Feed supplement and meat preservative potential of grape pomace (Vitis vinifera) in lamb production
| dc.contributor.advisor | Mapiye, Cletos | en_ZA |
| dc.contributor.advisor | Muchenje, Voster | en_ZA |
| dc.contributor.author | Chikwanha, Obert Chenjerayi | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences. | en_ZA |
| dc.date.accessioned | 2019-02-27T13:25:45Z | |
| dc.date.accessioned | 2019-04-17T08:09:53Z | |
| dc.date.available | 2021-02-01T03:00:16Z | |
| dc.date.issued | 2019-03 | |
| dc.description | Thesis (PhDAgric)--Stellenbosch University, 2019. | en_ZA |
| dc.description.abstract | 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. | en_ZA |
| dc.description.abstract | 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. | af_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.embargo.terms | 2020-12-31 | |
| dc.format.extent | (21 unnumbered),216 pages | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/105720 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.subject | Lambs -- Feeding and feeds | en_ZA |
| dc.subject | Antimicrobials | en_ZA |
| dc.subject | Lamb (Meat) -- Quality | en_ZA |
| dc.subject | Grape pomace | en_ZA |
| dc.subject | UCTD | en_ZA |
| dc.title | Feed supplement and meat preservative potential of grape pomace (Vitis vinifera) in lamb production | en_ZA |
| dc.type | Thesis | en_ZA |