Lecturer Student THE OSTRICH AS MEAT ANIMAL - ANATOMICAL

85 Pages·2009·1.88 MB·English

THE OSTRICH AS MEAT ANIMAL
ANATOMICAL AND MUSCLE CHARACTERISTICS
Lecturer Prof. W.A. VOSLOO
Student F.D. MELLETT
ANIMAL SCIENCE (MEAT SCIENCE)
Thesis presented in partial fulfilment of the
requirements for the de0ree Master of Science
in Agriculture at the University of Stellenbosch
November 1985
ACKNOWLEDGEMENTS
I he~e~y wi~h to exp~e~~ my app~eciation to the management
and pe~~onnef ot the Kfein Ka~oo Land~ou Koope~a~ie in
Oudt~hoo~n to~ ~uppfying aff the mate~iaf needed to~ and
cove~ing aff expen~e~ ot thi~ ~tudy. I af~o wi~h to thank
p~ote~~o~ W.A. Vo~foo to~ hi~ ~uppo~t du~ing thi~ ~tudYI a~
weff a~ hi~ pe~~onaf inte~e~t in my academic ca~_~e~ du~ing
the pa~t ten yea~~.
Tinaffy I wi~h to thank my empfoye~1 Vfei~~ent~aaf, to~
g~anting me pe~mi~~ion to ca~~y out thi~ ~tudYI a~ weff
a~ the fa~o~ato~y pe~~onnef ot the Spekenam tacto~y to~
a~~i~ting me in the chemicaf anafy~i~ and ~en~o~y evafuation~.
Francois Mellett
INTRODUCTION
The domestication of ostriches and commercial ostrich breeding
has a long and interesting history. r;striches were success=
fully domesticated in Algeria during 1857 and also success=
fully bred in Italy during 1859. *In South Africa the domesti=
cation of wild ostriches started in the Cape Colony with 80
tame birds during 1865. This number increased to 32 247 birds
within ten years (De Mosenthal, 1877). Ostrich farming reached
a peak during 1913 with 757 000 birds (De Jager, 1985, personal
communication). Currently (1985) there are approximately
120 000 domesticated ostriches in South Africa.
I'
I The commercial production of ostrich meat started in 1958 and
!
Ie
the first abattoir was built in 1964. TAt the present moment
85 000 birds are slaughtered anually. Although the income
I I from the carcass of a 14 month old ostrich comprise only 15%
~'\
\ of the total income of a 14 month old bird (With the hide
\
\\compriSing 65% and, the first harvest feathers 20%), the sub=
jects of carcass characteristics and meat quality has long
been neglected. Very little is known about the anatomy of the
skeleton and muscles of the ostrich, the P06t mo~tem reactions
of these muscles and the effects of different slaughtering,
chilling and deboning practices. The necessity of the above
mentioned have proved very usefull in the beef, sheep, pork
and poultry industries.
*
With this present study we described the essential skeletal
and muscular anatomy and included well known practices to the
meat industry, such as electrical stimulation of the carcasses,
~P06t mo~tem pH monotoring of certain muscles, different debo=
'\ ning practices and vacuum packed ageing of selected cuts of
ostrich meat. The obtained results are in agreement with
general meat science, with expected inter-6pec~e6 variation,
e.g. where the final pH-values of pork is relatively low at
approximately 5,5; that of beef is higher at 5,7 and ostrich
meat even higher at 6,0.
Certain other fields of essential research are pointed out
in this study, such as the growth and development of the
ostrich, as well as certain basic biochemical research on the
meat of the ostrich.
I N D E X
Page
1 GENERAL 1
1.1 THE ZOOLOGICAL POSITION OF THE OSTRICH 1
1.2 / THE OSTRICH AS DOMESTICATED FARM ANIMAL 2
1.3 TERMONOLOGY 2
1.4 LIST OF ABBREVIATIONS USED IN TEXT AND FIGURES 3
2 SKELETON OF THE OSTRICH 4
2. 1 GENERAL CONSIDERATIONS 4
2. 2 SKELETON OF THE HEAD (o44a c~anii) 4
2.3 SKELETON OF THE TRUNK 10
2.3.1 GENERAL 10
2.3.2 VERTEBRAL COLUMN (co£umna v£~t£R~a£i4) 10
2.3.3 BREAST BONE (4t£~num) 18
2.3.4 RIBS (co4tad 18
2.4 SKELETON OF THE FORELIMB (m£mR~i tho~acici) 21
2.4.1 BONES OF THE PECTORAL GIRDLE (o44a cingu£i
m£mR~i tho~acici) 21
2.4.2 BONES OF THE WING (o44a a£a£) 21
2.5 SKELETON OF THE HINDLIMB (m£mR~i p££vini) 24
2. 5. 1 BONES OF THE PELVIC GIRDLE (o44a cingu£i
m,,-mR~i f'££vini) 24
2.5.2 BONES OF THE PELVIC LIMB (o44a m£mR~i
f',,-£vini) 27
3 MUSCLES OF THE PELVIC LIMB 31
3. 1 GENERAL CONSIDERATIONS 31
3.2 PRE-ACETABULAR REGION 32
3.2.1 ~. i£iotiRia£i4 c~ania£i4 32
3.2.2 ~. i£iot~ochani£~icu4 £xt£~nu4 34
3.2.3 ~. i£ioi~ochant£~icu4 int,,-~nu4 34
3.2.4 ~. i£ioi~ochani£~icu4 c~ania£i4 36
3.2.5 ~. i£iot~ochant£~icu4 m,,-diu4 36
3.2.6 ~. i£iot~ochant£~icu4 cauda£i4 36
3.2.6 (7. amRi£n4 38
3.2.8 (7. g~aci£i4 39
3.3 POST ACETABULAR REGION 39
3.3.1 (7. i£iotiRia£i4 £at£~a£i4 39
3.3.2 n.ilioti!ulani~ 41
3.3.3 A. tlexon cnuni~ latenali~
3.3.4 A. caudiliotemonali~ 43
3.3.5 A. tlexon cnuni~ mediali~ 43
3 .3 .6 A. puRi~chiotemonali~ 43
3.3.7 A. i~chiotemonali~ 44
n.
3.3.8 oRtunaton intennu~ 44
n.
3.3.9 oRtunaton extennu~ 45
3.4 MUSCLES OF THE THIGH 45
n.
3.4.1 temonotiRiali~ extennu~ 45
3.4.2 A. nectu~ temoni~ 45
n.
3.4.3 temonoti!iali~ mediu~ 47
3.4.4 A. temonotiRiali~ intennu~ 47
3.5 MUSCLES OF THE LOWER LEG 47
3.5.1 A. ga~tnocnemiu~ 47
3.5.2 A. penoneu~ longu~ 49
4 ~ COMMERCIAL CARCASS DIVISION AND MUSCLE
. MASS DISTRIBUTION 51
4. 1 THE OSTRICH IN COMPARISON TO OTHER MEAT
ANIMALS 51
4.2 COMMERCIAL CARCASS DIVISION 52
4.2.1 LEG 53
4.2.2 LOIN 54
4.2.3 NECK 54
4.2.4 WING 54
4.2.5 BREAST 54
4.2.6 TAIL 54
4.3 INDIVIDUAL MUSCLE MASS DISTRIBUTION 55
4.4 !PROTEIN AND FAT CONTENT OF OSTRICH MEAT 55
5 POS7 nOR7[A MUSCLE ACTIVITY 57
5. 1 GENERAL OBSERVATIONS 57
5.2 DETECTION OF POS7 ~OR7[n MUSCLE CONTRACTION 57
5.3 POS7 AOR7[n pH-PATTERN OF THE ILIOFIBULAR
AND FEMOROTIBIAL MUSCLES 59
6 PALATABILITY 62
6.1 PILOT TRIALS 62
6.1.1 GENERAL REMARKS 62
6.1.2 METHOD AND PROCEDURES 62
6.1. 3 RESULTS 64
6.1. 4 DISCUSSION 64
6.1. 5 CONCLUSION 67
I
6.2 TENDERIZING OSTRICH STEAK CUTS BY VACUUM
PACKED AGEING 68
6.3 / RECOMMENDATIONS TO IMPROVE TENDERNESS OF
OSTRICH STEAK MUSCLES 69
7 TECHNOLOGICAL ASPECTS 71
7. 1 ~MULSION PRODUCTS 71
7.2 fl1INCED PRODUCTS 71
7.3 ytMI-DRIED, SMOKED PRODUCTS 71
7.4 PRIED PRODUCTS 71
8 CONCLUSIONS 73
REFERENCES 74
1
1 GENERAL
1.1 THE ZOOLOGICAL POSITION OF THE OSTRICH
During the nineteenth and first half of the twentieth centuries
the class Aveh was subdivided into three orders, or sometimes
called subclasses, namely Sau~u~ae (lizard-tailed birds of which
only fossils exist), Ratitae (flat breastbone) and Ca~inatae
(modern birds with a keel on the breastbone). Such references
are De Mosenthal (1877), Stark (1900), and Bradley and Grahame
(1950). In this classification the ostrich was considered as
a member of the subclass Ratitae, order St~uthionehl family
St~uthionidae, genus St~uthio and further differentiated into
four species, namely S. aUht~af.ihl S. camef.uh, S. mahaicuh and
S. mof.yP..dol'haneh (Stark and Sclater, 1906). It has since been
established that there is only one species, namely S. camef.uh.
The current zoological classification of the ostrich is pre=
sented in Table 1.1. This classification is in agreement with
McLachlan and Liversidge (1978), Getty (1975) and Welty (1975).
Table 1.1 Zoological position of the ostrich
Class I1veh
Subclass Neo~nitheh
Superorder Neognathae
Order St~uthionito~meh
Family St~uthionidae
Genus St~uthio
Species came£Uh
In this classification system all living birds are members
of the subclass Neo~nitheh and superorder Neognathae, while
the fossil birds are classified in another subclass l1~chaeo=
mithehl although a few New World fossil birds are members of
the subclass Neo~nitheh and superorder Odontognathae (Welty,
1975). The ostrich and other flightless birds with a flat
sternum are not members of the same order.
2
X1.2 THE OSTRICH AS DOMESTICATED FARM ANIMAL
\ Although ostriches were hunted for their meat centuries ago
(De Mosenthal, 1877), the real motivation for the domestication
of the ostrich was the production of feathers during the second
half of the nineteenth century. Since then the demand for
feathers declined somewhat, but the leather articles made from
the treated hides are still very popular. De Mosenthal (1877)
referred to the use of ostrich meat and recognized the potential
of ostrich meat with remarks like "seeing the present prices
charged for beef and mutton, that ostrich-meat may one day form
an important item in our food supply "and "the meat is said to
be palatable, and in flavour not unlike young beef". He also
mentioned the "long and muscular neck" and the "extremely mus
cular thighs" which, today sell as products resembling oxtail
and beef steaks.
~ The optimal age of slaughtering ostriches for maximum utiliza
tion of the hides, feathers and feed conversion efficiency is
when the birds are fourteen months old (De Waal, 1984, personal
communication). At this age the animals are not fully matured
physiologically and the meat thus produced can indeed be very
succulent and palatable.
1.3 TERMONOLOGY
In order to carry out a study on the relative aspects of any
meat, the muscles must be anatomically identified, as men
tioned by Naude, Van Rensburg, Smit, Stiemie, Dreyer, Rossouw
and De Jager (1979). This present study deals with the anato
mical nomenclature and description of the skeleton and the
muscles of the hind limb, as well as the mass distribution of
these muscles and some commercial, retail and technological
aspects of the meat of the ostrich. The termonology applied is
the latest available terms in accordance with Nomina Anatomica
(1977), although this publication does not deal with the
ostrich.
1.4 LIST OF ABBREVIATIONS USED IN THE TEXT AND FIGURES
acc. = accesorius
art. = articulatio
caud. = caudalis
cm = centimeter
cran. = cranialis
crur. cruris
ext. = externus
fern. femoris
flex. flexor
for. foramen
fov. = fovea
g = gram
h = hour
into = internus
intm. intermedius
kg = kilogram
lat. = lateralis
m. = muscularis
med. medius
medi. = medialis
min. = rninimus
proc. = proximalis
s. = seu
ventr. = ventralis
In the plural form the last letter of the abbreviation is
duplicated.