunde kelder afvalwater moontlik as toekomstige bron vir addisionele wingerdbesproeiing dien. Dit is egter belangrik om te onthou dat die effekte van besproeiing met kelder afvalwater mootlik kumulatief kan wees en dat probleme moontlik eers na etlike jare na vore kan kom. Ander kultivars en veldkondisies mag ook lei tot ander resultate.
|
78 |
Die kallusvormingsvermoe van verskillende wingerdonderstokcultivars (vitis) en die invloed van kallusstimulanteGoussard, P. G. (Pieter Gabriel) 03 1900 (has links)
Thesis (MSc) -- Stellenbosch University, 1975. / No abstract available
|
79 |
The effect of maturity and crop load on the browning and concentration of phenolic compounds of Thompson Seedless and Regal SeedlessKamfer, De Witt 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Thompson Seedless and Regal Seedless are two white seedless table grape
cultivars widely produced in South Africa. Both cultivars are susceptible to berry
browning, especially Regal Seedless. Browning leads to annual financial losses for
table grape growers. Although a correlation between harvest maturity and the
occurrence of browning seems to exist, it is still unclear whether maturity levels are
the actual contributing factor. The aim of the study was to establish if harvest
maturity and crop load could influence the occurrence of browning of both cultivars.
The impact of harvest maturity and crop load on phenolic compound concentration in
the berry skin of both cultivars was also investigated. Total external browning of
Regal Seedless and Thompson Seedless occurred in much higher percentages than
internal browning. Regal Seedless showed a tendency to decreased total external
browning with harvest maturity. The main reason for this is that net-like browning,
which is the greatest contributor to total external browning, decreased with harvest
maturity, in all three seasons. External browning of Thompson Seedless increased
with harvest maturity in both seasons. Contact browning was the greatest contributor
to total external browning of Thompson Seedless. Crop load did not significantly
influence berry browning of Regal Seedless or Thompson Seedless grapes. The
flavan-3-ol concentration (catechin, epicatechin, procyanidin B1 and procyanidin B2)
in Regal Seedless generally increased with harvest maturity, whereas in Thompson
Seedless the general tendency was a decrease in the flavan-3-ol concentration with
harvest maturity. The development of phenolic compound concentration with
maturity could not be correlated with the occurrence of berry browning. Crop load did
not affect flavan-3-ol concentration. When the flavan-3-ol concentration of Regal
Seedless and Thompson Seedless were compared at different harvest maturities the
concentrations of flavan-3-ols were clearly much higher in the skin of Regal Seedless than in the skin of Thompson Seedless (for both the 2008 & 2009
seasons). Comparison of the browning incidence with harvest maturity for these two
cultivars (see above) clearly reveals that external browning of Regal Seedless
occurred in much higher percentages than on Thompson Seedless. Regal Seedless
had much higher levels of external browning than Thompson Seedless. The
concentration of flavan-3-ols in the skin of white seedless cultivars may be an
indication of the cultivar’s susceptibility to external browning. / AFRIKAANSE OPSOMMING: Thompson Seedless en Regal Seedless is twee wit pitlose tafeldruif kultivars wat
ekstensief in Suid-Afrika verbou word. Verbruining kan ‘n probleem wees by beide
kultivars, spesifiek Regal Seedless. Die faktore wat aanleiding gee tot verbruining is
nog nie duidelik bepaal nie. Alhoewel dit lyk of daar ‘n korrelasie tussen
rypheidsgraad van die oes en verbruining kan wees is dit steeds onduidelik of
oesrypheidsvlakke die werklike oorsaak van verbruining is. Die doel van die studie
was om vas te stel of die rypheidsgraad van die oes en oeslading verbruining van
beide kultivars kan beïnvloed. Die effek van oes rypheidsgraad en oeslading op
konsentrasie van fenoliese verbindings in die korrelskil van beide kultivars is ook
ondersoek. Totale eksterne verbruining van Regal Seedless en Thompson Seedless
het in baie hoër persentasies voorgekom as interne verbruining. Daar was ‘n
tendens by Regal Seedless dat totale eksterne verbruining verminder het soos die
oes ryper geraak het as gevolg van netagtige verbruining, wat die grootste bydrae tot
totale eksterne verbruining veroorsaak het. Netagtige verbruining se voorkoms het
verminder oor al drie seisoene. Eksterne verbruining van Thompson Seedless het
toegeneem met oes rypheid in beide seisoene. Kontak verbruining het grootste
byrdae gelewer tot totale eksterne verbruining van Thompson Seedless. Oeslading
het nie ‘n betekenisvolle invloed op verbruining van Regal Seedless en Thompson
Seedless gehad nie. Die flavan-3-ol (katesjien, epikatesjien, prosianidien B1 en
prosianidien B2) konsentrasie van Regal Seedless het met oes rypheid toegeneem.
By Thompson Seedless was daar ‘n afname in die flavan-3-ol konsentrasie met oes
rypheid. Daar was geen korrrelasie tussen die konsentrasie van fenoliese verbinding
en die voorkoms van verbruining vir beide kultivars. Oeslading het nie ‘n
betekenisvolle effek op die konsentrasie van fenoliese verbindings gehad nie.
Vergelyking van die flavan-3-ol konsentrasie van Regal Seedless en Thompson
Seedless by verskillende rypheidsgrade wys dat die konsentrasie baie hoër in die korrel skil van Regal Seedless as in die van Thompson Seedless (vir beide 2008 &
2009 seisoene). Die vergelyking van die voorkoms van verbruining met oesrypheid
van beide kultivars wys duidelik dat eksterne verbruining van Regal Seedless in baie
hoër persentasies voorkom as in Thompson Seedless. Flavan-3-ol konsentrasie in
die skil van wit pitlose kultivars kan ‘n aanduiding wees van die kultivar se moontlike
risiko vir die voorkoms van eksterne verbruining.
|
80 |
Veterinary public health aspects related with food-producing wildlife species in the domestic animal, human and environment interfaceMagwedere, Kudakwashe 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The wildlife industry in Namibia continues to grow as the production and consumption of game meat increases. However, the health risks posed by the trade in wildlife and related by-products to livestock and humans have not been fully assessed. The main objective of this study was to investigate the potential health risks related to the increased consumption of game meat and relevant by-products by assessing the quality of game meat, as well as determine the role of game meat species in the transmission of zoonoses.
The microbiological quality and safety of export game meat was assessed. No differences in the aerobic plate count (APC) were observed between the years (2009 and 2010), but the mean Enterobacteriaceae count was 1.33±0.69log10 cfu/cm2 compared to 2.93±1.50log10 cfu/cm2 between the years. Insignificant heterotrophic plate count (HPC) levels were detected in 9/23 field water samples, while faecal bacteria (coliforms, Clostridium perfringens and enterococci) were not isolated in all samples. Seven serogroups, with the exception of O26, were detected in exotic species. A white tailed deer sample had a serotype belonging to O45 which confirmed positive for stx1 gene. In springbok, 5/15 pools of faecal samples tested positive for the intimin gene. No Salmonella spp were isolated, and all E. coli isolates from the meat samples were negative for STEC virulence genes (i.e. stx1, stx2, eae and hlyA).
A linear regression analysis was conducted on selected variables to identify the main predictors and their interactions affecting pH of meat 4 hours post-slaughter. In an increasing order of magnitude during winter time, the pH reached at 16-36hr post slaughter in springbok heart, liver, spleen, kidney and lungs was significantly higher than pH 6.0, while no significant differences were observed from the regulatory reference (pH 6.0) in the heart. There was a positive association between the pH of game meat 4hr post-slaughter, and liver congestion. The pH of game meat 4hr post slaughter, increased by 0.11 units per mL increase in liver congestion, and decreased by 0.04 units per minute increase in the shooting to bleeding interval, irrespective of the species.
Worm eggs of strongylids, Strongyloides papillosus, Toxocara spp, Trichuris spp and coccidia were found in variable numbers in both springbok and gemsbok faeces, indicating a potential risk of transmission to other species in the ecosystem. On examination of carcasses, a novel parasite, Skjabinodera kuelzii, was identified and noted to be associated with inguinal fascia and renal fat, but the public health significance remains unclear. Nevertheless, S. kuelzii should be considered as of potential significance during routine game meat inspection.
A total of 12 310 springbok were harvested from 26 commercial farms over a period of two years. Tissue samples (i.e. 60 livers, 41 kidneys and 52 hindquarter muscles) were collected from randomly selected healthy animals. The mean values (i.e. above the detection limit) of cadmium (Cd) and lead (Pb) were 0.10±0.05mg/kg and 1.04±0.21mg/kg in the liver, respectively; and 0.33±0.22mg/kg and 0.905±0.51mg/kg in the kidney of springbok, respectively. The levels of cadmium and lead in the hindquarter muscles were below the detection limit.
Serum samples (n=1692) collected from sheep, goats and cattle from four presumably at-risk farms, and 900 springbok (Antidorcas marsupialis) serum samples collected from 29 mixed farming units, were screened for Brucella antibodies by using the Rose-Bengal test (RBT). Positive cases were confirmed by complement fixation test (CFT). To assess the prevalence of human brucellosis, 137 abattoir employees were tested for Brucella antibodies using the standard tube agglutination test (STAT), and the enzyme linked immunosorbent assay (ELISA). Cattle and sheep from all four farms were negative by RBT and CFT, but two of the four farms carried 26/42 and 12/285 seropositive goats, respectively. Post mortem examination of seropositive goats revealed no gross pathological lesions. Culture for brucellae from organs of seropositive animals was negative. None of the wildlife sera tested positive by either RBT or CFT. Occurrence of confirmed brucellosis in humans was linked to the consumption of unpasteurized goat milk, home-made goat cheese and coffee with raw milk and prior contact with goats. All abattoir employees (n=137) tested negative by STAT, but 3 were positive by ELISA. The three abattoir workers were clinically normal, and lacked historical connections with clinical cases.
This study illustrates the importance of microbiological, parasitic and residue monitoring as critical components of a hazard analysis and critical control point based system for game meat. The study also provides the basis for increased integrated health research, surveillance and meat safety risk analysis. / AFRIKAANSE OPSOMMING: Die Namibiese wildbedryf raak toenemend groter soos die produksie en verbruik van wildsvleis toeneem. Die verwante gesondheidsrisiko’s wat die gebruik van wildsvleis en verwante produkte vir mens en dier inhou, is nog nie volledig geassesseer nie. Die doelwit van die studie was om ondersoek in te stel na die potensiële gesondheidsrisiko's wat wildsvleis en verwante neweprodukte vir mens en dier inhou deur middel van die assessering van vleisgehalte en die bepaling van die rol van die wildsvleis spesies in die oordrag van soönoses.
Die mikrobiologiese gehalte en veiligheid van uitvoer wildsvleis was geassesseer. Geen verskille in die aerobiese plaat telling (APC) vir monsters versamel tydens 2009 en 2010 is aangeteken nie. Die gemiddelde Enterobacteriaceae telling was 1.33± 0.69log10 cfu/cm2 in vergelyking met 2.93±1.50log10 cfu/cm2 tussen die jare. Onbeduidende heterotrofe plaattelling (HPC) vlakke is waargeneem in 9/23 water monsters, terwyl fekale bakterieë (d.i. kolivorme, Clostridium perfringens en enterokokke) nie in enige van die monsters geïsoleerd is nie. Sewe serogroepe, met die uitsondering van O26, is aangeteken vir die eksotiese spesies. Monsters verky van ʼn white tailed deer is as positief vir 'n serotipe van O45 getoets, en die teenwoordigheid van die stx1 geen is bevestig. In springbok het 5/15 poele van fekale monsters positief getoets vir die intimien geen. Geen Salmonella spp is geïsoleer nie en alle E. coli geïsoleer in die vleismonsters was negatief vir die Stec virulensie geen (d.i. stx1, stx2, EAE en hlyA).
ʼn Liniêre regressie-analise is op geselekteerde veranderlikes wat as die belangrikste indikators kan dien, en enige moontlike interaksie wat die pH van wildsvleis 4 uur na-slag kan beïnvloed, uitgevoer. In 'n toenemende orde van grootte gedurende die winter tyd, die pH teen 16-36hr na slagting in springbok hart, lewer, milt, niere en longe was aansienlik hoër as die pH 6.0, terwyl geen beduidende verskille waargeneem is wanneer dit met die regulasie verwysingswaarde van die hart (pH 6.0) vergelyk is nie. Daar was 'n positiewe assosiasie tussen die pH van wildsvleis 4 uur na-slag en mate van aansameling in die lewer. Die pH van wildsvleis 4 uur na-slag, het toegeneem met 0.11 eenhede per mL toename in lewer aansameling en afgeneem met 0.04 eenhede per minuut toename in die skiet tot uitbloei interval, ongeag die spesie.
Wurmeiers van rondewurms, Strongyloides papillosus, Toxocara spp, Trichuris spp en koksidia het in verskillende ladings in die mis van beide springbok en gemsbok ontlasting, voorgekom. Dit dui op 'n potensiële risiko van oordrag na ander spesies in die ekosisteem. Die voorkoms van ʼn nuwe parasiet, Skjabinodera kuelzii, in wildskarkasse is aangeteken en was geassosieer met inguinale fascia en renale vet, maar die openbare gesondheidsrisiko bly onduidelik. Daar word aanbeveel dat dié parasiet as ʼn potensiële risiko faktor tydens roetine vleisinspeksies beskou moet word.
ʼn Totaal van 12 310 springbokke is oor 'n tydperk van twee jaar van 26 kommersiële plase geoes. Weefselmonsters (d.i. 60 lewers, 41 niere en 52 agterkwart spiere) is ewekansig versamel van gesonde diere. Die gemiddelde waardes (d.i. hoër as die opsporingslimiet) van kadmium (Cd) en lood (Pb) was 0.10 ± 0.05mg/kg en 1.04 ± 0.21mg/kg in die lewer onderskeidelik en 0.33 ± 0.22mg/kg en 0.905 ± 0.51mg/kg in die niere van springbok, onderskeidelik. Die vlakke van kadmium en lood in die agterkwart spiere was laer as die opsporingslimiet.
Serum monsters (n=1692) is van skape, bokke en beeste van vier vermoedelik hoë risiko plase en springbok (Antidorcas marsupialis, n=900) van 29 gemengde boerdery sisteme versamel en getoets vir die teenwoordigheid van Brucella teenliggaampies deur middel van die Rose-Bengal-toets (RBT). Positiewe gevalle is bevestig deur die komplement binding toets (CFT). Die voorkoms van menslike brusellose is bepaal deur 137 abattoir werknemers te toets vir Brucella teenliggaampies deur gebruik te maak van die standaard buis agglutinasie toets (STAT) en die ensiembinding immunosorberende toets (ELISA). Beeste en skape van die vier hoë risiko plase het negatief getoets met die RBT en CFT metodes, maar bokke van twee van die vier plase het seropositief getoets (26/42 en 12/285 onderskeidelik). Nadoodse ondersoek van seropositief bokke het geen patologiese letsels aangedui nie. Die kultuur van orgaanmonsters van seropositief diere vir Brucellae was negatief. Die monsters versamel van wild het negatief getoets deur middel van die RBT en CFT toets metodes. Die voorkoms van brusellose in mense in die studie was geassosieer met die gebruik van ongepasteuriseerde melk, tuisgemaakte bokmelkkaas en koffie met ongepasteuriseerde melk, asook direkte kontak met bokke. Alle abattoir werknemers (n=137) het negatief getoets met die STAT metode, maar drie werknemers het positief getoets met die ELISA metode. Die drie abattoir werkers was klinies normaal en het nie vorige kontak met bevestigde kliniese gevalle gehad nie.
Hierdie studie bevestig die belang van mikrobiologiese, parasitiese en residu monitering as kritieke komponente van 'n gevaar-analise en kritiese kontrolepunt gebaseerde stelsel vir die produksie en verbruik van wildsvleis. Die studie verskaf ʼn basis vir toekomstige navorsing gefokus op ʼn geïntegreerde benadering van mens- en diergesondheid, monitering en vleis veiligheid risiko-analises.
|
Page generated in 0.2689 seconds