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Phenotypic and genetic parameters for the S.A. strongwool merino strain with an emphasis on skin characters as early indicators of wool productivity / by Jane Adair Hill.Hill, Jane Adair January 2001 (has links)
Includes bibliographical references (leaves 325-341). / xxvii, 341 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Skin and fleece measurements were recorded at different ages for both male and female sheep from the Turretfield Merino Resource Flock and used to estimate the heritability of each trait and the phenotypic and genetic correlations among and between the skin and fleece traits. Generally, the heritability of each trait was high, which indicates that both the fleece and skin traits should respond well to selection. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2001
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An evaluation of degradable protein and nonprotein nitrogen on intake and digestion by Dohne merino sheep fed wheat strawNolte, Joubert van Eeden 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: South Africa, like many other developing countries throughout the world, has a rapidly
growing human population, resulting in a consequent increased demand for food. Ironically,
this increased food supply has to be produced on a smaller area of available agricultural land,
which means that agricultural production processes have to become more efficient.
Furthermore, the majority of the people in these countries are unschooled and poverty is a
common phenomenon. Therefore, animal scientists are faced with the challenge and the
responsibility to provide affordable, high quality food to these people.
One way of reaching this objective is to improve the utilisation of low-quality, high roughage
feedstuffs like crop residues and dry natural grass pastures. In the winter rainfall area of
South Africa alone, about 460 000 ha of wheat straw are annually available. The ruminant
animal has the ability to utilise the relatively unavailable energy (cellulose, hemi-cellulose
and pectin) in the fibre component of these low-quality forages. Unfortunately, various
factors, of which a N deficiency is the pre-dominant one, limit the utilisation of these
feedstuffs. If the ability of the ruminant to utilise low-quality, fibrous energy sources is
improved, these abundantly available and relatively inexpensive crop residues and natural
pastures can be converted into high quality protein food for human consumption. Therefore, in order to rectify the N deficiency caused by these low-quality forages, the
supplemental N requirement to optimise the fermentation and digestive processes of the
ruminant animal has to be determined. The first study was conducted to determine the
supplemental rumen degradable protein (RDP) requirement, to maximise the digestible
organic matter intake (DOMI) of Dohne Merino sheep fed wheat straw. Keeping the high
cost of natural protein supplementation in mind, the purpose of the second study was to
determine the amount of true protein that can be replaced by nonprotein nitrogen (NPN) in
RDP supplements fed to Dohne Merino sheep consuming wheat straw.
In both trials animals had ad libitum access to low-quality wheat straw (3.2% CP;
74.2% NDF) and water. In the first trial, RDP (calsium caseinate: 90% CP; 100% rumen
degradable) was intraruminally administered at 07hOOand 19hOO,at the following levels: 0,
40,80, 120 and 160 gld. Intake, fermentation and digestion were monitored to determine the
RDP requirement to maximise DOM!. Digestible organic matter (OM) intake displayed a
quadratic increase with elevated amounts of RDP (P < .01), and was maximised at an
estimated 3.15 g RDPlkg BW·75 or 11.6% of DOM. Forage OM intake tended to increase
quadratically (P = .15) with higher RDP levels. Microbial nitrogen (MN) flow to the
duodenum and microbial efficiency increased quadratically (P ~ .04) and fluid dilution rate
tended to increase in a quadratic manner (P = .15) with increased RDP supplementation
levels. Rumina! ammonia nitrogen (NH3-N) and total volatile fatty acid (VFA)
concentrations increased linearly (P ~ .07), while rumen pH exhibited a variable response to
increased RDP levels (cubic; P = .08). Increasing RDP supplementation to Dohne Merino
wethers consuming wheat straw, generally enhanced forage utilisation and DOM!.
In the second trial, urea replaced different levels of casein N on an isonitrogenous basis,
ranging from 0 - 100%. Since true protein is much more expensive than urea, the purpose of
this study was to determine the maximum natural protein level that can be replaced by urea in
RDP supplements, without adversely affecting intake and/or fermentation and digestive
processes. The control treatment provided all of the RDP in the form of calcium caseinate
(90% CP; 100% rumen degradable). The percentages of supplemental RDP from urea in the
other treatments were 25, 50, 75 and 100%. The 100% urea treatment was balanced with
maize starch to contain 40% CP and all other treatments received the same amount (150 gld)
of starch. Intake of forage OM showed a weak decreasing trend (linear; P = .16) with increasing urea levels. Ruminal digestibilities of OM and NDF were not affected (P ;;::.:18) by
urea level. Increasing urea levels resulted in linearly reduced total tract OM and NDF
digestibilities (P ~ .10). As a result, DOMI declined (linear; P < .01) with increasing
proportions of urea. Effects of increasing urea proportions on duodenal N flow, microbial
efficiency and fluid dilution rate were minimal. Ruminal NH3-N tended to increase
quadratically with increasing urea levels (P = .l4). Total VFA concentration decreased
linearly (P = .03), while rumen pH increased in a linear manner (P = .08) with increasing
urea proportions. Branched-chain volatile fatty acids (BCVFA's) and valerate decreased
linearly (P ~ .05) with increasing urea levels, while other VFA's and the acetate:propionate
ratio were generally not affected by treatment (P ;;:::.16). It appears as though ruminal and
total tract OM and NDF digestibility criteria, as well as DOMI reached maximum values at
substituting 25% of casein for urea. It is therefore concluded that replacing 25% of casein
with urea in RDP supplements, will maintain effective utilisation of low-quality forages by
sheep. / AFRIKAANSE OPSOMMING: Ontwikkelende lande, insluitend Suid-Afrika, word gekenmerk deur 'n vmmge
bevolkingsaanwas. Dit lei tot 'n verhoogde vraag na voedsel, wat op 'n gevolglik kleinerwordende
beskikbare kommersiële lanbbou-area geproduseer moet word. Die
doeltreffendheid van produksieprosesse in die landbousektor moet dus noodgedwonge
verbeter word. Die oorgrootte meerderheid van die bevolkings in ontwikkelende lande is
ongeletterd en armoede en hongersnood is soms 'n algemene verskynsel. Veekundiges word
dus gekonfronteer met die uitdaging en verantwoordelikheid om bekostigbare, hoë kwaliteit
voedsel aan hierdie mense te voorsien.
Een van die mees doeltreffende metodes om hierdie probleem aan te spreek, is om die
benutting van lae kwaliteit, hoë-vesel voerbronne, bv. oesreste en droë grasweidings te
verhoog. In die winterreënstreek van Suid-Afrika alleen, is 460 000 ha koringstrooi jaarliks
beskikbaar. Herkouers beskik oor die besondere vermoë om die relatief onbeskikbare energie
(sellulose, hemi-sellulose en pektien) in die veselkomponent van hierdie lae kwaliteit voere te
benut. Verskeie faktore, waarvan 'n N-tekort die mees prominente is, beperk egter die
benutting van hierdie voerbronne. Die uitdaging is dus om die herkouer se vermoë om
hierdie voere te benut, te optimaliseer. Sodoende word 'n geredelik beskikbare, onderbenutte
en relatief goedkoop voerbron omgeskakel in hoë kwaliteit proteïen vir menslike gebruik. Die N-aanvullingsbehoefte om die fermentasie- en verteringsprosesse van die herkouerdier te
optimaliseer moet dus bepaal word, sodat die N-tekort in herkouers, wat soortgelyke
weidings benut, reggestel kan word. Gevolglik was die doel met die eerste proef om die
behoefte aan rumen degradeerbare proteïen-(RDP)-aanvulling, vir die maksimum inname van
verteerbare organiese materiaal (VOM) van Dohne Merino skape wat koringstrooi ontvang,
te bepaal. Weens die hoë koste van natuurlike proteïenaanvulling, was die doel met die
tweede proef om die hoeveelheid ware proteïen in RDP-aanvullings, vir Dohne Merino skape
wat koringstrooi ontvang, wat met nie-proteïen stikstof (NPN) vervang kan word, te bepaal.
In beide eksperimente het die diere ad libitum toegang tot koringstrooi (3.2% RP;
74.2% NBV) en water gehad. In die eerste proefis RDP (kalsiumkaseïnaat; 90% RP; 100%
rumen degradeerbaar) teen 07hOOen 19hOOintraruminaal toegedien, teen die volgende peile:
0, 40, 80, 120 en 160 gld. Inname, fermentasie en vertering is gemonitor om die RDP
behoefte vir die maksimum inname van VOM te bepaal. Verteerbare OM-inname het 'n
stygende kwadratiese tendens (P < .01) getoon met verhoogde RDP-peile en het 'n
maksimum bereik by 'n aanvullingspeil van 3.15 g RDPlkg metaboliese liggaamsmassa
(LM·75
) of 11.6% van VOM. Organiese materiaalinname vanaf koringstrooi het geneig om
kwadraties toe te neem (P = .15) met verhoogde RDP-peile. Mikrobiese stikstof-(MN)-vloei
na die duodenum en mikrobiese effektiwiteit het kwadraties toegeneem (P :::;.;04) en vloeistof
deurvloeitempo het 'n neiging vir 'n kwadratiese toename (P = .15) met verhoogde RDPpeile
getoon. Rumen-ammoniakstikstof (NH3-N) en vlugtige vetsuur-(VVS)-konsentrasies
het lineêr toegeneem (P :::;.;07), terwyl rumen pH 'n wisselende reaksie (kubies; P = .08) met
stygende RDP-peile getoon het. Verteerbare OM-inname en benutting van koringstrooi is
verbeter deur stygende peile van RDP aanvulling by Dohne Merino hamels.
In die tweede proef is kaseïen op 'n iso-stikstof basis met verskillende ureumpeile, vanaf
o - 100%, vervang. Omdat ureum baie goedkoper is as natuurlike proteïen, was die doel van
die tweede proef om die hoeveelheid natuurlike proteïen in RDP-aanvullings te bepaal wat
met ureum vervang kan word, sonder om inname, fermentasie en vertering te benadeel. Die
kontrolebehandeling het 100% van die RDP in die vorm van kalsiumkaseïnaat (90% RP;
100% rumen degradeerbaar) voorsien, terwyl ureum in die ander behandelings onderskeidelik
25, 50, 75 en 100% van die kaseïen-N vervang het. Die 100% ureumbehandeling is met
mieliestysel tot 40% RP gebalanseer en dieselfde hoeveelheid stysel (150 gld) is by al die ander behandelings ingesluit, om moontlike effekte van stysel op rumenfermentasie te
elimineer. Organiese materiaalinname vanafkoringstrooi het 'n swak dalende tendens getoon
met stygende ureum insluitingsvlakke (lineêr; P = .16). Rumenverteerbaarheid van OM en
neutraal bestande vesel (NBV) is nie deur die ureumpeil beïnvloed nie (P ;;:: .18).
Toenemende ureumpeile het gelei tot 'n lineêre afname in totale kanaal OM en NBVverteerbaarheid
(P ~ .10). Gevolglik het VOM inname lineêr afgeneem (P < .01) met
stygende ureum insluitingspeile. Die effek van behandeling op duodenale N-vloei,
mikrobiese effektiwiteit en vloeistof deurvloeitempo was minimaal. Rumenammoniakstikstof-(
NH3-N)-konsentrasie het 'n stygende kwadratiese tendens getoon
(P = .14) met toenemende ureum peile. Totale vlugtige vetsuur-(VVS)-konsentrasies het
lineêr gedaal (P = .03), terwyl rumen pH lineêr toegeneem het (P = .08) met stygende ureum
insluitingsvlakke. Vertakte ketting VVS' e en valeriaansuurkonsentrasies het lineêr gedaal
(P ~ .05) met stygende ureumpeile, terwyl die ander VVS' e en die
asynsuur:propioonsuurverhouding oor die algemeen nie deur behandeling beïnvloed N; nie
(P ;;:: .16). Dit blyk asof VOM inname, sowel as rumen- en totale kanaal
verteerbaarheidsmaatstawwe, by 25% vervanging van kaseïen-N met ureum-N 'n maksimum
bereik het. Die gevolgtrekking is gemaak dat die doeltreffende benutting van lae kwaliteit
ruvoere deur skape, gehandhaaf sal word deur 25% van die ware proteïen in RDP-aanvullings
met ureum te vervang.
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Comparison of two CYP17 isoforms : implications for cortisol production in the South African MerinoHough, Denise 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This study describes:
• the comparison of the enzymatic activities of the two ovine cytochrome P450 17 -
hydroxylase/17,20-lyase (CYP17) isoforms expressed in non-steroidogenic COS-1 cells.
The Km and Vmax values for the metabolism of pregnenolone and progesterone were
determined, while time-dependent metabolism of pregnenolone, 17-hydroxypregenolone,
progesterone and 17-hydroxyprogesterone was also reported. The cloning and sequencing of
ovine cytochrome b5 is reported and was co-expressed with CYP17. The results showed that
the wild type 1 (WT1) isoform of ovine CYP17 produce more cortisol precursors than the
wild type 2 (WT2) isoform;
• the analysis of the frequency distribution of the CYP17 genotypes within a South African
Merino population, which were divergently selected for (H-line) or against (L-line) the
ability of a ewe to rear multiple offspring per birthing opportunity. It was observed that the
CYP17 frequency distribution was the same within the H- and L-line, with 78.3 %
heterozygous WT1/WT2 and 21.7 % homozygous WT1/WT1. No homozygous WT2/WT2
individuals were identified;
• the development of a UPLC-MS/MS method for the separation and quantification of all
thirteen adrenal steroids that are produced in the adrenal gland;
• the relative contribution of the CYP17 genotypes in the total steroidogenic output in adult
adrenocortical cells from the adrenal glands of H- and L-line sheep, with particular emphasis
on cortisol production. The adrenocortical cells from the H-line sheep showed a marked
higher cortisol production than the L-line, while adrenocortical cells from homozygous
WT1/WT1 sheep also produced more cortisol than heterozygous WT1/WT2 sheep;
• the blood cortisol responses upon the stimulation of the HPA axis by insulin induced
hypoglycaemia of the H- and L-line sheep with known CYP17 genotypes. It was observed
that the CYP17 genotype and selection line are important factors affecting the cortisol
responses of sheep, where L-line heterozygous WT1/WT2 sheep showed the lowest cortisol
response and glucose recovery; • the association of the CYP17 genotype with behavioural responses of H- and L-line sheep to
flock isolation stress, as well as the association of the CYP17 genotype with ewe
reproduction and lamb output. While reproduction seemed to be unaffected by the CYP17
genotype, the behavioural stress responses of sheep to flock isolation correlated with the
CYP17 genotype, where the heterozygous WT1/WT2 genotype was associated with a wilder
nature. / AFRIKAANSE OPSOMMING: Hierdie studie ondersoek:
• die vergelyking van die ensiemaktiwiteite vir twee isoforme van skaap sitochroom P450
17 -hidroksilase/17,20-liase (CYP17), wat uitgedruk was in nie-steroïed genererende COS-
1 selle. Die Km and Vmax waardes was bepaal vir die metabolisme van pregnenoloon en
progesteroon, terwyl die tyd-afhanklike metabolisme van pregnenoloon, 17-
hidroksiepregnenoloon, progesteroon en 17-hidroksieprogesteroon ook gerapporteer word.
Die klonering en volgorde bepaling van skaap sitochroom b5 was gedoen en gevolglik was
sitochroom b5 saam met CYP17 uitgedruk in COS-1 selle. Die resultate het gewys dat wilde
tipe 1 (WT1) meer voorlopers van kortisol produseer as wilde tipe 2 (WT2);
• die frekwensie distrubusie van die CYP17 genotipes in ‘n Suid-Afrikaanse Merino
populasie, waar skape in teenoorgestelde rigtings geselekteer was vir (H-lyn) of teen (L-lyn)
die vermoë van ‘n ooi om geboorte te gee aan veelvoudige lammers per lamgeleentheid. Die
frekwensie distrubusie van CYP17 was dieselfde in beide die H- en L-lyn, waar 78.3 % van
die populasie heterosigoties WT1/WT2 en 21.7 % homosigoties WT1/WT1 was. Geen
homosigote WT2/WT2 individue was geïdentifiseer nie;
• die ontwikkeling van ‘n UPLC-MS/MS metode vir die skeiding en kwantifisering van al
dertien steroïede wat natuurlik geproduseer word in die bynier van die skaap;
• die relatiewe bydrae van die CYP17 isoforme tot die totale steroïedale uitsette vanuit die
bynier kortex selle, vanaf die byniere van H- en L-lyn skape, waar klem geplaas word op die
produksie van kortisol. Die bynierselle van die H-lyn skape het aansienlik meer kortisol
produseer as die L-lyn, terwyl die bynierselle van die homosigotiese WT1/WT1 skape ook
meer kortisol produseer het as heterosigotiese WT1/WT2 skape;
• die bloed kortisol in reaksie tot die stimulering van die hipotalamus-hipofise-adrenale aksis,
deur insulien geïnduseerde hipoglisemiese stress, in skape van die H- en L-lyne met bekende
CYP17 genotipes. Dit was gevind dat die kortisol reaksie geaffekteer word deur beide die
CYP17 genotipe en seleksie lyn, waar L-lyn heterosigotiese WT1/WT2 skape die minste
kortisol geproduseer het en die stadigste herstel van glukose vlakke getoon het; • die assosiasie tussen die CYP17 genotipe en die gedrags reaksies op trop-isolasie, sowel as
ooi-reproduksie en lamuitset, van die H- en L-lyn skape. Die reproduksie parameters was
onafhanklik van die CYP17 genotipe, terwyl ‘n sterk assosiasie gevind was tussen die
CYP17 genotipe en gedrags reaksies op trop-isolasie. Die heterosigotiese WT1/WT2 skape
het ‘n wilder natuur getoon gedurende trop-isolasie in vergelyking met homosigotiese
WT1/WT1 skape.
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La búsqueda de la identidad a través de la conciencia mítica del personaje en El heredero de José María MerinoBecerra Gálvez, Macarena January 2007 (has links)
Informe de Seminario para optar al grado de Licenciado en Lengua y Literatura Hispánica mención Literatura
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Isolation and characterisation of genes expressed in the wool follicleRelf, Bronwyn Lee, University of Western Sydney, School of Science January 1999 (has links)
Wool from Merino sheep is an important component of the Australian economy. However, little is known of the mechanisms within the wool follicle that regulate fibre production. The aim of the research described here was to identify and characterise some of the genes expressed in the follicle.A highly expressed gene has been identified from skin and sequenced. The information obtained on this gene suggests that it might be of use in future transgenic studies. Two cDNA libraries were constructed. The first was constructed using small amounts of total RNA from skin and PCR methodology, following a published method. A second cDNA library was then produced from adult mid-flank skin using a commercially available kit. A pool of 420 potential wool follicle specific transcripts were identified from this adult mid-flank skin cDNA library using a combination of differential and subtractive screening. Clone 1-25 was chosen as the focus for the remaining work described in this thesis. Expression of clone 1-25 was detected at all stages of wool follicle development and was localised to the wool follicle bulb, inner root sheath, outer root sheath, epidermis, but not the dermis or dermal papilla. The function of clone 1-25 is as yet unknown. However, from its expression in the wool follicle, and studies by other groups, it appears that it may play a role in inducing differentiation / Doctor of Philosophy (PhD) (Biological Sciences)
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Effect of peri-conceptional feed intake on early embryo development and fetal growth in the Merino ewe / Muhammad Azam Kakar.Kakar, Muhammad Azam January 2003 (has links)
"March 2003" / Includes bibliographical references (leaves 237-297) / ix, 297 leaves : ill. (some col.), plates (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Animal Science, 2005
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A study of factors affecting embryonic, fetal and lamb survival in high fecundity merino ewesKleemann, D. O. January 1994 (has links) (PDF)
Bibliography : leaves 120-133. Defines the sources of reproductive wastage in FecB FecÊ Booroola Merino x South Australian Merino ewes and examines factors associated with the survival of embryos, fetuses and lambs with the aim of improving net reproduction efficiency. Experiments were conducted to define the problem; to examine factors affecting embryonic and fetal loss; and, to investigate factors influencing wastage at lambing.
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Pubertal development in the merino ram lambs and immunization against oestrogensAuclair, Dyane. January 1993 (has links) (PDF)
Bibliography: leaves 281-316. Presents investigations on pubertal development in South Australian merino ram lambs and examines the effect of active and passive immunizations against oestradiol-17ℓ or oestrone on testicular maturation.
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El retorno renovador a la tradición : la memoria colectiva en la narrativa española (1973-1994) /Diakow, Anna Gabriela. January 2001 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Romance Languages and Literatures, August 2001. / Includes bibliographical references. Also available on the Internet.
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The following (walking) ability of the neonatal lamb / by Kwame Oppong-Anane. / Walking ability of the neonatal lamb / Study of the behavioural, metabolic and physiological responses of the neonatal lamb to walkingOppong-Anane, Kwame January 1991 (has links)
Includes bibliographical references (leaves 276-2970. / xiii, 297 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigations presented involve 18 hour to 5 day old South Australian merino lambs. Some twin lambs were available for comparative studies. Examines the relationship between the strength of ewe-lamb bond and the lamb's ability to follow the mother, the energy availability and usage in the lamb, particularly for locomotion, and the metabolic and cardiorespiratory responses to locomotion. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1992
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