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Varietal differences in nutrient, amino acid and mineral composition and in vitro rumen digestibility of grape ( Vitis vinifera ) pomace from the Cape Winelands vineyards in South Africa and impact of preservation techniques
No full textImpact of dehydration on retention of bioactive profile and biological activities of different grape (Vitis vinifera L.) pomace varieties
No full textThe effects of drying method [sun (7 days), oven (72 h at 60 °C) and freeze (∼72 h)] and grape (Vitis vinifera L. cv. Pinotage, Shiraz and Sauvignon Blanc) variety on pomace fatty acid composition, polyphenolic content and antioxidant capacity were evaluated. Furthermore, the influence of sun-dried pomaces on rumen microbial diversity was assessed in vitro. Freeze-dried Shiraz had the highest proportions of 18:1n-9, 18:2n-6, total monounsaturated fatty acid (MUFA), polyunsaturated fatty acids (PUFA) and content of polyphenolics compared to other drying × variety interactions (P ≤ 0.05). Freeze-dried Sauvignon Blanc had the highest proanthocyanidin content and antioxidant activity for both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) relative to other drying × variety interactions (P ≤ 0.05). Regardless of variety and inclusion level, grape pomace variety reduced bacterial species abundance, but improved species diversity, evenness and richness compared to the control (P ≤ 0.05). Overall, freeze-dried Shiraz had the best fatty acid profile and highest polyphenolic content, while freeze-dried Sauvignon Blanc had the highest proanthocyanidin content and antioxidant activity
Cattle production on communal rangelands of South Africa and the potential of acacia karroo in improving Nguni beef production
Get PDFTowards a management database to improve the sustainability of cattle production and its contribution to food security : a case of emerging beef farmers in Limpopo Province, South Africa
Get PDFThesis (MScAgric)--Stellenbosch University, 2017.ENGLISH ABSTRACT: The main objective of the study was to assess and recommend the need for knowledge management strategies to improve sustainability of beef production and its contribution to food security in South Africa. This was achieved by administering structured questionnaires to all the 62 farmers under the Limpopo IDC-Nguni beef cattle project between August and September, 2016. Systemic challenges and constraints affecting the growth and sustainability of the farmers were identified and characterized. A quantitative research approach was used in the study. Data analysis was conducted using descriptive statistics. Farmers indicated that they were constrained with parasites and diseases (89%), feed shortages (86%), water scarcity (82%), poor cattle breeding management (74%) and stock theft (73%). The majority of farmers also reported the challenges of drought (98%), heat waves (97%), rangeland degradation (97%) and biodiversity loss (90%). Location of the farmer was associated with perception of being confronted with production challenges such as poor cattle breeding management (p=0.01), parasites (p=0.02) and diseases (p=0.02). Poor access to markets and marketing information were reported from 76% of the farmers whereas 73% and 45% reported of being confronted by high transaction costs and poor market reliability, respectively. Farmers also reported challenges such as lack of finance (94%) and poor access to extension services (81%). As a follow-up, farmers’ information sources and methods of sharing messages and intervention strategies were assessed. The majority (88%) of farmers sought for management advice when confronted with challenges and constraints. Government extension officers (53%) and other farmers (30%) were indicated as the major sources of information for the farmers. About 80% of the respondents were found to be involved in the creation of interventions and extension messages, of which 63% of them indicated that they shared with other farmers while 33% shared with government extension officials. Majority of the farmers used farm-to-farm visits (56%) when sharing their own created intervention strategies and messages. In addition, 41% of the farmers indicated that they used mobile phones when sharing the intervention messages. The study concludes that the farmers were faced with a variety of challenges and constraints. When faced with challenges, most farmers were involved in the creation of intervention strategies and messages which they shared. Therefore, an opportunity for improved sustainability and food security contribution by the farmers can be explored through development and implementation of knowledge management strategies such as a management database system.
Keywords: Sustainability, challenges and constraints, emerging farmers, management database, intervention strategies, extension messages.AFRIKAANSE OPSOMMING: Die hoofdoel van die studie was om vas te stel wat die behoefte aan kennis bestuurstrategieë rakende die volhoubaarheid van beesvleisproduksie en die bydrae tot voedselsekerheid in Suid-Afrika is, asook aanbevelings te maak oor sulke inligting bestuurstrategieë. Die studie het behels die uitstuur van gestruktureerde vraelyste, van Augustus 2016 tot September 2016, aan die 62 boere wat deel vorm van die Limpopo NOK-Nguni-bees projek. Sistemiese uitdagings en beperkings wat die groei en volhoubaarheid van die boere kon beïnvloed, is geïdentifiseer en gekenmerk. 'n Kwantitatiewe navorsingsbenadering is gebruik in die studie. Data-analise is uitgevoer met behulp van beskrywende statistiek. Boere het aangedui dat hulle vermoë beperk was deur die voorkoms van parasiete en siektes (89%), 'n tekort aan voer (85%), waterskaarste (82%), swak veeteelt bestuur (74%) en veediefstal (73%). Die meerderheid van die boere het ook berig dat uitdagings soos droogte (98%), hittegolwe (97%), agteruitgang van weiding (97%) en verlies aan biodiversiteit (90%) ʼn invloed kan speel. Die ligging van die boer het verband gehou met elkeen se persepsie oor die produksie uitdagings waarmee hulle gekonfronteer is, bv. soos swak veeteelt bestuur (p = 0.01), parasiete (p = 0.02) en siektes (p = 0.02). Swak toegang tot markte en bemarkingsinligting is gesien as beperkend deur 76% van die boere, terwyl 73% en 45% 'n hoë transaksiekoste en swak betroubaarheid van markte, onderskeidelik, as beperkend beskou het. Boere het genoem dat 'n gebrek aan finansies (94%) en swak toegang tot voorligtingsdienste (81%) as uitdagings beskou word. As 'n opvolg fase, is boere se inligtingbronne en metodes van die deel van boodskappe en intervensiestrategieë beoordeel. Die meerderheid boere (88%) het gebruik gemaak van en gesoek vir bestuursadvies wanneer met uitdagings en beperkings gekonfronteer was. Regering voorligtingsbeamptes (53%) en ander boere (30%) is aangedui as die belangrikste bronne van inligting vir dié boere. Sowat 80% van die respondente was gevind om betrokke te wees in die skepping van ingrypings en verspreiding van raad, waarvan 63% van hulle aangedui dat hulle raad met ander boere gedeel het, terwyl 33% raad met voorligtingsbeamptes gedeel het. Die meerderheid van die boere het plaas-tot-plaasbesoeke (56%) as deel van hul eie geformuleerde intervensiestrategieë en oordra van raad gebruik. Daarbenewens het 41% van die boere aangedui dat hulle selfone gebruik om raad en intervensiestrategieë te deel. Die studie kom tot die gevolgtrekking dat die boere in die studie in die gesig gestaar word met 'n verskeidenheid van uitdagings en beperkings. Wanneer boere aan uitdagings en beperkings blootgestel is, het die meeste boere betrokke geraak by die skepping van intervensiestrategieë wat hulle gedeel het. Daar is dus 'n geleentheid om by te dra tot beter volhoubaarheid en voedselsekerheid van die boere deur ontwikkeling en implementering van kennisbestuur strategieë soos ʼn bestuur databasis stelsel.
Sleutelwoorde: Volhoubaarheid, uitdagings en beperkings, opkomende boere, bestuur databasis, intervensiestrategieë, voorligting boodskappe.Master
Beef production, quality and fatty acid composition of non-descript crossbreed steers fed natural pasture-based diets
Get PDFThesis (MScAgric)--Stellenbosch University, 2018.ENGLISH ABSTRACT: The broad objective of the current study was to assess beef production and quality of steers fed
diets formulated using locally available feed resources in communal areas of Eastern Cape
Province, South Africa. A survey to identify locally available feed resources was conducted
using pretested structured questionnaires administered to 47 and 48 participants from Ncorha
and Gxwalibomvu communities, respectively. Crop residues (65% of all respondents), maize
stover in particular, were common in both areas, with more farmers from Ncorha (70%) using
crop residues than those in Gxwalibomvu (59%). Few farmers (<5%) from both communities
used cereal grains and exotic herbaceous legumes (i.e., lucerne) as feed supplements. Farmers
also mentioned that cattle browsed indigenous and exotic leguminous tree species, especially
Acacia mearnsii (Black wattle) during the dry season. Most abundant feed resources in Ncorha
and Gxwalibomvu communities were collected in two seasons and their nutritional
composition analysed. Lucerne hay and A. mearnsii had the overall highest protein in both
seasons while maize grain and natural pasture hay were the overall best energy sources.
Cultivated pasture hay had the highest neutral detergent fibre (NDF), acid detergent fibre
(ADF) and acid detergent lignin (ADL) and consequently had the least in-vitro dry matter
digestibility (IVDMD) compared to feed ingredients. Among the crop-based feed resources,
Glycine max-based commercial ration had the highest crude protein content followed by maize
grain. The growth performance, carcass attributes, meat quality and fatty acid composition of
crossbred steers fed Acacia mearnsii-based, Medicago sativa-based and Glycine max-based
diets were assessed. Thirty-six 12-month-old steers were randomly allocated to the three diets
(n = 12 per treatment) under feedlot conditions for 120 days. The steers fed A. mearnsii-based
diet had lower (P < 0.05) average daily feed intake and average daily gain (ADG) than steers
fed M. sativa-based and G. max-based diets. Steers fed the A. mearnsii-based diet, however,
had a higher (P 0.05) warm and cold carcass weights
followed by those fed the G. max-based and A. mearnsii-based diets, respectively. The G. maxbased and M. sativa-based diets had positive effects on growth performance and carcass
characteristics of the steers compared to the A. mearnsii-based diet. Diet had no effect (P >
0.05) on meat colour (L*, a*, b*, chroma and hue), pH, temperature, drip loss, shear force,
crude protein and fat. Meat from steers finished on A. mearnsii-based diets had higher (P ≤
0.05) moisture and ash content than meat from those finished on G. max-based and M. sativabased diets. Meat from steers fed A. mearnsii-based diets had the highest cooking losses
followed by those fed and M. sativa- and G. max-based diets, respectively (P ≤ 0.05). Meat
from steers fed the M. sativa-based diet had higher (P ≤ 0.05) proportions of individual and
total SFA and (n-) 3 PUFA and lower (P ≤ 0.05) proportions of linoleic acid and total n-6 PUFA
than G. max and A. mearnsii- based diets. Steers finished on A. mearnsii-based diet had lower
feedlot performance, greater gross margins, better n-3 PUFA profile and comparable meat
quality to those finished on M. sativa- and G. max-based diets. The M. sativa-based diet had
better potential to be used as alternative feeding resources for finishing cattle in a conventional
feedlot system than the A. mearnsii-based diet.AFRIKAANSE OPSOMMING: Geen opsommingMaster
Sustainability of smallholder cattle production and its vertical integration into the formal beef market value chain in South Africa
Get PDFThesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: A survey to assess the sustainability and marketing opportunities for smallholder cattle production systems was conducted by consulting with a total of 95 smallholder cattle producers in Ncorha and Gxwalibomvu communities in the Eastern Cape Province (ECP) of South Africa. In addition, a total of 18 surrounding beef retailers, 5 abattoirs that supplied beef to these retailers and 155 beef consumers who bought beef from these retailers between February 2013 and February 2014 were also interviewed using pretested structured questionnaires. The surveys established the perception of beef traders and consumers on the development of a Natural beef (NB) brand and indicated the willingness of participants to support the development of a NB brand. The results indicated that a smallholder beef cattle production system was socially and environmentally conditionally sustainable but economically not sustainable. Overall, the system was conditionally sustainable. Cattle herd size was bigger in Ncorha than in Gxwalibomvu (13.7±1.9 vs. 11.3 ± 1.9 heads of cattle, respectively). Smallholder producers from both sites sold an average of two cattle per year. Young farmers (40 years old), traditionalists and larger households (>5 members). Similarly, households with access to extension services, owners of smaller cattle herds ( 40 jaar oud), tradisionele boere en groter huishoudings (> 5 lede). Net so het huishoudings met toegang tot voorligtingsdienste, eienaars van klein troppe (<10 beeste) en boere wat aan die laer inkomstegroep behoort het (<R3000), ʼn groter potensiaal gehad om vee te verkoop. Meer as 70% van verbruikers was bereid om vir 'n NPB produk te betaal sodra dit beskikbaar is op die mark, maar was nie bereid om 'n premie vir die NPB handelsmerk te betaal nie. Verbruikers se bereidwilligheid om NPB produkte te koop en ʼn premie te betaal vir die handelsmerk was deels beïnvloed deur geslag, ouderdom, bron van inkomste en die meeste deur vleis voorkeur en frekwensie van vleis verbruik. Kleinhandelaars was nie bereid om deel te neem aan die ontwikkeling van ʼn NPB handelsmerk nie. Bees handelaars het egter voorgestel dat kommunale voerkrale, groepsbemarking en karakterisering van vleis van beeste gevoer op natuurlike weiding om die unieke kwaliteitseienskappe van die tipe vleis vas te stel, potensieel afsette en ekonomiese volhoubaarheid van kleinboere produksie beeste stelsels kan verbeter. Die studie het bevind dat kleinboer veeproduksiestelsels in die Oos-Kaap Provinsie voorwaardelik volhoubaar is en dat geleenthede vir die integrasie van kleinboer beesprodusente in die formele vleisbeesmark waardeketting in die karakterisering van beesvleis geproduseer op natuurlike weiding, voerkrale en groepsbemarking, vervat is.Master
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Feed supplement and meat preservative potential of grape pomace (Vitis vinifera) in lamb production
Get PDFThesis (PhDAgric)--Stellenbosch University, 2019.ENGLISH ABSTRACT: The objective of the overall study was to evaluate the potential of grape (Vitis vinifera L.) pomace
(GP) as a feed supplement and meat preservative in lamb production. Pomace from two red grape
(Pinotage and Shiraz) varieties and one white grape variety (Sauvignon Blanc), were collected
from the Welgevallen cellar to evaluate the effect of drying method [sun (7 d), oven (60 °C for 72
h) and freeze] on the nutrient composition and in vitro ruminal neutral detergent fiber (ivNDF)
digestibility. Overall, sun- and oven-dried Shiraz GP were characterized by a higher dry matter,
crude protein, NDF, acid detergent fiber and lignin content, compared to the other drying × variety
combinations. Freeze- and oven-dried Pinotage GP were characterized by the highest mineral
content, compared to freeze-dried Pinotage GP that had the most comprehensive amino acid profile
and highest ivNDF digestibility at 24 and 48 h for both parameters and time periods. The second
study assessed the impact of drying method on the retention of bioactive compounds and biological
activities of the three types of GP. Freeze-dried Sauvignon Blanc GP had the highest
proanthocyanidin content and exhibited the highest antioxidant activity relative to other drying ×
variety combinations. Overall, freeze-dried Shiraz GP had the most comprehensive fatty acid
profile and highest phenolic content compared to other treatment combinations. Based on the
nutrient composition, the low proanthocyanidin content, the availability and the fact that it is a
unique South African cultivar, Pinotage GP was selected for subsequent trials. The effect of
supplementing sun-dried Pinotage GP on nutrient utilization in finisher lambs was evaluated.
Twenty-one Dohne Merino lambs [51.6 ± 4.70 kg body weight (BW)] were randomly assigned to
a control diet group (no GP), and two treatments groups containing 100g and 200 g GP/kg diet dry
matter (DM), respectively. Increasing the inclusion level of Pinotage GP in the lamb finisher diet
resulted in a linear decline in carbohydrate intake, total volatile fatty acid concentration, microbial
nitrogen (N) yield, and total purine derivatives excreted. No adverse effects on retention and
efficiency of N utilization were observed with the GP-containing diets. A follow up study assessed the effect of sun-dried Pinotage GP supplementation in lamb diets on growth performance, and
carcass traits and meat quality attributes. Forty Dohne Merino lambs (32 ± 1.7 kg BW) were
randomly assigned to five experimental diets that comprised a control (no GP), and four GP-based
diets consisting of 50, 100, 150 and 200 g GP/ kg, respectively. Dry matter intake (DMI), average
daily gain (ADG) and carcass traits for lambs were influenced by the addition of GP without
negatively affecting meat quality traits. The optimum inclusion levels of GP for DMI and ADG
were observed at 113g/kg and 96 g/kg, respectively. The last experiment evaluated the sensory
quality and shelf life of retail displayed meat of lambs fed increasing levels (i.e., 0, 50, 100, 150
and 200 g GP/kg). Overall, the 150 and 200 g GP/kg diets resulted in higher antioxidant activity,
and reduced lipid and protein oxidation occurring during retail display, compared to the 0 to 100
g GP/kg diets. Microbial loads increased during the retail display, but at a lower rate for the 150
and 200 g GP/kg diets. Diet had no negative organoleptic effect on the sensory quality of the lamb.
Overall, the inclusion of GP improved production and shelf life without compromising meat
physicochemical and sensory qualities. Based on the experimental evidence, it can be concluded
that GP can be used as an alternative supplement and meat preservative by the red meat industry.AFRIKAANSE OPSOMMING: Die doelwit van die algehele studie was om die potensiaal van druiwe (Vitis vinifera L.) vrugtepulp
(GP) as 'n voedingsaanvulling en vleisbeskermingsmiddel in lamsvleis produksie te evalueer. Die
vrugtepulp twee rooi druif kultivars (Pinotage en Shiraz) en een wit druif kultivar (Sauvignon
Blanc) is verkry van die Welgevallen kelder om die effek van droogmetode [son (7 d), oond (60
°C vir 72 h) en vries] op die voedingstofsamestelling en in vitro vertering van ruminale neutrale
detergent vesel (ivNDF) te evalueer. In die geheel, is son- en oondgedroogde Shiraz-GP
gekenmerk deur 'n hoër droë materiaal, ruproteïen, NDF, suur-detergent vesel en lignieninhoud,
in vergelyking met die ander droogmetode × kultivar kombinasies. Vries- en oondgedroogde
Pinotage-GP is gekenmerk deur die hoogste mineraalinhoud, in vergelyking met die vriesdroogde
Pinotage-GP wat die mees omvattende aminosuurprofiel gehad het en die hoogste IVNDF
verteerbaarheid op 24 en 48 uur vir beide parameters en tydperke getoon het. Die tweede studie
het die impak van droogmetode op die behoud van bio-aktiewe verbindings en biologiese
aktiwiteit van die drie soorte GP ondersoek. Gevriesdroogde Sauvignon Blanc GP het die hoogste
pro-antosianidieninhoud gehad en het die hoogste antioksidant aktiwiteit getoon, relatief tot die
ander droogmetode × kultivar kombinasies. In die geheel het gevriesdroogde Shiraz GP die mees
omvattende vetsuurprofiel en die hoogste fenoliese inhoud in vergelyking met ander
behandelingssamestellings gehad. Gebaseer op die voedingstofsamestelling, die lae pro antosianidieninhoud, die beskikbaarheid en die feit dat dit 'n unieke Suid-Afrikaanse kultivar is, is
Pinotage-GP gekies vir verdere proewe. Die effek van die aanvulling van die songedroogde
Pinotage GP op die voedingstof metabolisme van afrond lammers is evalueer. Een-en-twintig
Dohne Merino-lammers [51.6 ± 4.70 kg liggaamsgewig (BW)] is ewekansig toegewys aan 'n
kontrole-dieetgroep (geen GP) en twee behandelingsgroepe, wat onderskeidelik 100 g en 200 g
GP/kg dieet droë materiaal (DM) bevat het. Die verhoging van die insluitingsvlak van Pinotage
GP in die lam afrond dieet het gelei tot 'n lineêre afname in koolhidraat inname, totale vlugtige vetsuur konsentrasie, mikrobiese stikstof (N) opbrengs en totale purien afgeleides. Geen nadelige
effekte op behoud en doeltreffendheid van N-benutting is waargeneem met die GP-bevattende
dieet nie. 'n Opvolgstudie het die effek van son-gedroogde Pinotage-GP-aanvulling in lam diëte
beoordeel op grond van groeiprestasie, karkas eienskappe en vleiskwaliteit. Veertig Dohne
Merino-lammers (32 ± 1.7 kg BW) is ewekansig toegewys aan vyf eksperimentele diëte wat
bestaan uit 'n kontrole dieet (geen GP) en vier GP-gebaseerde diëte wat onderskeidelik die
insluiting van 50g, 100g, 150g en 200 g GP/kg behels het. Droë materiaal inname (DMI),
gemiddelde daaglikse gewigstoename (ADG) en karkas eienskappe vir lammers is beïnvloed deur
die insluiting van GP, sonder om vleisgehalte eienskappe negatief te beïnvloed. Die optimum
insluiting vlakke van GP vir DMI en ADG is waargeneem teen onderskeidelik 113g/kg en 96g/kg
insluitingsvlakke. Die laaste eksperiment het die sensoriese kwaliteit en die rakleeftyd van
kleinhandelsnitte van lammers evalueer wat diëte aangevul met toenemende vlakke (d.w.s. 0g,
50g, 100g, 150g en 200 g GP/kg) ontvang het. In die geheel het die 150g- en 200 g GP/kg diëte
tot hoër anti-oksidante aktiwiteit gelei, en verminderde lipied- en proteïen-oksidasie tydens
kleinhandel vertoon, in vergelyking met die 0g tot 100 g GP/kg dieet. Mikrobiese tellings het
gedurende die kleinhandel vertoontydperk toegeneem, maar teen 'n laer tempo vir die 150g- en
200 g GP/kg diëte. Dieet het geen negatiewe organoleptiese effek op die sensoriese kwaliteit van
die lamsvleis gehad nie. Die oorhoofse studie het bevind dat die insluiting van GP tot verbeterde
produksie en rakleeftyd bygedra het sonder om die vleis se fisiese en sintuiglike eienskappe te
benadeel. Op grond van die eksperimentele bewyse kan daar tot die gevolgtrekking gekom word
dat GP as 'n alternatiewe aanvulling en vleisbeskermende middel deur die rooivleisbedryf gebruik
kan word.Doctora
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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