( Aepyceros melampus ) R.A. Engels & Prof. L.C. Hoffman - - PowerPoint PPT Presentation

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
• Initial success due to hunting & ecotourism
• Expansion in breeding -› growth in industry
• More stud breeders: stronger genetic selection
• Surplus of splits & inferior colour variants
• Potential for expansion in meat production

Hunting Ecotourism Breeding Meat production

• Fresh meat quality cues:

important for consumer

• Game meat: sustainable resource
• Marketing opportunity for fresh game meat

• Most abundant
• Wide distribution
• Variety of habitats
• Rapid reproductive rate
• Sustainable cropping
• Knowledge of fresh meat quality traits required

24.1 11.8 11.6 52.5 Impala Kudu Springbok Other

Introduction: Impala

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 during the day using .22 or .243 rifles Deboned after 24h: 6 main muscles Physical & chemical analysis Skinned and eviscerated Carcasses hung in cool room (4°C) 11 Male and 11 female impala

Part A: Sex Comparison

Undressed carcass weight (Kg) Dressed carcass weight (Kg) Dressing percentage Shear Force (N) 36.38a 21.55a 59.13a 23.18b 37.80a 21.00a 55.63b 29.75a

Male Female

Male impala: Higher dressing percentage More tender meat No differences:

• Carcass weights
• Muscle weights

Female impala: Higher protein content Redder meat Higher intramuscular fat

a,b,cMean 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 0.85a 0.61c 0.64b 0.18d 0.17de 0.15e Shear force (N) 25.49b 30.14a 31.75a 25.74b 19.19c 23.65b Protein (%) 22.07b 22.90a 22.90a 22.66a 21.50c 21.44c IM fat (%) 1.53b 1.46b 1.81a 1.27c 1.93a 1.51b

Tender: N<43 High protein Low intramuscular fat: <3%

Impala meat

a,b,cMean 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 male impala per production system Harvested during the day using .22 or .243 rifles Skinned and eviscerated Carcasses hung in cool room (4°C) Deboned after 24h: LTL muscles removed Physical, sensory and chemical analysis

Part B: Production System Effect

No significant differences:

• Carcass weights of

intensive vs semi- extensive

• Dressing percentages

37.9 21.9 57.9 35.5 20.7 58.3 46.5 26.6 57.1 10 20 30 40 50 60 70 Undressed carcass weight (Kg) Dressed carcass weight (Kg) Dressing %

Carcass characteristics

Intensive Semi-extensive Extensive

Extensive system:

• Higher carcass weights

Part B: Production System Effect

a ab a a a a b b a 5 10 15 20 25 30 35 L* a* b*

Meat colour

Intensive Semi-extensive Extensive

Intensive Semi- extensive Extensive

No colour differences Darker Less red  Lighter  Redder

Part B: Sensory Analysis

Descriptive Sensory Analysis:

Aroma, flavour, texture & overall eating quality

Undesirable

• Gamey
• Metallic
• Liver-like

Desirable

• Beef-like
• Sweet-

associated

Consumer perspective:

Sample preparation

Part B: Descriptive Sensory Analysis

Parameter Intensive Semi-extensive Extensive Overall aroma intensity 65.1b 66.3b 69.1a Gamey aroma 54.7b 56.1b 58.5a Beef-like aroma 37.2b 38.5b 42.4a Metallic aroma 6.3a 6.0a 2.4b Liver-like aroma 1.8a 2.2a 1.5a Herbaceous aroma 6.8b 8.0b 13.2a Sweet-associated aroma 8.4b 9.5b 11.5a Overall flavour intensity 62.9b 64.2ab 65.7a Gamey flavour 54.0b 55.9a 56.7a Beef-like flavour 39.4b 38.5b 45.0a Metallic flavour 8.4a 8.4a 3.3b Liver-like flavour 1.2b 2.2a 0.6b Herbaceous flavour 7.1b 8.2b 12.1a Sweet-associated taste 10.5b 10.2b 12.6a

Extensive:

• Highest overall aroma & flavour

intensity

• Highest gamey, beef-like,

herbaceous and sweet- associated aromas

• Highest beef-like, herbaceous

flavours and sweet-associated taste

• Lowest metallic aroma & flavour

a,b,cMean values with no common superscript in the same row are

significantly different from each other (P < 0.05)

Intensive vs. Semi-extensive:

• No significant differences except

gamey & liver-like flavour

Part B: Meat quality parameters

Production system Parameter Shear force (N) 52.48a 37.21b 52.33a Protein (%) 22.73b 22.02c 23.38a IM fat (%) 1.97a 1.76b 1.52c

Less tender Moderate protein Highest fat Most tender Lowest protein Moderate fat Less tender Highest protein Lowest fat

Part C

Part C: Post-mortem ageing of meat

5 10 15 20 25 30 2 4 6 8 10 12 14 16 Days aged post-mortem

Meat tenderness & weep loss

Weep loss (%) Shear force (N)

 Optimum ageing period at 4°C: 8 days High weep loss: × Unattractive to consumers Low shear force:  High tenderness  Desirable for consumers No difference between male & female impala

General conclusions

Post-mortem ageing:

• 8 days post-

mortem is

• ptimum

ageing period for ideal meat tenderness Intensive

• Lower gamey &

liver-like flavours

• Highest IM fat

content

• No substantial

advantage i.t.o. carcass yields, meat quality or production Semi-extensive

• Most tender

meat

• Lighter, redder

meat

• Flavour & aroma

attributes similar to intensive system Extensive

• Darker, less

tender meat

• Highest aroma &

flavour intensity

• Highest protein

content

• Lowest IM fat

content

Sex & muscle comparison:

• Male impala

have higher dressing % than females

• All muscles

produce tender meat with high protein & low IM fat

Part B: Production system effect

Part A

Part C

General conclusions

Impala overall:

Desirable physical, sensory & nutritional meat quality traits High dressing percentage (±58%) High protein, low intramuscular fat

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

• Prof. L.C. Hoffman

Fellow postgraduate students Sponsorship of animals Castle de Wildt Financial support NRF SASAS THRIP/SARChI

Thank you! Questions?