MEAT PRODUCTION POTENTIAL OF IMPALA ( Aepyceros melampus ) R.A. Engels & Prof. L.C. Hoffman
Introduction • Game farming - a successful enterprise • Game animals:
Introduction Game industry is based on four pillars • Hunting Initial success due to hunting & ecotourism • Expansion in breeding - › growth in industry • Ecotourism More stud breeders: stronger genetic selection • Surplus of splits & inferior colour variants • Potential for expansion in meat production • Breeding Game meat: sustainable resource • Marketing opportunity for fresh game meat • Meat Fresh meat quality cues: • production important for consumer
Introduction: Impala • Most abundant 24.1 Impala • Wide distribution Kudu 52.5 • Variety of habitats Springbok 11.8 Other • Rapid reproductive rate 11.6 • Sustainable cropping • Knowledge of fresh meat quality traits required Problem Many factors not yet quantified Required to increase meat production •
Research Aim To quantify factors influencing impala meat quality:
Experimental locations
Part A
Part A: Methodology Harvested 11 Male and during the day Skinned and 11 female using .22 or eviscerated impala .243 rifles Physical & Deboned after Carcasses chemical 24h: 6 main hung in cool analysis muscles room (4°C)
Part A: Sex Comparison No differences: Undressed Dressed Dressing Shear Force Carcass weights • carcass carcass percentage (N) Muscle weights • weight (Kg) weight (Kg) Male impala: Male Higher dressing percentage 36.38 a 21.55 a 59.13 a 23.18 b More tender meat Higher intramuscular fat Female impala: Female 37.80 a 21.00 a 55.63 b 29.75 a Higher protein content Redder meat a,b,c Mean values with no common superscript in the same column are significantly different from each other (P < 0.05)
Part A: Muscle Comparison Parameter Muscle type Hindquarter Forequarter LTL BF SM ST IS SS Weight 0.85 a 0.61 c 0.64 b 0.18 d 0.17 de 0.15 e Shear force (N) 25.49 b 30.14 a 31.75 a 25.74 b 19.19 c 23.65 b Protein (%) 22.07 b 22.90 a 22.90 a 22.66 a 21.50 c 21.44 c IM fat (%) 1.53 b 1.46 b 1.81 a 1.27 c 1.93 a 1.51 b Tender: N<43 Impala High protein meat Low intramuscular fat: <3% a,b,c Mean values with no common superscript in the same row are significantly different from each other (P < 0.05)
Part B
Part B: Production Systems All impala harvested at ±15 months of age
Part B: Methodology 12 Sub-adult Harvested male impala per during the day Skinned and production using .22 or eviscerated system .243 rifles Deboned after Physical, Carcasses hung 24h: sensory and in cool room chemical LTL muscles (4°C) analysis removed
Part B: Production System Effect Carcass characteristics Extensive system: 70 Higher carcass weights 58.3 • 57.9 57.1 60 46.5 50 No significant differences: 37.9 35.5 40 Carcass weights of • 26.6 30 21.9 intensive vs semi- 20.7 20 extensive 10 Dressing percentages • 0 Undressed carcass Dressed carcass weight Dressing % weight (Kg) (Kg) Intensive Semi-extensive Extensive
Part B: Production System Effect Semi- Meat colour Extensive Intensive extensive a 35 a 30 b 25 20 a 15 ab b a 10 a a 5 0 Darker No colour L* a* b* Less red differences Intensive Semi-extensive Extensive Lighter Redder
Part B: Sensory Analysis Descriptive Sensory Analysis: Consumer perspective: Aroma, flavour, texture & overall eating quality Desirable Undesirable • Beef-like • Gamey • Sweet- • Metallic associated • Liver-like Sample preparation
Part B: Descriptive Sensory Analysis Extensive: Parameter Intensive Semi-extensive Extensive Highest overall aroma & flavour • 65.1 b 66.3 b 69.1 a Overall aroma intensity intensity Gamey aroma 54.7 b 56.1 b 58.5 a Highest gamey, beef-like, • 37.2 b 38.5 b 42.4 a Beef-like aroma herbaceous and sweet- Metallic aroma 6.3 a 6.0 a 2.4 b 1.8 a 2.2 a 1.5 a Liver-like aroma associated aromas Herbaceous aroma 6.8 b 8.0 b 13.2 a Highest beef-like, herbaceous • 8.4 b 9.5 b 11.5 a Sweet-associated aroma flavours and sweet-associated 62.9 b 64.2 ab 65.7 a Overall flavour intensity taste Gamey flavour 54.0 b 55.9 a 56.7 a 39.4 b 38.5 b 45.0 a Beef-like flavour Lowest metallic aroma & flavour • Metallic flavour 8.4 a 8.4 a 3.3 b Intensive vs. Semi-extensive: 1.2 b 2.2 a 0.6 b Liver-like flavour Herbaceous flavour 7.1 b 8.2 b 12.1 a No significant differences except • 10.5 b 10.2 b 12.6 a Sweet-associated taste gamey & liver-like flavour a,b,c Mean values with no common superscript in the same row are significantly different from each other (P < 0.05)
Part B: Meat quality parameters Production system Parameter Shear force (N) 52.48 a 37.21 b 52.33 a Protein (%) 22.73 b 22.02 c 23.38 a IM fat (%) 1.97 a 1.76 b 1.52 c Less tender Most tender Less tender Moderate protein Lowest protein Highest protein Highest fat Moderate fat Lowest fat
Part C
Part C: Post-mortem ageing of meat Meat tenderness & weep loss No difference between male & female impala Weep loss (%) Shear force (N) 30 25 High weep loss: 20 × Unattractive to consumers 15 10 Low shear force: 5 High tenderness 0 Desirable for consumers 0 2 4 6 8 10 12 14 16 Days aged post-mortem Optimum ageing period at 4°C: 8 days
General conclusions Part B: Production system effect Part C Part A Sex & muscle Post-mortem Intensive Semi-extensive Extensive comparison: ageing: • Lower gamey & • Most tender • Darker, less • Male impala • 8 days post- liver-like flavours meat tender meat have higher mortem is • Highest IM fat • Lighter, redder • Highest aroma & dressing % than optimum content meat flavour intensity females ageing period • No substantial • All muscles • Flavour & aroma • Highest protein for ideal meat produce tender advantage i.t.o. attributes similar content tenderness meat with high carcass yields, to intensive • Lowest IM fat protein & low IM meat quality or system content fat production
General conclusions Impala overall: Desirable physical, High protein, High dressing sensory & low percentage nutritional intramuscular (±58%) meat quality fat traits
Recommendations • Repetition of the experiment with impala of different age groups (sub-adult vs. adult) • Investigate the effect of different diets/biomes on sensory meat quality • Compare different cropping methods to evaluate ante-mortem stress effect on meat quality & production
Acknowledgements Support, advice & assistance Sponsorship of animals Financial support Prof. L.C. Hoffman Castle de Wildt NRF Fellow postgraduate students SASAS THRIP/SARChI
Thank you! Questions?
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