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Carcass traits in relation to genotype in sheepCloete, Jasper J. E. (Jasper Johannes Erasmus) 04 1900 (has links)
Thesis (MScAgric) -- University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Experiment 1: Two studies were conducted to research the effect of divergent selection for
multiple rearing ability on carcass weight, mutton production, meat quality and carcass
characteristics of similar-aged Merino sheep. Data of 114 19-month-old Merino sheep, 40 ewes and
74 rams were used in this study. The study was done in two parts over 2 years. Only rams (52)
were slaughtered over a two-week period in study A. Twenty-two rams and 40 ewes were
slaughtered over a three-week period in study B. The sheep were descended from two selection
lines that have been divergently selected for maternal multiple rearing ability since 1986. In brief,
ewe and ram progeny of ewes rearing more than one lamb per joining (i.e. that reared twins at least
once) were preferred as replacements in the high (H) line. Descendants of ewes that reared fewer
than one lamb per joining (i.e. that were barren or lost all lambs born at least once) were preferred
as replacements in the low (L) line. In study A the mean (±SE) slaughter weight of H line rams
. were 12% heavier (P<O.OI) than that of L line contemporaries. A corresponding difference
(P<O.OI) of 13% was found for carcass weight Adjustment for the higher live weight by analysis
of covariance ofH line rams resulted in most of the line differences being eliminated (P>0.05). The
difference between the weight of the loin retail cut remained significant (P<O.OI) in favour of the H
line (1.64±0.04 vs. 1.37±0.08 kg, respectively). Skin weight (3.93±0.15 vs. 3.34±0.07 kg
respectively; P<O.OI) and skin thickness (2.28±0.1l vs. 1.97±0.06 mm respectively; P<0.05) were
greater in L line rams than in H line contemporaries. Rams in the L line also had heavier (P<0.05)
trotters than the H line (l.05±0.03 vs. 0.96±0.02 kg respectively). In study B there were no
interaction between line and sex and the data were pooled to present the main affects of sex and
line. In study B the mean (±SE) slaughter weight of H line animals was 7% heavier (P=0.05) than
that of L line contemporaries (44.02±0. 7 vs. 41.2±1.2 kg, respectively). A corresponding difference
(P<0.05) of 11% was found for carcass weight between the two lines (pooled sexes) (l6.1±0.3 vs.
14.4±0.5 kg, respectively). There was no difference in the tenderness of the meat between the two selection lines but L line animals tended (P<0.16) to have more tender meat than H line
contemporaries. Adjustment for the higher live weight of H line animals by analysis of covariance
resulted in most of the line differences being eliminated (P>0.05). Hindquarter weight still
remained significantly (P<O.OI) in favour of the H line after correction for live weight. Meat of L
line animals was healthier based on their PUF A/SF A ratio.
Experiment 2: This experiment was conducted to quantify the effect (noted in the first
experiment) of selection for and against multiple rearing ability in Merino sheep on m. longissimus
dorsi postmortem pH profiles. Data of 20 Merino sheep (10 rams and 10 ewes) were used. The
sheep were slaughtered at a commercial abattoir. After slaughter pH was measured at 45 min, 2, 4,
8, 10, 12, 16, 20, 24, 33 and 48 h post slaughter, respectively. The pH was measured on the right
side of each carcass in the m. longissimus dorsi between the 1st and the 6th lumbar vertebrae. The
m. longissimus dorsi between the 1st and the 6th lumbar vertebrae of the left side was used for meat
quality analysis. The initial pH of H line animals tended to be higher than that of L line
contemporaries. At 48 h post-slaughter the pH of L line was higher (P<0.05) compared to that of H
line animals. The meat of H line animals was tougher (99.79±3.58 vs. 88.32±3.38, P<0.05) than
that of L line contemporaries, but there were no differences in the other meat quality characteristics.
A higher initial pH (found in the first experiment, with a similar tendency in the second experiment)
could indicate a lower susceptibility to stress in the H line.
Experiment 3: An experiment was done to compare the meat-production potential between
Merino and South African Mutton Merino (SAMM) ewes with increasing age. Slaughter data of
. 653 Merino and SAMM ewes were used. Animals were slaughtered between 220 and 2719 days of
age, which encompassed a range of slaughter weights from 27 to 100 kg. The ewes were
differentiated according to age, 219 ewes being younger than 600 days and 416 being older than
600 days at slaughter. Young SAMM ewes had 10% heavier carcass weights than young Merino
ewes and the difference was 47% between mature ewes. Mean maximum carcass weights of 33.44
and 22.65 kg were derived for the SAMM and Merino, at respective age of 2100 and 1900 days.
SAMM ewes had a 47% thicker fat depth. Although Merinos were earlier maturing than the
SAMM ewes, the latter breed had more subcutaneous fat at the mature stage.
Experiment 4: The fourth experiment examined the effect of breed and sex on the carcass
composition, yield of retail cuts, fat depth and chemical composition of meat from 35 South African
Mutton Merino (SAMM) (17 rams and 18 ewes) and 61 Dormer (21 rams and 40 ewes) sheep. As
there was no breed x sex interaction, the data were pooled to present the main effects of breed and
sex. There were no differences in slaughter and carcass weight between Dormer and SAMM sheep.
Dormers' had more fat (kidney, back fat depth) than SAMM sheep. The eye-muscle area of the Dormers' was 13% larger than that of the SAMM sheep. Rams were heavier (64.86±0.85 vs.
44.55±0.74 kg) than the ewes at slaughter. All the traits that were recorded, were heavier or higher
in rams (P<0.05). After adjustment for higher live weight of the rams, the proportion of neck retail
cut from the rams was higher than that from ewes and the proportion of hindquarter weight from the
ewes was higher (P<0.05) than that from rams. After adjustment for the higher live weight of the
rams, the moisture (75.35±0.37 and 73.35±0.37%) and lipid (2.68±0.33 and 3.80±0.33%) contents
differed significantly (P<0.05) between the rams and ewes, respectively. With the significantly
higher SFA value of the SAMM sheep and higher MUF A value of the Dormer sheep, meat from
Dormer sheep could be regarded as healthier from a human prospective than that from SAMM
sheep.
Experiment 5: A study was done to test an ultrasound scanner (used on pigs) for the
prediction of subcutaneous backfat and m. longissimus dorsi depth on Merino (52 rams), SA
Mutton Merino (17 rams and 18 ewes) and Dormer (21 rams and 40 ewes) sheep. The sheep were
scanned with an ultrasound scanner to predict the backfat and eye-muscle depth on the live animal.
All animals were slaughtered to measure the true values of the fat depth and eye-muscle depth (25
and 45mm from the midline at the 13th rib). Overall regression equations over breeds (SAMM and
Dormer, pooled breeds), and lines (H and L line Merinos, pooled lines) were obtained. Compared
to previous research, the correlations between scanned values and true values were comparatively
low (r = 0.07 - 0.25). Evidence from the literature suggested higher correlations of r = 0.53 - 0.56.
Higher correlations could be achieved in older and fatter animals. The fact that the operator had no
experience of scanning sheep could also have contributed to the low correlations. / AFRIKAANSE OPSOMMING: Eksperiment 1: Twee studies is gedoen om te kyk na die invloed van seleksie vir meerling
grootmaakvermoe by Merino's op karkas-, vleiseienskappe en vleiskwaliteit is. Data van 114 19
maand oue Merino skaap, 40 ooie en 74 ramme is in die studie gebruik. Die studie is gedoen in
twee dele oar 'n tydperk van twee jaar. Slegs ramme (52) is geslag oor 'n tydperk van twee weke in
studie A. Twee en twintig ramme en 40 ooie is in studie B geslag oor 'n pericde van drie weke.
Merino-ooie en -ramme afkomstig van 'n hoe (Il-lyn) en lae (L-lyn) lyn geselekteer vir rneerling
grootmaakverrnoe is gebruik in 'n studie wat oor twee jaar uitgevoer is. Die twee lyne is intensief
geselekteer vir en teen meerling grootmaakverrnoe vanaf 1986. Ram- en ooi-nageslag wat
afkomstig is van ooie wat een of meer keer tweelinge in haar lewe per lam kans groot gemaak het is
gebruik vir die H-lyn, terwyl ram en ooi nageslag afkomstig van ooie wat een of minder as een lam
per lamkans groot gemaak het is gebruik vir die L-Iyn. In studie A is 52 rarnme (42 H-Iyn en 10 Llyn)
geslag en slag- en karkaseienskappe is bestudeer. In ondersoek B is 22 ramme (16 l-l-lyn en 6
L-lyn) en 40 coie (34 H-Iyn en 7 L-Iyn) gebruik. Slag-, karkas- en vleiseienskappe is bestudeer. In
ondersoek A is gevind dat die slagmassa van die Il-Iyn ramme 12% hcer en die karkasmassa 13%
hcer is as die van die L-lyn ramme. Na kovariansie ontleding van die swaarder slagmassa van die
H-Iyn diere, was die pote (1.05±0.03 vs. 0.96±0.02 kg; P<0.05) en velie swazrder (3.93±0.15 vs.
3.34±0.07 kg; P<O.Ol) en die velle dikker (2.28±0.11 vs. 1.97±0.06 mm; P<0.05) by L-Iyn diere as
by H-lyn diere. Die groothandel lende snit van die H-Iyn diere was swaarder (1.64±0.04 vs.
1.37±0.08 kg; P<0.05) as die van L-Iyn diere. By studie B was daar geen interaksie tussen lyn en
geslag nie, dus is die data verpoel om die betekenisvolheid van die hoofeffekte van lyn en geslag
weer te gee. 'n Sewe persent hoer slagmassa is by H-Iyn diere waargeneem (44.02±0.7 vs.
41.20± 1.2 kg; P<0.05). 'n Ooreenstemmende verskil van (P<0.05) 11% is gevind in karkas massa
tussen die twee lyne (16.1±0.3 vs. 14.4±0.5 kg). Daar was geen veskil in taaiheid van die vleis nie,
maar diere van die H lyn se vleis het geneig (P<0.06) om taaier te wees. Na die kovariansie ontleding met massa as kovariant was die boude (P<O.OI) van die H-lyn diere en die lende (P<O.OI)
groothandel snit van die ooie swaarder, verder was die verskille dieselfde as in ondersoek A Die
vetsuurresultate toon dat net by die verhouding tussen die poli-onversadigde en vesadigde vetsure
(PUF A/SF A) 'n verskil tussen die Iyne was. Die vetsuur resultate dui daarop dat die Llyn diere
gesonder vleis vir menslike voeding het as die van die H Iyn diere.
Eksperiment 2: In 'n tweede eksperiment is gekyk wat die invloed van seleksie vir meerling
grootmaakvermoe by Merino skape op post mortem m. longissimus dorsi pH profiele is. Daar is
gebruik gemaak van 20 Merino skape (10 ooie en 10 ramme), 10 H lyn en 10 Llyn diere. Die
skape is geslag by 'n kornrnersiele abattoir. Die pH metings is geneem, 45 min, 2, 4, 6, 8, 10. 12,
16, 20, 24, 33 en 48 uur na slag. Die pH is geneem in die m. longissimus dorsi van die regter sy
tussen die 1ste en 6de lumblale werwels. Die linker kant is gebruik vir vleiskwaliteits toetse Die pH
lesing van H lyn diere wat 45 min na slagting geneem is het hoer geneig as in Llyn, terwyl pH
lesings van die Llyn diere 48 h na slagting hoer was. Die vleis van die H lyn diere was taaier
(99.79±3.58 vs. 88.32±3.38; P<0.05) as die van die Llyn diere, maar daar was geen verskille in die
ander vleiskwaliteits toetse nie. Die hoe begin pH kan daarop dui dat die H lyn skape minder
spanning voor slag ervaar he!
Eksperiment 3: Die invloed van ouderdom op vleis produksie potensiaal, slag en
karkasmassa en vetdikte by Suid Afrikaanse Vleis Merino (SAVM) en Merino ooie is ondersoek.
Data van 635 Merino en SAVM ooie is gebruik. Die ooie was tussen 220 en 2719 dae oud met
slagting en slagmassas wat gewissel het tussen 27 en 100 kg. Die ooie is opgedeel ten opsigte van
ouderdorn. Die jong groep was ooie wat jonger as 600 dae oud was en die die res was bestempel as
die ou groep. Die karkas massa van die jong SAVM ooie was 10% hcer as die van die Merino ooie
en by die ou groep was die verskil 47% Ouer SAVM ooie het 52% dikker vet as die Merino ooie
gehad. Merino ooie het 'n maksimum karkas massa van 22.65 kg op 'n ouderdom van 1900 dae
gehad terwyl SAVM ooie 'n maksimum karkas massa van 33.44 kg op 'n ouderdom van 2100 dae
gehad he! Al is die Merino 'n vroer ryp skaap as die SAVM, het die SAVM meer vet as volwasse
dier.
Eksperiment 4: In die experiment is gekyk na die effek van ras en geslag op slagmassa,
karkasmassa, vleiseienskappe asook chemiese en vetsuur samestelling van die vleis van SAVM en
Dormer skape. Slagdata van 61 Dormers' (21 ramme en 40 ooie) en 35 SAVM's (17 ramme en 18
ooie) is gebruik, Daar was geen interaksie tussen ras en geslag nie en dus is die data verpoel om die
invloed van die hoof effekte (ras en geslag) te toets. Geen verskille is in die slagmassa tussen die
Dormers en SAVM gevind nie. Die vet (onderhuids en niervet) van die Dormers was meer en die
oogspier oppervlakte was 13% groter as die van SAVM skape. Ramme was swaarder (64.86±0.85 vs. 44.55±0.74 kg) as die ooie met slag. Na kovariansie ontleding van swaarder slagmassa van die
ramme was die groothandel nek snit van die ramme swaarder (P<0.05) as die van die ooie en die
boude van die ooie swaarder (P<O.Ol) in vergelyking met die van die ramme. Die voginhoud van
vleis vanaf ramme was hoer (77.35±0.37 vs 75.35±0.37) as die van die coie. Ooie het 'n hcer
persentasie vet in die vleis van die 11113de ribsnit gehad (2.68±0.33 vs. 3.80±0.33 %) Volgens die
vetsuur analises het SAVM diere 'n hoer persentasie versadigde vetsure en die Dormers 'n groter
persentasie mono-onversadigde vetsure gehad. Dit kan 'n aanduiding wees dat vleis vanaf Dormer
skape gesonder is vir menslike gebruik.
Eksperiment 5: Hierdie studie is gedoen om 'n ultraklank apparaat (gebruik by varke) te
toets vir voorspelling van onderhuidse vet en oogspierdiepte by skape. Daar is gebruik gemaak van
52 Merino ramme (42 van die H-lyn en 10 van die Llyn), 61 Dormer skape (21 ramme en 40 ooie)
en 35 SAVM skape (17 ramme en 18 ooie). Die vetdikte en oogspierdiepte op die lewende diere is
bepaal met 'n ultraklank apparaat, waarna die diere geslag is en die werklike waardes direk op die
koue karkas gemeet is. Regressie vergelykings is opgestel om korrelasies tussen ultraklank waardes
en werklike waardes te kry. In hierdie proef was die korrelasies tussen geskatte en werklike
waardes swak (r = 0.07-0.25). Beter korrelasies is egter weI deur ander navorsers gekry (r = 0.53-
0.56) Beter korrelasies kan in ouer en vetter diere verkry word. Die feit dat die operateur nie baie
ondervinding met die skandering van skape gehad het nie kon bydrae tot die swak korrelasies.
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Meat quality characteristics of three South African game species : black wildebeest (Connochaetes gnou), blue wildebeest (Connochaetes taurinus) and mountain reedbuck (Redunca fulvorufula)Van Schalkwyk, Sunet 03 1900 (has links)
Thesis (MSc Consumer Science)--Stellenbosch University, 2004. / ENGLISH ABSTRACT:
Please see fulltext for abstract / AFRIKAANSE OPSOMMING:
Sien asb volteks vir opsomming
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Ralgro implanted bulls : performance, carcass characteristics, longissimus palatability and carcass electrical stimulationGreathouse, John Ralph January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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Meat quality parameters of the impala (Aepyceros melampus)Kritzinger, Brian 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The purpose of this study was to evaluate the effects of age, sex, region and cropping
methodology on the meat quality of impala. Forty impala were cropped during separate
day and night operations at the Mara Agricultural Development Centre. Carcass pH45
(measured in M. longissimus dorsi 45 minutes post mortem) was higher in night cropped
animals (6.67 ± 0.111; P<0.05) compared to the day cropped animals (6.55 ± 0.236).
The ultimate carcass pH (pHu) of animals cropped at night was lower (5.39 ± 0.081;
P<0.05) compared to those cropped in the day (5.45 ± 0.108). Non-linear regression
analysis showed that the rate of pH decline of the night cropped animals was slower
than that of the day cropped animals (P<0.05). The cooling rate of the M. longissimus
dorsi was twice as fast in the night cropped group (P<0.05). Shear force values and drip
losses of the night cropped animals were both lower (19.11 ± 5.675 g/mm2 and 2.93 ±
1.597% respectively; PO.OS) compared to those of day cropped animals (23.42 ± 8.128
g/mm2 and 4.15 ± 2.339%). The results indicate that nighttime cropping has a beneficial
effect on certain meat quality parameters compared to daytime cropping.
A second group of impala was sampled at the Musina Experimental Farm in the
Limpopo Province of South Africa. Live weights of the Mara animals (50.23 ± 9.32 kg)
were higher (P<0.05) than the Musina animals (44.25 ± 10.81 kg). Impala sampled at
Mara had significantly higher dressing percentages than those at Musina (P<0.05).
Impala ewes from both regions had a higher lipid content (P<0.05), but the sex of the
animal had no effect on the remaining chemical parameters. The crude protein content
of impala at Musina (24.88 ± 1.044%) was higher (P<0.05) than the Mara animals (23.80
± 0.840%).
Regional differences (P<0.05) were found in the amounts of phosphorous and calcium in
the meat. Female animals at Mara showed higher proportions (P<0.05) of saturated
(SFA), and mono-unsaturated fatty acids than the male animals. Males from both
regions showed higher proportions (P<0.05) of poly-unsaturated fatty acids. Myristic,
palmitic and stearic acid formed the greatest proportion of the SFA component for males
and females from both regions. Samples of the M. semi-membranosus (SM), M. deltoideus (D), M. longissimus dorsi et
laborum (LO), and M. psoas major (PS) were analysed for citrate synthase (CS) and
phosphofructo-kinase activities. MHC distribution varied significantly between 0, SM and
LD (P<O.05). D expressed more MHC I, and less MHC lIa than the other three muscle
groups. Positive correlations were found between age and MHC I in 0 (r=O.93; P<O.05)
and CS and weight of the animal in D (r=O.76; P<O.05). The enzyme activities and MHC
distribution indicate that energy in the impala is produced to a large extent via oxidative
pathways. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die invloed van ouderdom, geslag, area, en
uitdunmetodes op die vleiskwalitiet van rooibokke te evalueer. Veertig rooibokke is
gedurende afsonderlike dag en nag uitdunningsoperasies by die Mara Landboukundige
Ontwikkelings Sentrum geoes. Karkas pH45 (gemeet in die M. longissimus dorsi 45
minute post mortem) was hoër (P<0.05) in nag-geoesde diere (6.67 ± 0.11) in
vergelyking met die dag-geoesde diere (6.55 ± 0.23). Die finale pH (pHu) van diere wat
in die nag geoes is (5.39 ± 0.08) was laer (P<0.05) in vergelyking met die wat in die dag
geoes is (5.45 ± 0.11). Nie-lineêre regressie analise toon dat die tempo van pH-daling
van die nag-geoesde diere merkbaar stadiger was as die dag-geoesde diere (P<0.05).
Die afkoelings tempo van die M. longissimus dorsi et lumborum was twee keer vinniger
in die nag geoesde groep (P<0.05). Die gemiddelde skeurkragwaarde en drupverlies
was beide laer (P<0.05) vir nag geoesde diere (respektiewelik 19.11 ± 5.67 g/mm2 en
2.93 ± 1.59%) in vergelyking met diere wat in die dag geoes is (23.42 ± 8.12 g/mm2 en
4.15 ± 2.33%). Die resultate toon dat nag-uitdunning 'n voordelige effek op vleiskwaliteit
gehad het, in vergelyking met dag-uitdunning.
'n Tweede groep van rooibokke is gemonster by die Musina Eksperimentele plaas in die
Limpopo Provinsie in Suid-Afrika. Die gewigte van die Mara diere (50.23 ± 9.32 kg) was
hoër (P<0.05) as die van die Musina diere (44.25 ± 10.81 kg). Die Mara groep het hoër
uitslag persentasies (P<0.05) gehad. Vroulike diere in beide areas het 'n hoër vet
inhoud (P>O.05) gehad. Die ru-proteien inhoud van die Musina diere (24.88 ± 1.04%)
was hoër (P<0.05) as die van die Mara diere (23.80 ± 0.84%).
Area verskille (P<0.05) is gevind in die fosfaat en kalsium inhoud in die vleis. Vroulike
diere by Mara het 'n hoër proporsie (P<0.05) van versadigde en mono-onversadige
vetsure in die weefsel as manlike diere gehad. Manlike diere van beide areas het 'n hoër
proporsie (P<0.05) van poli-onversadige vetsure (P<0.05) as die vroulike diere getoon.
Miristien, palmitien en stearien suur was kwantitatief die belangrikste vetsure in manlike
en vroulike diere van beide areas. Monsters van die M. semi-membranosus (SM), M. deltoideus (D), M. longissimus dorsi
et laborum (LO), en M. psoas major (PS), van die rooibokkarkasse is ontleed vir
sitraatsintase (SS) en fosfofruktokinase aktiwiteite (FFK). MSK verspreiding het
merkbaar varieer tussen 0, SM en LO (P<O.05). 0 toon meer MSK I en minder MSKlia
as die ander drie spiergroepe (P<O.05). Postiewe korrelasies is bevind tussen
ouderdom en MSK I in 0 (r=O.93; P<O.05), asook tussen SS en die gewig van die dier in
o (r=O.76; P<O.05). Die ensiemaktiwiteite en MSK verspreiding toon dat energie in die
rooibok tot 'n groot mate deur die oksidatiewe paaie geproduseer word.
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Effects of increased slaughter weight of pigs on pork productionPieterse, Elsje 04 1900 (has links)
Thesis (PhDAgric)--Stellenbosch University, 2006. / ENGLISH ABSTRACT: The South African pork industry is characterised by low slaughter weights
when compared to the rest of the world. This inevitably leads to a smaller
number of kilograms produced per unit fixed cost and subsequently the
efficiency of production is reduced. A study was conducted with 189 pigs
representing three sex types (boar, gilt and castrate) and five commercial
genotypes. Pigs entered into the trial at an age of 10 weeks and an average
live weight of 27.5±2.5kg. Treatments were according to slaughter weight
ranging between 62 and 146kg. Production and carcass characteristics, meat
quality and processing characteristics and sensory attributes were assessed.
Production characteristics assessed included live weight gains, intake, P2
backfat thickness and feed conversion ratio. Main observed effects were
associated with slaughter weight and its interaction with sex type. Rates of
change in parameters measured were described. Growth and feed
conversion ratio were described using linear models while cumulative feed
intake was described using 2nd order polynomials. Carcass characteristics
assessed included carcass weight, dressing percentage, carcass length, ham
length, ham circumference, chest depth, backfat thickness measurements,
muscle depth, eye muscle area, subcutaneous fat area, intramuscular fat area
as well as ratios of eye muscle to subcutaneous and intramuscular fat area.
The main statistical differences observed were for slaughter weight.
Significant sex type differences were observed for dressing percentage and
some fat and muscle depth measurements. Meat quality characteristics
assessed included colour measurements, tenderness, drip loss and water
holding capacity. Main differences observed were for slaughter weight.
Carcass yields were assessed in terms of absolute and percentage yields of
commercial cuts as well as yield of processable lean meat. In terms of the
absolute and percentage yields of the commercial cuts, the main statistical
differences observed were for slaughter weight. Changes in cut yield with increased slaughter weight are described using regression analysis. In terms
of yields obtained for processable lean meat, the main statistical differences
observed were for slaughter weight.
Sex type differences were only observed for percentage belly and topside
processable lean meat and percentage brine uptake of belly bacon, whole
gammon ham and topside gammon. Genotypic differences were observed for
percentage yield of processable lean meat of the neck and whole gammon
and percentage fresh to smoke losses of back bacon and whole gammon
ham. Sensory attributes were assessed using gammon ham, belly bacon and
fresh loin. Observed slaughter weight differences were inconsistent and did
not appear to change with an increase in slaughter weight. Once meat was
processed, most sensory differences were no longer observed. Increased
slaughter weight generally led to increased juiciness and decreased
tenderness.
It is therefore concluded that the current South African pig genotypes have the
ability to maintain high growth rates for a much longer time and therefore can
be slaughtered at a higher weight without detrimental effect on production
efficiency, carcass and meat quality characteristics, yields of commercial and
processable lean meat, processing characteristics and ultimately sensory
characteristics of the meat produced. / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse varkbedryf word gekenmerk deur relatiewe lae
slagmassas in vergelyking met die res van die wêreld. Dit lei onvermydelik tot
‘n kleiner aantal kilogramme vleis geproduseer per eenheid vaste koste. ’n
Studie is gevolglik gedoen met die doel om die tempo’s van verandering van
sekere produksie-, karkas-, vleis- en proseseringseienskappe te kwantifiseer
ten einde die optimale slagmassa te bepaal wat vir alle rolspelers in die bedryf
tot voordeel sal wees. Die studie is gedoen met 189 diere wat vyf
kommersiële genotipes en drie geslagstipes (beer, sog en kastraat)
verteenwoordig het. Varke is op ’n ouderdom van 10 weke met ’n gemiddelde
lewende massa van 27.5±2.5kg in die proef opgeneem. Behandelings was
volgens slagmassa en het gevariëer van 62 tot 146kg. Produksieparameters
en karkas-, vleiskwaliteits-, en proseseringseienskappe sowel as sensoriese
eienskappe, is ëvalueer.
Produksieeienskappe wat ëvalueer is sluit in: groei, inname, P2 rugvetdikte en
voeromset-verhoudings. Hoofeffekte wat waargeneem is, was vir slagmassa
en interaksies van slagmassa met geslag. Tempo van verandering in die
parameters gemeet, is beskryf. Groei en voeromsette is beskryf deur die
passing van ‘n linieêre model terwyl kumulatiewe voerinname beskryf is deur
‘n 2de orde polinoom. Karkaseienskappe wat ëvalueer is, sluit in:
karkasmassa, uitslagpersentasie, karkaslengte, hamlengte, hamomtrek,
borsdiepte, rugvetdikte, spierdiepte, oogspieroppervlak, onderhuidse vet-,
binnespierse vetoppervlak en verhoudings van oogspier- tot-vetoppervlakke.
Die hoof statistiese effekte wat waargeneem is, was vir slagmassa.
Betekenisvolle geslagsverskille is waargeneem vir uitslagpersentasie en
sommige, vet- en spierdieptemetings. Genotipiese verskille is waargeneem
vir sommige vetmetings. Vleiskwaliteiteienskappe wat beoordeel is, het kleur,
drupverlies, waterbindingsvermoë en sagtheid ingesluit. Hoofeffekte
waargeneem was vir slagmassa. Karkasopbrengste is ëvalueer in terme van absolute en persentasie opbrengste van kommersiële snitte sowel as
prosesseerbare maer vleis. In terme van absolute en persentasie opbrengste
van kommersiële snitte, was meeste van die variasie beskryf deur slagmassa.
Tempo van verandering in die persentasie opbrengste van die snitte word
beskryf. In terme van opbrengste vir proseseerbare maer vleis is die hoof
statistiese verskille waargeneem vir slagmassa. Geslagverskille is
waargeneem vir persentasie streepspek en binneboud maer vleis opbrengs
vir prosesering en persentasie pekelopname van streepspek, heel varkboud
ham en binneboud ham. Genotipe verskille is waargeneem vir persentasie
opbrengs van maer vleis vir prosesering van die nek en heelboud en
persentasie vars-tot-klaar-gerook verliese van rugspek en heelboud hamme.
Sensoriese eienskappe is ëvalueer vir twee geprosesseerde en een vars snit.
Slagmassa-effekte was nie konstant nie en parameters het klaarblyklik nie
verander soos slagmassa verander het nie. Sodra vleis geprosesseer is, het
die meeste sensoriese verskille verdwyn. Beide sappigheid en taaiheid het
toegeneem met ‘n toename in slagmassa.
Dit kan dus aanvaar word dat, gegewe die huidige Suid Afrikaanse genotipes,
dit moontlik is om swaarder karkasse te produseer sonder noemenswaardige
nadelige effekte op karkas-, vleis-, opbrengste-, prosesering- en sensoriese
eienskappe van varkvleis.
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Kinetic properties and characterization of purified proteases from Pacific whiting (Merluccius productus)Wu, JuWen 10 March 1994 (has links)
Kinetic properties of the two proteases, causing textural degradation of Pacific
whiting (Merluccius productus) during heating, were compared and characterized with the
synthetic substrate, Z-Phe-Arg-NMec. Pacific whiting P-I and P-II showed the highest
specificity on Z-Phe-Arg-NMec, specific substrate for cathepsin L. The K [subscript m] of
preactivated P-I and P-II were 62.98 and 76.02 (μM), and k [subscript cat], 2.38 and 1.34 (s⁻¹)
against Z-Phe-Arg-NMec at pH 7.0 and 30°C, respectively. Optimum pH stability for
preactivated P-I and P-II is between 4.5 and 5.5. Both enzymes showed similar pH-induced
preactivation profiles at 30°C. The maximal activity for both enzymes was
obtained by preactivating the enzyme at a range of pH 5.5 to 7.5. The highest activation
rate for both enzymes was determined at pH 7.5. At pH 5.5, the rate to reach the
maximal activity was the slowest, but the activity was stable up to 1 hr. P-I and P-II shared similar temperature profiles at pH 5.5 and pH 7.0 studied. Optimum temperatures
at pH 5.5 and 7.0 for both proteases on the same substrate were 55°C. Significant
thermal inactivation for both enzymes was shown at 75°C. Preactivated P-I and P-II
displayed a similar first order thermal inactivation profile at pH 7.0. At 30 and 90°C, half
lives, t [subscript 1/2], for Pacific whiting P-I were 49.50 and 0.20 min and for P-II, 32.54 and 0.18
min, respectively. The rate constant of inactivation for both proteases increased about
200-fold between two limits, 30 and 90°C. Half lives at 55°C, optimum temperature, for
P-I and P-II were also determined to be 5.29 and 6.75 min. The increase in thermal
inactivation rate constants independent of substrates corresponded to an activation energy
for heat denaturation of 21.18 kcal/mol for P-I and 19.97 kcal/mol for P-II by Arrhenius
plot. These similar kinetic properties, i.e., kinetic parameters, pH profile and thermal
inactivation rate constant, suggested that Pacific whiting P-I and P-II are the same
enzyme. / Graduation date: 1994
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THE INFLUENCE OF FRAME SIZE AND DAYS ON FEED ON CARCASS TRAITS AND COMPOSITION OF STEERS.Baco, Abdul-Aziz Ishak. January 1982 (has links)
No description available.
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Évaluation de l'efficacité de la pasteurisation à la vapeur pour le contrôle de la contamination microbiologique des carcasses bovinesCorantin, Harold January 2003 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Ambiente controlado e não controlado no desempenho, comportamento e características de carcaça de suínos /Berton, Mariana Piatto. January 2013 (has links)
Orientador: Hirasilva Borba / Banca: Maria Regina Barbieri de Carvalho / Banca: Caio Abércio da Silva / Resumo: A carne suína é a mais consumida em todo o mundo e o Brasil é o quarto produtor mundial desse produto. Este trabalho teve como objetivo avaliar a influência do ambiente controlado e não controlado em instalações de criação de suínos nas fases de crescimento e terminação no comportamento e parâmetros fisiológicos, bem como no desempenho e rendimento de carcaça dos suínos. Foram utilizados 20 suínos machos, castrados, da linhagem Topigs. Os tratamentos avaliados foram: Tratamento 1 (T1): ambiente controlado, mantido com temperatura constante (22°C) e com umidade relativa mantida em 70%; Tratamento 2 (T2): ambiente não controlado, o qual os animais permaneceram sujeitos às mudanças climáticas do ambiente. Os animais mantidos em ambiente não controlado na fase de crescimento apresentaram valores mais elevados (p<0,05) para temperatura da nuca e de pernil (34,99 e 34,26°C, respectivamente), enquanto que, na fase de terminação apresentaram maior (P<0,05) temperatura retal (39,44°C). Os animais de ambos os tratamentos, mantiveram- se deitados na maior parte do período. A criação de suínos em ambiente não controlado, obteve menor consumo diário de ração e menor conversão alimentar, porém não influenciou o rendimento de carcaça dos animais. Conclui-se que o uso de lâmina d‗água em baias de crescimento e terminação auxiliam na adaptação dos animais expostos as altas temperaturas, e a manter as atividades fisiológicas dentro de parâmetros normais, além de não influenciar nas características de carcaça / Abstract: The swine meat is the most consumed in the world and Brazil is the fourth largest producer of this product. The aim if this study was evaluate the influence of environment controlled and uncontrolled in growing and finishing in behavior and physiological parameters as well as the performance and carcass yield of pork. We used 20 barrows, the lineage Topigs. The treatments were: Treatment 1 (T1): controlled environment, maintained at constant temperature (22 ° C) and relative humidity maintained at 70%; Treatment 2 (T2): uncontrolled environment, which animals remained subject to changes ambient weather. Animals kept in uncontrolled environment in the growth phase showed higher values (p <0.05) for temperature neck and shank (34.99 and 34.26 ° C, respectively), whereas in the finishing phase had higher (P <0.05) rectal temperature (39.44 ° C). The animals from both treatments were kept lying in most of the period. Swine production in uncontrolled environment, had lower feed intake and feed conversion and did not affect carcass yield of animals. We conclude that the use of shallow pool in the growing and finishing bays helps in the adaptation of animals exposed to high temperatures, maintain physiological activities within normal parameters and does not influence carcass characteristics / Mestre
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Physical and chemical carcass characteristics as influenced by concentrate level, breed type and fat thickness endpointOchoa, Mario F. January 1981 (has links)
No description available.
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