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Department Animal Sciences•
Faculty of AgriSciences
The yield and nutritional value of meat from African ungulates, camelidae,
rodents, ratites and reptiles
Louw HoffmanDepartment of Animal Sciences
Stellenbosch University
14 August 2008
2
Outlay of presentation
•
Background•
Ungulates from Africa
•
Camelids•
Rodents
•
Ratites•
Reptiles
•
Conclusion
3
Introduction
• A given
• Land available for agriculture (livestock) limited
•
Rainforest clearing?•
Utilize available land more efficiently
•
Genetic selection•
Improved nutrition
•
Better management
•
Utilize marginal land using species adapted to these conditions
4
Marginal land
5
Introduction
• Mini-Livestock breeding & farming
Backyard family production –
food securityAfrica
cane, rat, giant rat, porcupineLatin America
Agouti, coypu, paca, guinea pig
Edible frogs, reptiles, birds•
Factors suitable for successful production also threat
Breeding, adaptability e.g. nutria
• Legality issues
6
Introduction
• Although mini-livestock production to formal world meat production is small
• Important source of protein in rural areas
•
Bushmeat
Bowen-Jones, E. 1997-98 (distributed 1999). 'A review of the commercial bushmeat trade with emphasis on Central/West Africa and the great apes.' African Primates 3(1-2): Supplement 1-42.
7
Introduction
• Increase in the requirement for non-traditional / unconventional meat/protein sources by the modern consumer
•
Tourists : “African experience”•
International travel –
expand
• Import (legal / illegal?) into EU
•
Health consciousness•
Global village –
cosmopolitan society
•
“Home away from home”
8
Introduction
• Health issue: diet of pre-agricultural man predominately phospholipids
•
Free living animals –
low fat rich in linoleic
& linolenic acids
• Data readily available for fatty acid profile of farmed species
• Limited for wild animals consumed formal / bush meat or for farmed species not readily consumed in the Western world
• Paucity of information on other nutrients
•
Amino acids, •
Minerals
•
Vitamins
9
Introduction
• Number of NGO’s, Governments, private enterprises identified these niche markets.
•
Production systems realized•
Minimizes threat of over exploitation
• Data on nutritional composition (and other meat quality attributes) required by these markets
• Objective: Reviews data available on some of the alternative species being farmed / harvested sustainably (southern hemisphere)
•
fatty acids –
healthy alternative•
“quality life”
10
Ungulates from Africa
•
Reviewed: Hoffman & Wiklund
(2005)•
Most species: ruminants•
Factors effecting f/a composition has been reviewed•
Two papers in Meat Science in 2008
•
Some species that will be discussed:•
Duiker (Sylvicapra
grimmia)•
Springbuck (Antidorcas marsupialis)•
Blesbok (Damaliscus
pygargus)•
Gemsbuck
(Oryx gazella)•
Kudu (Tragelaphus strepsiceros)•
Blue wildebeest (Connochaetes
taurinus)
11
Duiker (Sylvicapra
grimmia)
•
Grey duiker & forest duiker•
Size of a lamb
•
Two papers on meat composition
deboned hind quarters
12
Springbok (Antidorcas marsupialis)
•
Intensive study on the effects of region, age and gender
•
Major species hunted•
Major species exported (RSA & Namibia)•
Region•
Age•
Gender•
yields,•
Chemical composition •
proximate, f/a, mineral, amino acids•
Sensory
Sausage / sosatie
13
Means for cholesterol, SFA, MUFA, PUFA (mg/100g), P:S and n-6:n-3 ratio with region and age as main effects
REGION AGE
GARIEP WILLEM P ADULT SUB-ADULT
Cholesterol 59.3 54.5 55.0 59.3 SFA 4.63 3.37 4.51 3.57 MUFA 2.58 1.45 2.45 1.65 PUFA 4.61 a 3.21 b 3.94 3.82 PUFA n-6 3.35 a 2.37 b 2.92 2.77 PUFA n-3 1.12 a 0.73 b 0.90 0.92 P:S 1.18 0.96 0.97 1.13 n-6/n-3 3.02 3.35 3.34 3.08
14
Sensory correlations
•
Relationships between sensory and chemical, physical attributes of the meat was tested in a set of linear regressions.
•
Inverse correlation -
shear force (kg/1.27 cm diameter) and tenderness (r = -0.70, p < 0.01).
•
Similar correlation coefficient (r = -0.70) lambs (Devine et al., 1993).
•
Shear force -
connective tissue residue (r = -0.68, p < 0.01) -
sustained juiciness (r = -0.43, p = 0.05).•
No significant (p < 0.05) correlation was observed between the IMF content & meat juiciness •
→ result of the low IMF content (< 4%) of springbok meat
•
High levels of PUFA’s
→ gamey flavour (Swanson & Penfield, 1991).
•
α
-
linolenic
acid (C18:3 n-3) (r = 0.47, p< 0.05)
15
Conclusion
•
Springbok is low in fat (< 4%); P:S ratio above 0.45; PUFA n-6:n-3 ratio below the recommended maximum.
•
The major fatty acid of springbok meat is stearic acid (SFA) and this fatty acid does not have serum
cholesterol highering
attributes in vitro.•
Important attribute -
health conscious consumer’s
diet.
16
Blesbok (Damaliscus
pygargus)
•
Effect of region & sex•
Region had an effect (P<0.05) on lipid (1.01%) and individual amino acid contents.
•
The saturated fatty acids palmitic
acid (16.36%) and stearic
acid (26.08%) were found to be the main fatty acids in blesbok meat. Blesbok meat has a ratio of polyunsaturated to saturated fatty acids of 0.92.
•
Cholesterol content (52.76 mg100 g1 edible portion) is similar to that of other red meat species
Louwrens C. Hoffman, Karen Smit, Nina Muller. Chemical characteristics of blesbok (Damaliscus dorcas phillipsi) meat. Journal of Food Composition and Analysis 21 (2008) 315–319
Potjie
17
Gemsbuck
(Oryx gazella)
•
Important export species from Namibia•
Data being analyzed
steaks
18
Kudu (Tragelaphus strepsiceros)
•
Gender -
no effect on chemical composition•
Manuscript in preparation using larger sample size•
Gender•
Age•
Impala
carpaccio
19
Blue wildebeest (Connochaetes
taurinus)
•
Manuscript in preparation•
Perceived to be tough
fillet
20
Camelids
•
family camelidae•
Genera:•
Camelus -
two species •
Camelus dromedarius
(one-hump camel) constitute about 91% of all the camels
•
Camelus bacterium•
Lama
-
four species •
Lama glama,•
Lama pacos
(now changed to Vicugna
pacos
L. as proposed by Kadwell
et al., 2001), •
Lama guanicoe
and •
Vicugna
vicugna.
21
Camelus dromedarius
(one-hump camel)
•
Dresses out: 55.8%•
Slaughter weight: 456kg
•
Meat quality attributes similar to beef•
Effect of age•
Tougher, fatter, etc.
22
Hump
•
13% of carcass weight•
adipose tissue : 84% lipid and 139 mg cholesterol per 100g wet weight and 166 mg cholesterol per 100g lipid (Abu-Tarboush
& Dawood, 1993)
. •
The hump frequently forms part of the sirloin cut•
a high lipid content (49% fat) as most of the camel fat is deposited in the hump rather than being distributed throughout the body
•
Insulate from solar radiation
Kadim, I. T., Mahgoub, O. & Purchas, R. W. (2008). A review of the growth, and of the carcass and meat quality characteristics of the one-humped camel (Camel dromedarius). Meat Science, doi:10.1016/j.meatsci.2008.02.010.
23
llama
•
The llama (Llama glama) and the alpaca
(Vicugna
pacos) are domesticated whilst the other two species are still wild and only a few farms have started farming with these two.
•
The nutritional content of these two camelids
have been reviewed recently by Saadoun
and Cabrera
(2008). •
The alpaca is mainly farmed for its fibre
Saadoun, A. & Cabrera, M. C. (2008). A review of the nutritional content and technological parameters of indigenous sources of meat in South America. Meat Science, doi:10.1016/j.meatsci.2008.03.027.
24
Llama glama
•
Comparison between animals reared in Chile and Peru•
Peru animals lighter•
Genetics•
Nutrition•
Note differences in f/a between animals reared in Chile and Argentina•
Diets
•
Castration : •
Decreased cholesterol•
Increased the linolenic
fatty acid content of the muscle fat. •
These changes are seen as being desirable from a health standpoint.
•
On the negative side, castration increased the subcutaneous fat cover and total fat content of the longissimus
muscles
25
Rodents
•
There are altogether 5000 species of rodent in the world,
•
Many of them are prized items in the diet for local people.
•
Fiedler (1990) lists 71 rodent genera representing more than 89 species that are consumed by man.
•
Many have the advantage of large litters combined with short gestation periods and early sexual maturity –
making them ideal meat producers
26
Guinea pig (Cavia
porcellus)
•
Stable meat for the poorest people in the Andes for at least 3000 years
•
20
000 tons of meat (64 million edible carcasses) annually
•
Yet limited nutritional information (in Western literature)
Farm raised guinea pigs have a dressing percentage of 65% and the meat contains approximately 21% protein and 8% fat
27
The capybara (Hydrochoerus
hydrochaeris)
•
Domesticated in Brazil as early as A.D. 1565•
Licensed ranches in Venezuela harvest about 85
000 animal every year
•
This is the largest rodent in the world (weighing about 50kg)
28
The capybara (Hydrochoerus
hydrochaeris)
•
Vegetarian rodent•
All recipes call for the removal of fat, usually by boiling three times and throwing away the fat and water.
•
The traditional way of processing capybara meat (in Columbia and Venezuela) is to salt and dry it.
•
After skinning, all the meat is separated from the carcass in one piece, washed thoroughly and then covered in coarse salt.
•
This meat is then folded and after 12 h, hung out to dry on poles in the sun.
29
The capybara (Hydrochoerus
hydrochaeris)
•
The lipid content varied between the loin (1.8- 2.3%) and the ham (3.9-4.7%)
•
Cholesterol content was similar between the two cuts and varied from 45.7 mg to 52.1 mg/100g wet weight).
•
F/a differences between the various studies can be attributed to slaughter weight and age, and management conditions
•
Capybara oil lowers the serum total cholesterol and VLDL+IDL+LDL-cholesterol concentrations in the presence of excess cholesterol in the diets of rats (Fukushima et al., 1997)
30
The nutria or coypu (Myocastor
coypus)
•
Farmed commercially •
Large (adults weigh 5-9 kg) semi aquatic rodent native to South America •
Europe, Asia and North America
Saadoun, A. & Cabrera, M. C. (2008). A review of the nutritional content and technological parameters of indigenous sources of meat in South America. Meat Science, doi:10.1016/j.meatsci.2008.03.027.
31
Grasscutters
or cane rats (Thryonomys
swinderianus
and Thryonomys
gregorianus)
•
Widely-distributed and valuable animals in West and Central Africa
•
Past 15 yrs -
research on farming & domestication•
In West Africa, the number of grasscutters
hunted
per year is estimated to be 80 million, the equivalent of 300 000 metric tons of meat •
Carcass yield of 64% and 22% protein and 4% fat, this species is highly sought after in Africa
32
Ratites
•
Ostriches•
Emus
•
Rheas•
Greater rhea (Rhea Americana) •
Lesser rhea (Pterocnemia
pennata)
•
Cassoways•
Kiwis
33
Ratites
•
South Africa is regarded as a pioneer and world leader in the ostrich industry•
90% of the ostrich meat produced in South Africa is exported to the EU as chilled meat (-2 to -4°C)
34
Ratites
•
Export orientated ostrich industry suffered a setback•
Avian influenza banned export of ostrich meat•
Result was over supply of unprocessed ostrich meat in the South African market
•
Frozen, defrosted and processed further
35
Ostrich
•
Ostrich meat products that have undergone heat treatment to a core temperature of 70°C, is allowed by the EU commission to be imported.
•
The ostrich meat industry became compelled to conduct more scientific research on the development of heat-
treated ostrich meat products.
36
Ostriches
•
Various sub species and lines•
Long domesticated•
Feathers•
Skin•
Meat
Hoffman, L. C. (2008). Value adding and processing of ratite meat: A review. Australian Journal of Experimental Agriculture
37
Other Ratites
•
Emu•
Oil: retroperitoneal & subcutaneous adipose tissues•
Medicinal property Sales, 2007•
Creatine (N-[aminoiminomethyl]-N-methyl glycine)
Emu (mg/g DM) Beef (mg/g DM)
Meat 29.3 30.4
Jerky 22.8 21.7
Pegg
et al, 2006
38
Muscle yields
Component Ostrich Emu Rhea
Body weight (≈
kg) 85 41 25
Carcass weight (%) 59 53 61
Total lean meat (%) 39 34 36
Trimmings (%) 12 13 14
Little research on factors influencing yield/quality
39
Reptiles
•
Turtles are the most heavily exploited for human consumption
•
south east Asian medicinal trade•
Overexploitation of reptiles, especially turtles and snakes
Tegu
lizards (Tupinambis merianae)
40
Crocodiles (Crocodylus
niloticus)
•
Successful farming –
species conservation•
Zimbabwe, South Africa, Australia and other countries in Asia
•
Meat & skins•
total fatty acids present in the tail samples of crocodiles, •
37.7% were saturated, •
51.1% monounsaturated and •
10.7% polyunsaturated. •
Oleic acid was predominant (43.1%), whilst palmitic
acid (25.4%), stearic
acid (9.9%) and linoleic
acid (9.1%) were also present in high concentrations
41
Crocodiles (Crocodylus
niloticus)
•
Questions •
Parasites?Slaughter procedures –
shooting / capture / electrically stunning- microbiology?
42
Conclusion
•
Although the consumption of other alternative species is more common than anticipated, very little data is available on the nutritional value of their meat.
•
This is partly attributable to the fact that most of these species are consumed by poorer people who tend to hunt and consume them locally or market them on the informal (and often illegal) market.
•
It is only where the commercial production/farming of these species has started, that nutritional information is becoming available.
•
World globalisation -
people of different cultures are now readily found in most countries and their need for their own cultural food dishes will only increase resulting in the expansion of the legal (an illegal) trade in these alternative species and their meat.
•
Rodents seem to have great potential, •
remember that these animals can just as readily become pests and
cause great harm to commercial crops and the environment.
43
Thank you
