Yield and meat quality attributes of wild fallow deer (Dama Dama) in South Africa

Fitzhenry, Leon Brett (2016-03)

Thesis (MSc)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: Fallow deer (Dama dama), although not native to South Africa, are abundant in the country and could contribute to domestic food security and economic stability. Nonetheless, this wild ungulate remains overlooked as a protein source and no information exists on their production potential and meat quality in South Africa. The aim of this study was thus to determine the carcass characteristics, meat- and offal-yields, and the physical- and chemical-meat quality attributes of wild fallow deer harvested in South Africa. Gender was considered as a main effect when determining carcass characteristics and yields, while both gender and muscle were considered as main effects in the determination of physical and chemical meat quality attributes. Live weights, warm carcass weights and cold carcass weights were higher (p < 0.05) in male fallow deer (47.4 kg, 29.6 kg, 29.2 kg, respectively) compared with females (41.9 kg, 25.2 kg, 24.7 kg, respectively), as well as in pregnant females (47.5 kg, 28.7 kg, 28.2 kg, respectively) compared with non-pregnant females (32.5 kg, 19.7 kg, 19.3 kg, respectively). Accordingly, dress-out percentages were higher (p < 0.05) in males (61.5%) than females (59.0%). Total consumable offal (excluding stomach and intestines) comprised ca. 9% of the fallow deer live weights, although gender and pregnancy influenced (p < 0.05) some individual organ weights and yields. The weights of seven muscles (longissimus thoracis et lumborum [LTL], infraspinatus [IS], supraspinatus [SS], biceps femoris, [BF], semimembranosis [SM], semitendinosus [ST] and psoas major [PM]) did not differ (p > 0.05) with gender, with the LTL and BF being the heaviest. Total meat and bone weights were higher (p < 0.05) for males (20.4 kg and 9.1 kg, respectively) than for females (16.0 kg and 6.9 kg, respectively), but no gender differences were found for the meat-to-bone ratios (2.2–2.3). Physical meat quality measurements and proximate analyses were conducted on six different muscles (LTL, BF, SM, ST, IS and SS) from male (n = 6) and female (n = 6) fallow deer. Ultimate pH (pHu), drip loss, cooking loss and shear force values were influenced (p < 0.05) by muscle, but not by gender. Mean pHu readings ranged from 5.4 to 5.6 in the six muscles, while drip loss, cooking loss and shear force values ranged from 1.3–1.6%, 29.4–36.1% and 31.3–61.9 N, respectively. In terms of colour, the fallow deer muscles were characterised by L* < 40, high a* and low b* values, being in line with the values generally desired by venison meat consumers. Muscle, however, had an effect (p < 0.05) on all the measured colour parameters (L*, a*, b*, chroma, hue-angle), whereas gender only influenced (p < 0.05) the a* and chroma values in certain muscles. The proximate composition of the six fallow deer muscles ranged from 73.3–76.2% moisture, 20.4–23.1% protein, 2.2–3.2% lipid and 1.1–1.5% ash. The concentrations of all the proximate components were influenced (p < 0.05) by muscle, but not by gender. Fatty acid (FA) and mineral analyses were conducted on two fallow deer muscles, namely the LTL and BF. Polyunsaturated fatty acids (PUFAs) were found to be the major class of FAs in the muscles (ca. 13.57 mg/g meat), followed by saturated FAs (SFAs; ca. 10.20 mg/g meat) and monounsaturated FAs (MUFAs; ca. 6.46 mg/g meat). Linoleic acid (C18:2n6) and arachidonic acid (C20:4n6) made up the largest proportions of the PUFAs, while stearic acid (C18:0) and palmitic acid (C16:0) were the main SFAs measured. Nonetheless, the PUFA content was influenced (p < 0.05) by muscle (BF > LTL), the MUFA content was influenced (p < 0.05) by gender (female > male), and a significant (p < 0.05) muscle  gender interaction was observed for the SFAs. Overall, the fallow deer muscles had favourable PUFA/SFA ratios (> 0.4) and omega-6/omega-3 (< 4) ratios and could thus be considered as healthy lipid sources. The main essential macro-minerals measured in the LTL and BF were potassium, phosphorus, sodium and magnesium, while iron, zinc and copper represented the primary micro-minerals. The mineral concentrations appeared to be influenced more by muscle than by gender. This study represents the first attempt to quantify the yields and meat quality attributes of wild fallow deer in South Africa, the results of which should lay a foundation for the enhanced utilisation, promotion and consumer acceptance of the derived products.

AFRIKAANSE OPSOMMING: Die takbok (Dama dama) is nie inheems tot Suid-Afrika nie, maar wel volop teenwoordig en kan daarom ‘n groot bydrae lewer tot voedselsekerheid en die land se ekonomiese stand. Nie te min word die waarde van hierdie wildspesie, as bron van proteïen, dikwels oor die hoof gesien. Tot op hede is daar ook geen inligting rakende die produksiepotensiaal en vleiskwaliteit van hierdie spesie in Suid-Afrika te vinde nie. Daarom was die doel van hierdie studie om die karaktereienskappe, vleis- en afval-opbrengs, asook die fisiese en chemiese vleiskwaliteitseienskappe, van takbokke in Suid-Afrika te bepaal. Geslag is beskou as die hoofeffek in terme van die karkaseienskappe en opbrengste terwyl beide geslag en spiertipe gesien is as die hoofeffekte in die bepaling van die fisiese en chemiese vleiskwaliteitseienskappe. Die lewendige massa, warm karkas massa en koue karkas massa was hoër (p < 0.05) in die manlike diere (47.4 kg, 29.6 kg, 29.2 kg, onderskeidelik) in vergelyking met die vroulike diere (47.5 kg, 28.7 kg, 28.2 kg, onderskeidelik), so ook in die dragtige takbokke (32.5 kg, 19.7 kg, 19.3 kg, onderskeidelik) teenoor die nie-dragtige takbokke (32.5 kg, 19.7 kg, 19.3 kg, onderskeidelik). Die uitslagpersentasies was ook hoër (p < 0.05) in die manlike (61.5%) as die vroulike (59.0%) takbokke. Die totale eetbare afval (uitsluitend maag en ingewande) beslaan ongeveer 9% van die lewende gewig. Geslag en dragtigheid het wel die individuele orgaan massas en opbrengste beïnvloed. Die massas van die sewe spiere (longissimus thoracis et lumborum [LTL], infraspinatus [IS], supraspinatus [SS], biceps femoris, [BF], semimembranosis [SM], semitendinosus [ST] and psoas major [PM]) het nie verskil (p > 0.05) as gevolg van geslag nie en die LTL en BF was die swaarste spiere. Die totale massa van die vleis en bene was hoër by die manlike takbokke (20.4 kg en 9.1 kg, onderskeidelik) as by die vroulike takbokke (16.0 kg en 6.9 kg, onderskeidelik), alhoewel daar geen verskil was in die vleis tot been verhoudings nie (2.2–2.3). Die fisiese vleiskwaliteit en proksimale samestelling is bepaal op ses verskillende spiere (LTL, BF, SM, ST, IS and SS) van manlike (n = 6) en vroulike (n = 6) takbokke. Die finale pH (pHu), dripverlies, kookverlies en instrumentele sagtheid is beïnvloed (p < 0.05) deur spiertipe, maar nie deur geslag. Die gemiddelde pHu varieer van 5.4 tot 5.6 in die ses spiere, terwyl die persentasies dripverlies, kookverlies en instrumentele sagtheid strek van 1.3–1.6%, 29.4–36.1% en 31.3–61.9%, onderskeidelik. Die kleur van die takbokvleis toon L* < 40, hoë a* en lae b* waardes wat ooreenstem met die kenmerkende kleur van wildsvleis. Spiertipe het wel ‘n invloed gehad op al die kleur parameters (L*, a*, b*, chroma, hue), terwyl geslag net die a* en chroma waardes van sekere spiere geaffekteer het. Die proksimale analise van die ses spiere het getoon dat takbokvleis bestaan uit 73.3–76.2% vog, 20.4–23.1% proteïen, 2.2–3.2% lipied, en 1.1–1.5% as. Die persentasie van al die proksimale komponente is beïnvloed (p < 0.05) deur spiertipe, maar nie deur geslag nie. Vetsuur en mineraal analises is uitgevoer op slegs twee van die takbok spiere naamlik die LTL en BF. Die spiere het hoofsaaklik bestaan uit poli-onversadigde vetsure (PUFAs) (ongeveer 13.57 mg/g vleis) gevolg deur versadigde vetsure (SFAs; ongeveer 10.20 mg/g vleis) en mono-onversadigde vetsure (MUFAs; ongeveer 6.46 mg/g vleis). Linoleïensuur (C18:2n6) en aragidoonsuur (C20:4n6) is die individuele vetsure wat hoofsaaklik bygedra het tot die hoë PUFA vlakke terwyl steariensuur (C18:0) en palmitiensuur (C16:0) die hoof SFAs teenwoordig was. Die PUFA inhoud is beïnvloed (p < 0.05) deur spiertipe (BF > LTL), die MUFA inhoud deur geslag (vroulik > manlik) en ‘n betekenisvolle spiertipe x geslag interaksie is gevind rakende die SFA inhoud. In geheel het al die spiere gunstige PUFA/SFA verhoudings (> 0.4) asook omega-6 tot omega-3 verhoudings (< 4) en kan dus gesien word as gesonde bronne van vet. Die hoof essensiële makrominerale in die LTL en BF was kalium, fosfaat, natrium en magnesium terwyl yster, sink en koper die primêre mikrominerale teenwoordig was. Dit wil voorkom of die konsentrasie minerale meer deur spiertipe as deur geslag beïnvloed word. Hierdie studie verteenwoordig die eerste poging om die opbrengs en vleiskwaliteit van wilde takbokke in Suid-Afrika te kwantifiseer. Die resultate bied ‘n platform om sodoende die aanwending en verbruikers aanvaarding van takbokvleis te bevorder.

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