The South African ostrich industry is presently characterised by a drastic decline in the slaughter price of slaughter birds, due to the drop in the price of meat as well as leather. As a result, the economic viability of ostrich farming is severely hampered by these developments, and many generally accepted industry practices have to be reviewed. Among the practices under review is the possibility of slaughtering ostriches at an earlier age than the traditional slaughter age of 12 - 14 months, in order to minimise feed costs and the incidence of damage to the skin. However, little information is available on the effect of the slaughter age on the yield and quality of the economically important end-products. The effect of slaughter age on production and the economic viability of a commercially intensive ostrich production system was consequently evaluated in a completely randomised experimental design involving two batches (n= 81 and n= 94) of ostriches. The experiments took place at Kromme Rhee experimental farm of the Elsenburg Research Centre near Stellenbosch. The birds were subject to experimental treatment at the age of 4 months (n= 81, from May 2004 to March 2005) and 6 months (n= 94, from August 2004 to August 2005) respectively. The ostriches were randomly divided into 10 groups of between 16 and 20 birds per group. Standard production practices, as applied in an intensive ostrich production unit, were implemented. Clean drinking water and self-mixed grower diet (min 15 percent crude protein, 0.68 percent lysine and 11.4 MJ ME per kg feed) and finisher diet (min 14 percent crude protein, 0.55 percent lysine and 9.8 MJ ME per kg feed) were provided ad libitum to the birds. Birds were slaughtered at the ages of 8.5, 10.5, 12.5, 14.5, and 16.5 months respectively. Data on feed intake and yields of cold carcass, crust skin size, skin grade and total feathers was recorded for birds slaughtered at the respective ages. Data was analysed according to the analysis of variances. Values for meat yield, skin size yield and feed intake were predicted by regression analysis based on experimental values. Industry figures and norms were used as proxy for other production inputs and costs. A gross margin type analysis was performed to evaluate the effect of different slaughter ages on the profitability of each production system. There was a positive correlation between age and feed intake (r2= 0.40), slaughter weight (r2= 0.97), cold carcass yield (r2= 0.48), skin surface area (r2= 0.39), skin grade (r2= 0.19) and total yield of feathers (r2= 0.29). The dry skin grade showed deterioration as slaughter age was prolonged. Highly significant differences (P< 0.01) in slaughter weight, cold carcass yield, skin surface area, dry skin grade and total feathers were detected at the different slaughter ages. There were no significant differences (P> 0.05) with respect to gender for slaughter weight, skin surface area and dry skin grade within the different age groups. Males had significantly higher (P< 0.05) cold carcass yield and total feather yield than their female counterparts. From this study it can be concluded that an increase in slaughter age significantly increases feed intake, slaughter weight, cold carcass yield, and skin surface area. It is also clear that an increase in slaughter age can be detrimental to dry skin grade. The relative income contribution of the three main products (skin: meat: feathers) occurred in a ratio of 47:53:0, 52:47:1, 47:50:3, 44:51:5, 39:56:5 at the respective slaughter ages. Total income revealed an increase of 26 percent from 8.5 to 10.5 months slaughtering, an increase of 4 percent between 10.5 and 12.5 months, and an increase of 11 percent between 12.5 and 14.5 months. The income dropped by 0.3 percent between 14.5 and 16.5 months slaughtering. Total costs increased with slaughter age, particularly feed costs which showed an increase (at a decreasing rate) between the different slaughter ages. The margin above specified cost per bird was the highest for birds slaughtered at the age of 10.5 months. The margin above cost showed a steady decline as birds were slaughtered at higher ages. Slaughtering at 16.5 months revealed a negative margin. To compare the effect of differences in time span on different slaughter age regimes, margin above costs for each system over 5 years were discounted to a present value. In this study, with current feed costs and income from end products, slaughtering at 10.5 months revealed the highest present value for the margin above cost. Furthermore, slaughtering at 16.5 months revealed a negative present value on the margin above cost after 5 years. Financial viability calculations are relevant and valid for data obtained in this case study. Financial viability is however case-specific and may vary between producers, depending on their individual management practices, production systems and cost structures. Results from this study may be of significant value to managerial decision-making in the ostrich industry.

Bakgrund: 90-talister i Sverige står inför två tuffa val: att arbeta fram till 70–71-års åldereller att offra vissa angelägenheter idag för att kunna spara en relativt stor summa av sinlön till den framtida pensionen. Dagens pensionärer visar ett missnöje för sin ekonomiskasituation och med tanke på de sämre förutsättningarna som föreligger för 90-talister gällerdet att ta tag i pensionsförberedelser i tid för att ha någon chans att uppnå entillfredsställande pensionssituation. Trots det har det visat sig att unga vuxna skjuter framproblemet till framtiden och prioriterar mer kortsiktiga mål, samtidigt som de förväntarsig en tillfredsställande pensionssituation. Syfte: Studiens syfte är att, med utgångspunkt i en analys av de beteendepsykologiskafallgroparna övertro, ostrich effect och influerande av andra, skapa en djupare förståelseför det potentiella gapet mellan 90-talisters pensionsförväntningar och potentiellapensionssituation. Metod: För att uppfylla studiens syfte och få en djupare förståelse för hur debeteendepsykologiska fallgroparna influerar det potentiella gapet valdes en kvalitativmetod med tio semistrukturerade intervjuer. Genom intervjuerna kunde författarna få enbättre insikt i respondenternas subjektiva verklighet. Slutsats: Studien visar att det i många fall finns ett gap mellan pensionsförväntningar ochen potentiell pensionssituation och att faktorer inom de utvalda beteendepsykologiskafallgroparna både kan bidra till ett ökat och minskat gap. Gapet är stort hos majoritetenav respondenterna, på grund av de genomgående höga förväntningarna. Trots attförväntningarna ofta är för höga i jämförelse med respondenternas förutsättningar ochpensionsförberedelser, går det att skilja på ett positivt och negativt gap. Det viktigaste äratt börja spara i tid, och faktorer såsom självförtroende på egen förmåga och att ta hjälpav en finansiell rådgivare främjar ett pensionssparande och bidrar på så sätt till ett positivtgap, medan faktorer som att tro sig vara bättre än andra och prokrastinering hämmaragerandet och bidrar till ett negativt gap. / Background: Young adults in Sweden face two tough choices: to work until the age of70-71 or to sacrifice certain wants today in order to save a relatively large amount of theirsalary for future retirement. Today's pensioners show dissatisfaction with their financialsituation and, given the inferior conditions that exist for young adults, it is important tostart with retirement preparations in time to have any chance of achieving a satisfactorypension situation. Nevertheless, it has been shown that young adults postpone the problemuntil the future and prioritize more short-term goals, while expecting a satisfactoryretirement situation. Purpose: The purpose of this study is to, based on an analysis of the behavioralpsychological bias of overconfidence, ostrich effect and influence of others, create adeeper understanding of the potential gap between young adults’ retirement expectationsand potential retirement situation. Methodology: To fulfill the purpose of the study and gain a deeper understanding of howthe behavioral psychological biases influence the potential gap, a qualitative method withten semi-structured interviews was chosen. Through the interviews, the authors were ableto gain a better insight into the subjective reality of the respondents. Conclusion: The study shows that, in many cases, there is a gap between retirementexpectations and a potential retirement situation and that factors within the selectedbehavioral psychological biases can contribute to both an increased and a decreased gap.The majority of the respondents have a large gap, due to the consistently highexpectations. Despite the fact that the expectations are often too high in comparison withthe respondents’ conditions and retirement preparations, it is possible to distinguishbetween a positive and a negative gap. The most important thing is to start retirementsavings on time, and factors such as self confidence and taking the help of a financialadviser promote retirement saving and thus contribute to a positive gap, while factorssuch as believing oneself to be better than others and procrastination inhibits action andcontributes to a negative gap.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The South African Ostrich industry was established more than 100 years ago. Despite appreciable fluctuations and modifications in demand, the industry perseveres, with meat and leather as the current primary driving force. Low and variable early chick survival is globally considered as a major constraint in the industry. In spite of obvious welfare and production implications, research findings concerning ostrich chick survival are scant. Four studies involving chick survival to 24 weeks post hatch were thus performed. South African Black ostrich (Struthio camelus var. domesticus) data obtained from a commercial pair-bred ostrich flock maintained at the Oudtshoorn Experimental Farm, South Africa comprising 10418 records were utilized to run a series of single- and multiple-trait binomial analyses using either linear models (ASREML) or threshold models (Monte Carlo Markov Chain methods, employing Gibbs sampling software) respectively. Suitable fixed and random effect models together with variance and (co)variance components were derived from these analyses. Ostrich chick survival to 24 weeks post hatch was low (28%) with a large environmental component. Preincubation storage time only affected 0 to 3 week survival, while incubator had a significant effect on cumulative survival traits to 24 weeks as well as on 13 to 24 week survival. Female chicks outperformed males at 0 to 12 weeks, 0 to 24 weeks, 4 to 12 weeks and 13 to 24 weeks with regard to survival. Hen age was significant for all traits except survival during the first week as well as for survival from 13 to 24 weeks post hatch. All analyses exhibited comparable low heritability estimates for all survival traits except for 0 to 1 week survival and 13 to 24 week survival (h2 = 0.12 and 0.10; m2 = 0.08 and 0.07 respectively) which demonstrated higher additive genetic and maternal components when threshold models, using Gibbs sampling algorithms, were employed. Neither moisture loss nor day of external pipping exhibited notable additive genetic correlations with any of the estimated survival traits. Day-old chick weight demonstrated a low correlation with early chick survival (rg = 0.24 ± 0.19) with heavier chicks tending to have a higher survival probability. The effects of rearing method on early chick survival and growth were also investigated. Comparisons between chicks reared and fostered by adult ostriches in a semiextensive environment and chicks imprinted onto humans under an intensive system and between regular human handling in an intensive rearing system and the standard farm protocol of an intensive rearing system were made. No difference in the early chick survival to 3 weeks post hatch of chicks reared by foster parents and those chicks imprinted onto humans was demonstrated. At later ages, those chicks reared by foster parents outperformed human imprinted chicks. Human imprinted chicks exposed to regular handling demonstrate an enhanced early survival when compared to chicks exposed to conventional rearing protocol in intensive systems. The study is seen to provide guidance for further research on this topic. / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse volstruisbedryf is meer as 100 jaar gelede gevestig. Die bedryf is volhoubaar, ten spyte van ‘n fluktuerende aanvraag na volstruisprodukte. Vleis en leer is tans die produkte wat die meeste tot die inkomste van boere bydra. Lae en wisselende kuikenoorlewing is ‘n belangrike knelpunt in die bedryf. Navorsingsuitsette rakende kuikenoorlewing is skaars, ten spyte van ooglopende welsyns- en produksie implikasies. Kuikenoorlewing tot en met 24 weke na uitbroei is dus in vier afsondelike studies ondersoek. Data van 10418 kuikens uit ‘n kommersiële broeipaargeteelde Suid-Afrikaanse Swart (Struthio camelus var. domesticus) kudde op die Oudtshoorn Navorsingsplaas, Suid-Afrika is gebruik om enkel- en meervoudige eienskappe met of liniêre modelle (ASREML) of drempelwaarde modelle (Monte Carlo Markov Ketting metodes, met Gibbs monstering sagteware) te pas. Die metodes is gebruik om toepaslike vaste- en toevalseffekte modelle saam met (ko)variansie komponente te bekom. Kuikenoorlewing tot 24 weke na uitbroei was laag (28%), met ‘n groot omgewingsbydraende komponent. Stoor van eiers voor pak het slegs kuikenoorlewing van 0 tot 3 weke beïnvloed, terwyl die broeikas wat gebruik is ‘n betekenisvolle invloed op kuikenoorlewing tot 24 weke ouderdom, sowel as op -oorlewing van 13 tot 24 weke gehad het. Wyfiekuikens het beter oorleef as mannetjie kuikens vir oorlewing gemeet van 0 tot 12 weke, 0 tot 24 weke, 4 tot 12 weke en van 13 tot 24 weke. Broeiwyfie ouderdom het ‘n betekenisvolle invloed op kuikenoorlewing in die eerste week na uitbroei en van 13 tot 24 weke na uitbroei, gehad. Kuikenoorlewing was relatief laag oorerflik, behalwe vir oorlewing van 0 tot 1 week en vir oorlewing van 13 tot 24 weke van ouderdom (h2 = 0.12 en 0.10; m2 = 0.08 en 0.07 onderskeidelik). Drempelwaarde modelle met Gibbs monstering algoritmes het hoër additiewe en maternale variansie verhoudings in vergelyking met liniêre modelle aangedui. Genetiese korrelasies van vogverlies en die dag van uitwendige pik met kuikenoorlewing was oor die algemeen onbeduidend. Dagoudkuikengewig is laag gekorreleerd met vroeë kuikenoorlewing (rg = 0.24 ± 0.19), met swaarder kuikens wat oor die algemeen beter oorleef. Die gevolge van verskillende grootmaak metodes op vroeë kuikenoorlewing en -groei is ook ondersoek. Vergelykings tussen kuikens grootgemaak deur volwasse volstruise as pleegouers in ‘n semi-intensiewe omgewing en kuikens grootgemaak deur mense onder ‘n intensiewe stelsel en tussen kuikens grootgemaak deur gewone menslike hantering in ‘n intensiewe grootmaak sisteem onder standard plaas protokol was bestudeer. Geen verskille was gevind in vroeë kuikenoorlewing tot 3 weke na uitbroei, van die kuikens grootgemaak deur volwasse volstruise en tussen die kuikens grootgemaak deur mense . By latere ouderdomme, het die kuikens wat grootgemaak was deur volwasse volstruise beter oorlewing getoon as die kuikens grootgemaak deur mense. Kuikens grootgemaak deur mense wat blootgestel was aan gereelde hantering het verhoogde vroeë oorlewing getoon in vergelyking met kuikens grootgemaak deur konvensionele grootmaak protokol in intensiewe stelsels. Die studie kan dus beskou word om leiding te verskaf vir verdere navorsing oor hierdie onderwerp.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The production and export of ostrich meat from southern Africa, to especially the European Union, are increasing rapidly due to the healthy nature of ostrich meat. The European Union has very high standards when importing food products, and it is inevitable that more emphasis is being placed on the production of high quality ostrich meat. Another aspect also of concern to consumers, is the welfare of animals prior to slaughter, and this forces producers to look at ways to decrease stress of animals during the ante-mortem period. Research regarding the effect of stress during the ante-mortem period, and as a result, on meat quality, haematology and weight loss in ostriches, is lacking and thus the purpose of this study was to investigate the effect of various transport distances, travel conditions and different birds on these factors. Ante-mortem stress was measured using serum corticosterone levels (ng/ml), heterophil: lymphocyte (H:L) ratio, white blood cell (WBC) count, aspartate aminotransferase (AST) and creatine kinase (CK), as well as the rate and extent of pH decline in the M. gastrocnemius. Special emphasis was also placed on the meat quality parameters drip loss, cooking loss, colour and Warner-Bratzler shear force (kg/1.27 cm diameter). Live weight losses, as well as carcass weight and weight of bruises cut off from each bird were also recorded during various stages of the trials. The effect of transport distance on the meat quality of ostriches was investigated. Ultimate pHu measurements were taken at 24 hours post-mortem. The muscles of the ostriches from the control group (i.e. birds that were not transported prior to slaughter) had a lower mean pHu (5.77 ± 0.053) than birds that travelled 60 (5.93 ± 0.053) and 600 km (6.11 ± 0.053), respectively. Differences in meat drip loss percentage were also observed between the three treatments. The birds in the control group (0.40 ± 0.07 %) had the lowest meat drip loss percentage compared to the birds that travelled 60 km (treatment C) (1.36 ± 0.07 %) and 600 km (treatment B) (0.97 ± 0.07 %), respectively, to a commcerical ostrich abattoir. Ostriches that were transported for 600 km (8.13 ± 1.16 %) had a greater percentage live weight loss during the antemortem period than birds that travelled a distance of 60 km (2.4 ± 2.185 %) to the abattoir, although both groups were deprived of feed for the same period. When the haematology of the groups that travelled different distances was compared at various time intervals in the ante-mortem period, both groups of birds experienced significant increases in WBC, s-AST and s-CK. An increased H:L ratio from pre-transport to post-transport was only evident in the birds that travelled 600 km (treatment B). However, the birds that travelled 60 km were the only group of birds that had significant elevated serum corticosterone levels during the ante-mortem period. The increase in the various blood parameters indicates severe physical stress, which negatively affected meat quality. Another trial also investigated the effect of various farming systems and transport on meat quality and bruising of ostrich carcasses. Ostriches were raised in three different farming systems, i.e. feedlot -, semiintensive - and free range conditions. Other factors that could maybe impact on stress susceptibility, such as road conditions, floorspace and floor type were also investigated. A significant difference in meat pHu was found between ostriches that were raised in a feedlot (5.95 ± 0.018) and semi-intensive (6.04 ± 0.033) environment. The feedlot birds also had the greatest percentage of carcass weight removed due to bruising. The free range birds were the birds that had the lowest floor density per birds and also had the least amount of bruising on their carcasses. Incidently the other two groups (feedlot and semi intensive) were the birds that travelled on the same type of road (mountain pass) in a truck with rubber flooring whilst the free range birds travelled on a straight road in trucks with metal grid floors.The results indicate that the type of farming system didn’t have a significant influence on meat quality of ostriches, but that factors such as road conditions, flooring and bird density did play a significant role in the incidence of bruises and injuries obtained during transport. / AFRIKAANSE OPSOMMING: Die produksie en uitvoer van volstruisvleis vanuit suidelike Afrika, na veral die Europese Unie, is gedurig aan die toeneem as gevolg van die gesonde aard van volstruisvleis. Die Europese Unie het baie hoë standaarde wanneer dit kom by die invoer van voedselprodukte en dit is onvermydelik dat meer klem op die produksie van hoë gehalte volstruisvleis gelê word. ʼn Ander aspek wat ook kommer wek by verbruikers is die welstand van diere voor slagting en hierdie aspek noodsaak produsente om te kyk na maniere om stres te beperk tydens die periode voor slagting. Navorsing rakende die effek van stres tydens die ante-mortem periode, asook vleiskwaliteit, hematologie en gewigsverlies in volstruise as gevolg van vervoer, ontbreek. Die doel van die studie was dus om die invloed van verskillende vervoerafstande, vervoersomstandighede en tipe produksiesisteme op volstruise se stresrespons te ondersoek. Die omvang van ante-mortem stres is bepaal deur die serum-kortikosteroon vlakke (ng/ml), heterofiel: limfosiet (H:L) ratio, witbloedsel (WBS) telling, aspartaat aminotransferase AST en creatien kinase CK, asook die tempo en vlak van pH-daling in die M. gastrocnemius, te meet. Spesiale klem is gelê op die vleisgehalte parameters kookverlies, drupverlies, kleur en Warner-Bratzler-skeurwaardes (kg/1.27 cm deursnee). Gewigsverlies is aangeteken op verskillende stadiums tydens die proewe. Karkasgewigte en die hoeveelheid gewig afgesny van elke volstruiskarkas a.g.v. kneusings is ook bepaal. Die eerste studie het die invloed van vervoerafstand op vleiskwaliteit van slagvolstruise ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies, taaiheid en kleur is ondersoek. Die pHu metings is op 24 uur post-mortem geneem. Slagvolstruise in die kontrole groep (d.i. -volstruise wat nie voor slagting vervoer is nie) het ’n laer vleis pHu (5.77 ± 0.05) gehad as voëls wat onderskeidelik 60 km (5.93 ± 0.05) en 600 km (6.11 ± 0.05) ver vervoer is. Verskille in persentasie dripverlies is gesien tussen die vleis van die voëls wat nie vervoer is nie (0.40 ± 0.07 %) en die voëls wat 60 km (1.36 ± 0.07 %) en 600 km ver (0.97 ± 0.07 %) onderskeidelik vervoer is. Volstruise wat vir 600 km (8.13 ± 1.16 %) vervoer is, het ‘n groter persentasie lewende gewig tydens die ante-mortem periode as voëls wat 60 km (2.4 ± 2.19 %) ver vervoer is na die abattoir, verloor, al was beide groepe weerhou van voer vir dieselfde tydperk. Beide groepe wat vervoer is (60 en 600 km) het merkbare toenames in witbloedsel (WBS) tellings, s-AST’s en s-CK’s getoon tydens die ante-mortem periode. Daar is slegs ʼn toename in H:L ratio (ʼn indikator van stres) van voor vervoer tot na vervoer gesien in die voëls wat 600 km vervoer is. Daarteenoor was die voëls wat slegs 60 km vervoer is die enigste voëls wat ʼn toename in korticosteroon vlakke getoon het gedurende die ante-mortem periode. Die toenames is heel moontlik ‘n aanduiding van erge fisiese stres wat ‘n negatiewe effek op vleiskwaliteit het. Die tweede studie het die effek van verskillende produksiesisteme en die stress respons van die verskillende groepe slagvolstuise op vervoer ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies en taaiheid is ondersoek. Die hoeveelheid kneusings per volstruis is ook gemeet. Daar was ‘n beduidende verskil (P = 0.009) tussen die pHu van die voerkraal (5.95 ± 0.018) en semi- intensiewe (6.04 ± 0.033) volstruise. Die voerkraal volstruise se vleis het die grootste drip- en kookverliese gehad in vergelyking met die ander twee groepe (semi-intensiewe en ekstensiewe) terwyl die ekstensiewe volstruise die taaiste vleis gehad het. Die voerkraalvoëls het ook die grootste persentasie karkasgewig verloor a.g.v. kneusings wat afgesny is. Die ekstensiewe voëls het die laagste vloer digtheid per volstruis gehad asook die minste kneusings. Die ander twee groepe (voerkraal en semi intensief) was die groepe wat op dieselfde pad vervoer is (bergpas) in vragmotors wat rubber vloere gehad het terwyl die ekstensiewe voêls op ‘n reguit pad vervoer is in ‘n vragmotor met ‘n metaal oppervlakte. Die resultate van die studie is ‘n aanduiding dat die tipe plaassisteem nie ‘n groot impak op die hoeveelheid akute stres ervaar deur die voëls tydens vervoer gehad het of gevolglik op die vleiskwaliteit van die volstruise nie, maar dat faktore soos pad toestand, tipe vloer en voëldigtheid wel ‘n wesenlike rol speel in die voorkoms van kneusings en beserings opgedoen tydens vervoer.

Thesis (PhD(Agric) Animal Sciences))--University of Stellenbosch, 1988. / Farming with ostriches became established as a new stock-farming activity in South Africa around 1863. Ostrich feathers were then the only commercial product of that activity and fifty years later still held fourth place on the list of exports from South Africa - after gold, diamonds and wool (Smit, 1963). However during the world depression of 1914 - 1945 the appeal of ostrich feathers vanished and the industry collapsed. Today commercial farming with domesticated ostriches (Struthi0 camelus var. domesticus), originating from a cross (Duerden, 1910; Smit, 1963, 1984) between the South African (Struthio camelus australis) and the North African ostriches (Struthio camelus camel us), is again a rapidly expanding activity in South Africa's Little Karoo. This is the only region in the world where farming with ostriches is still encountered at a commercial scale, and although relatively small in the general stock-farming scenario, it provides a livelihood for about 400 farmers who run some 150 000 ostriches. Feathers, together with ostrich leather and meat are all prominent export products that account for foreign exchange earnings of more than R30 million. In terms of monetary value the ostrich industry has grown by more than 300% over the past decade and by al most 100% in the 1ast 5 years. This high growth rate is primarily due to the steady development of the slaughter bird industry in which leather, meat and feathers account for more than 80% of the entire industry's turnover. Ostrich products, however, are primarily exclusive fashion products, of which more than 90% is exported. Because the world market is relatively small, expansion prospects for the industry are limited and sensitive to supply and demand. To ensure the industry's continued economic well-being, ostrich research pays particular attention to production techniques that will help to improve efficiency and result in better product quality and profitability. For the purpose of increased ostrich chick production, ostrich eggs are presently being incubated in large quantities (ca 200 000 eggs per annum). However, hatching success of ostrich eggs in incubators is considerably below that of natural nests, and Burger & Bertram (1981) suggested that it may be due to high humidities (63% relative humidity) commonly used in ostrich incubators. Investigations were undertaken to measure incubation temperatures and humidities during the complete course of 41 days of natural incubation in 6 ostrich nests. In addition, the water vapor conductance of the eggs was measured, as well as the incubation water loss which in other species averages 15% of the initial egg mass and has been proposed as an optimal condition for hatching success (Ar & Rahn, 1978; Rahn 1984). The natural incubation parameters measured during these experiments were adapted and applied to conditions of artificial incubation. This improved the realized hatchability from 50 to 75%. Furthermore the intensive production and finishing of slaughter birds on complete dry meal diets under feedlot conditions is a new development which contains exceptional possibilities for the industry (Swart & Kemm, 1985). Economically and biologically, efficient diet formulation has accordingly become essential for profitable slaughter bird production. The nutritional value of feed constituents for ostriches is, however, still unknown and without it effective least cost diet formulation and programming is not possible. Present growth and finishing diets for ostriches are based on energy values of the dietary components which have been derived from poultry (Blair, Daghir, Morimoto, Peter & Taylor, 1983; Du Preez, Duckitt & Paulse, 1986) and pig values (Kemm & Ras, 1981; NRC, 1973; IAFMM, 1985). This approach may, however, result in unreal estimation of the actual nutritional value of feed constituents for ostriches, so that quantification of their nutritional value has consequently become necessary. During 1985 a multi-disciplinary research programme on ostriches was initiated, the objective being to investigate the energy metabolism and the efficiency of energy utilization in growing farm ostriches. For the purpose of these experiments all ostrich chicks were incubated in an ostrich egg incubator, maintained at a dry bulb temperature of 36°C and a wet bulb temperature of 24,0 ± 1,0°C. These temperature settings were extrapolated from the natural incubation parameters measured in the six naturally incubated nests (Swart, Rahn & De Kock, 1987; Swart & Rahn, 1987). An important aspect of the studies on energy metabolism was to determine the extent to which plant fibre is digested in various segments of the gastrointestinal tract of growing ostriches and whether these birds utilize the end products of fibre digestion, namely volatile fatty acids such as acetic acid, efficiently. The possible use of metabolizable energy to evaluate feedstuffs for ostriches was an initial aim of this study. Subsequently the effect of crude fibre or energy concentration on the digestibility of gross energy, energy loss as methane, heat expenditure, and the effect on the efficiency of ME utilization were investigated. Finally accretion patterns and the partition of metabolizable energy during growth were studied in the young ostrich chick. The findings of the studies on incubation aspects (Section 1) are presented in Chapter 2 and 3 and that of the metabolism studies (Section 2) are presented in Chapters 4, 5, 6, 7 and 8 of this dissertation.

Thesis (PhD(Agric))--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The ostrich industry experiences high rates of embryonic mortalities during artificial incubation of eggs. Studies have been carried out to investigate factors influencing hatchability, as well as determining genotypic effects for commercial production. Eggs from the combination of South African Black (SAB) male ostriches crossed with Zimbabwean Blue (ZB) female ostriches had embryonic losses of 45.7%. The embryonic mortality of eggs produced by pure bred SAB or ZB breeding birds subjected to pure breeding was similar at around 33 - 34%, but embryonic mortality was improved in eggs produced by ZB males and SAB female crosses (27%). Female age had a significant effect on the proportion of chicks pipped, as well as on early and late the embryonic mortalities. Chicks from eggs stored for intermediate periods, i.e. 3, 4 and 6 days prior to being set, were more likely to pip than chicks from those eggs set directly after collection without storage. Embryonic mortality was increased in eggs that were set directly (32.0%) or subjected to longer than 6 days of storage (43.5%). Chicks that pipped in the correct position had a higher probability of successfully hatching than those pipping in the incorrect position. Transfer of eggs between setters (i.e. disturbance of eggs) during incubation reduced the number of ostrich chicks pipping in the correct position. Incubated ostrich eggs with intermediate levels of water loss, i.e. between 9.0 and 19% of fresh egg weight, were more likely to pip in the correct position than those with higher or lower levels of water loss. Such eggs were also less likely to sustain early, late or overall embryonic mortalities. To optimise hatching success it is important to understand embryonic development. After 2 days of incubation the blastoderm area in eggs from the SAB x ZB crosses (104.5 mm) was lower (P < 0.05) compared to the pure SAB (141.0 mm), pure ZB (161.7 mm) and ZB x SAB crosses (166.1 mm). For embryos incubated for 7 to 42 days, both embryonic and leg growth during the 42 days of incubation was similar and approximately linear, more or less doubling in size up to 35 days of incubation. The embryo eye size increased more rapidly than beak length and reached full size of approximately 16.2 mm by 28 days of incubation, whereas the beak length continued to increase until the chick hatched at 42 days. Incubation position, vertical or horizontal, did not affect any of the measurements of the developing embryo throughout the 42-day incubation period. Air cell volume at 29 day of incubation for infertile eggs (19.3%) was significantly (P < 0.05) higher when compared to dead-in-shell eggs (14.3%) and eggs that hatched successfully (13.8%). Air cell volume was largely independent of strain (SAB or ZB) and whether chicks were assisted to hatch or not. After 41 days of incubation there was a significantly greater (P < 0.05) air cell volume in eggs that hatched normally compared to dead-in-shell eggs (28.3% vs. 21.7%, respectively, suggesting that insufficient water loss contributed to reduced survival. This study provides an insight into the complexity of embryo development and all the factors playing a role in successful hatching of ostrich eggs. Data from a pair-mated ostrich flock were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21 (WL21) and 35 (WL35) days of incubation, and pipping time (PT). Single-trait estimates of heritability (h2) were high and significant (P < 0.05) at 0.46 for EWT, 0.34 for CWT, 0.34 for WL21, 0.27 for WL35 and 0.16 for pipping time. Genetic correlations with EWT amounted to -0.21 for WL21 and to -0.12 for WL35. Corresponding correlations of CWT with WL were highly significant (P < 0.05) at -0.43 and -0.54. Physical characteristics of the eggshell were found to affect water loss and hatchability. Estimates of genetic parameters of 14 146 ostrich eggs for eggshell traits showed that heritability was 0.42 for pore count (PC), 0.33 for shell thickness (ST) and 0.22 for permeability (PERM). PC was negatively correlated with average pore diameter (-0.58) and ST (-0.23), while PC was positively correlated with total pore area (0.58), WL21 (0.24) and WL35 (0.34). The correlations of PC with total pore area and PERM were high and significant. ST was negatively correlated to WL21 and WL35. Additive genetic parameters strongly indicate that it should be possible to alter evaporative water loss and eggshell quality of ostrich eggs through genetic selection. When assessed as a trait of the individual egg or chick, embryonic mortalities exhibited moderate levels of genetic variation both on the normal scale (h2 = 0.16 - 0.22) and the underlying liability scale (h2 = 0.21 - 0.31). Early embryonic survival and late embryonic survival was governed mostly by the same genes (rg = 0.78). Late embryonic survival was genetically correlated to WL35, at -0.22. It was concluded that embryonic survival could be improved by using husbandry measures, a knowledge of the stage when incubation mortalities occur, and by genetic selection, using an integrated approach. Findings from this study will help to understand the mechanisms involved in hatching from artificial incubation better to improve hatchability and also implement selective breeding programs. / AFRIKAANSE OPSOMMING: Die volstruisbedryf ondervind tans ‘n baie hoë voorkoms van embrionale mortaliteite tydens die kunsmatige uitbroei van eiers. Studies is uitgevoer om die faktore wat uitbroeibaarheid beinvloed te ondersoek en om genotipiese effekte te bepaal vir kommersiële produsente. Eiers van die kombinasie van Suid-Afrikaanse swart (SAB) mannetjie volstruise, met Zimbabwean blou (ZB) wyfies, het embrionale mortaliteite van 45.7% gehad. Embrionale mortaliteite van eiers gelê deur suiwer SAB of ZB volstruise was dieselfde op omtrent 33 - 34%, maar embrionale mortaliteite was laer vir eiers geproduseer deur SAB wyfies wat gekruis was met ZB mannetjies (27%). Wyfie ouderdom het ‘n betekenisvolle effek gehad op die proporsie van kuikens wat gepik het, asook die aantal vroeë- en laat embrionale mortaliteite. Kuikens vanuit eiers wat vir die periode 3, 4 dae en 6 dae voor pak in die broeikaste gestoor is, was meer geneig om te pik as kuikens vanaf eiers wat direk na kolleksie gepak is. Embrionale mortalitiete het verhoog vir eiers wat direk na kolleksie gepak was (32.0%) of vir eiers wat langer as 6 dae gestoor was (43.5%). Kuikens wat in die korrekte posisie pik het ‘n hoër kans op uitbroei gehad as kuikens wat in die verkeerde posisie gepik het. Die skuif van eiers tussen verskillende broeikaste (of enige steurnisse) gedurende die broeiproses het ‘n verlaging in die aantal kuikens wat in die korrekte posisie pik, gehad. Volstruiseiers met ‘n gemiddelde vogverlies van tussen 9.0 en 19% van die vars eier massa, was meer geneig om in die korrekte posisie te pik as eiers met laer of hoër vlakke van vogverlies. Sulke eiers was ook minder geneig tot vroeë, laat en totale embrionale mortaliteite. Vir optimale uitbroeisukses is dit belangrik om die ontwikkeling van die embrio te verstaan. Na 2 dae van broei was die blastoderm area in eiers van SAB x ZB kruisings (104.5 mm) kleiner (P < 0.05) as die blastoderm area van suiwer SAB (141.0 mm), suiwer ZB (161.7 mm) en ZB x SAB kruise (166.1 mm). Beide embrionale- en beengroei tydens die 42 dae broeiproses was dieselfde en nagenoeg lineêr, met ‘n verdubbeling in grootte tot en met 35 dae broei. Die embrio se oog vergroot vinniger as wat die snawel verleng en bereik reeds volle grootte van ongeveer 16.2 mm op 28 dae van broei, terwyl die snawel aanhou groei tot uitbroei van die kuiken op 42 dae. Nie die vertikale of horisontale broeiposisie het enige invloed op die metings van die ontwikkelende embrio tot op 42 dae gehad nie. Lugsakvolume vir geil eiers (19.3%) op 29 dae van broei was groter (P < 0.05) as beide die lugsakke van eiers wat dood-in-dop (14.3%) en eiers wat suksesvol uitgebroei het (13.8%). Die lugsakvolume was onafhanklik van beide genotype en of die kuiken met of sonder hulp uitgebroei het. Na 41 dae broei was lugsakvolume groter (P < 0.05) vir eiers wat uitgebroei het teenoor eiers wat dood-in-dop was (28.3% vs. 21.7%, onderskeidelik), wat impliseer dat onvoldoende vogverlies moontlik kan bydrae tot ‘n verlaging in embrionale oorlewing. Hierdie studie gee ‘n insig in die kompleksiteit van embrionale ontwikkeling en al die faktore wat ‘n rol speel in die suksesvolle uitbroei van volstruiseiers. Tydens die bepaling van genetiese parameters vir spesifieke uitbroei-eienskappe in volstruise, is data gebruik afkomend van ‘n teelkudde in ‘n enkelparing stelsel om genetiese waardes vir eiermassa (EWT), dagoud kuikenmassa (CWT), vogverlies tot 21 dae broei (WL21), vogverlies tot 35 dae broei (WL35) en piktyd (PT) gebruik. Enkeleienskap-beraming vir oorerflikheid (h2) was hoog en betekenisvol teen 0.46 vir EWT, 0.34 vir CWT, 0.34 vir WL21, 0.27 vir WL35 en 0.16 vir piktyd. Genetiese korrelasies met EWT was -0.21 vir WL21 en -0.12 vir WL35. Ooreenkomstig was korrelasies van CWT met WL21 en WL35 hoog (P < 0.05) met -0.43 en -0.54 onderskeidelik. Fisiese eienskappe van die eiers het beide vogverlies en uitbroeibaarheid beinvloed. Beramings van genetiese parameters vir 14 146 volstruiseiers se dopeienskappe het gewys dat oorerflikehid 0.42 was vir die aantal porieë (PC), 0.33 vir dopdikte (ST) en 0.22 vir deurlaatbaarheid (PERM). PC was negatief gekorreleerd met gemiddelde porieë deursnee (-0.58) en ST (-0.23), terwyl PC positief gekorreleerd was met totale porieë area (0.58), WL21 (0.24) en WL35 (0.34). Die korrelasie van PC met totale porieë area en deurlaatbaarheid was hoog en betekenisvol. ST was negatief gekorreleerd met WL21 en WL35. Additiewe genetiese parameters het sterk daarop gedui dat dit moontlik sou wees om vogverlies en eierkwaliteit (bv. dopkwaliteit en poreusiteit) van volstruiseiers te verander deur genetiese seleksie. Indien embrionale mortaliteit geevalueer word as ‘n kenmerk van die eier of kuiken, toon dit matige vlakke van genetiese variasie op beide die normale (h2 = 0.16 - 0.22) en die onderliggende skale (h2 = 0.21 - 0.31). Beide vroeë- en laat embrionale oorlewing word deur dieselfde stel gene beheer (rg = 0.78). Laat embrionale oorlewing was geneties gekorreleerd met WL35 teen -0.22. Die gevolgtrekking was dat embrionale oorlewing verbeter kan word deur verbeterde broeikamerpraktyke, kennis van op watter stadium van ontwikkelings embrionale mortaliteite plaasvind en deur genetiese seleksie. Bevindinge vanuit hierdie studies sal help om die meganismes betrokke by die kunsmatige uitbroei van volstruiskuikens beter te verstaan om sodoende uitbroeibaarheid te verbeter en ook suksesvolle seleksie programme te implementeer.

Em termos globais, existe urna tendência crescente na demanda por alimentos saudáveis e seguros. Visando esta demanda, a carne de avestruz é vista corno uma opção. A indústria sul-africana é a grande abastecedora da União Européia (UE) e o Brasil tenta disputar esse mercado, que é extremamente exigente em regras que garantam a produção de um alimento seguro, o que torna de vital importância um gerenciamento da qualidade em todas as fases de produção. Este estudo analisa o sistema agroindustrial da carne de avestruz, investigando os atributos de qualidade do produto divulgados por meio eletrônico de comunicação em dois países, África do Sul e Brasil, e comparando-os às necessidades de bem-estar do consumidor. Após pesquisa bibliográfica teórica, elaborou-se pesquisa documental, na qual os dados quantitativos do setor foram obtidos em fontes governamentais de cada país e os qualitativos em reportagens divulgadas em meio eletrônico e nos sites das empresas líderes de mercado em cada país, posteriormente submetidos à técnica de análise de conteúdo. Os resultados mostram que a produção sul africana atende às normas de gerenciamento de qualidade exigidas pelo bloco europeu, mas isso não foi suficientes para evitar reincidência de Influenza A em seu rebanho. Por outro lado, o brasileiro ainda não implementou o Plano Nacional de Controle de Resíduos (PNCR), sem o qual não consegue exportar, o que implica na obrigatoriedade de venda para o mercado interno, que possuí baixa demanda. Na comunicação adotada, ambos os países focam, principalmente, a dimensão biológica, seguido pelo bem-estar psicológico: o prazer de comer bem. / In global terms, there is a growing trend in the demand for healthy and safe food. Aiming this demand, ostrich meat is seen as an option. The South African industry is the major supplier of the European Union (EU) and Brazil tries to play this market, which has extremely demanding rules to ensure a safe food production, which makes a vital quality management in all stages of production. This study analyzes the agribusiness system of ostrich meat, investigating the quality attributes of the product disclosed by electronic means of communication in both countries, South Africa and Brazil, and comparing them to the needs of well-being of the consumer. After theoretical literature, was conducted archival research in which quantitative data were obtained from industry sources and government of each country in the qualitative reports electronically and posted on the websites of leading companies in each Country, then submitted to technique of content analysis. The results show that South African production meets quality management standards. required by the European bloc, but this was not sufficient to prevent recurrence of Influenza A in his flock. On the other hand, the Brazilian has yet to implement the National Plan for Waste Management (PNCR), without which it can not export, which implies the obligation to sell to the domestic market, which has low demand, Communication adopted in both countries focus mainly the biological dimension, followed by psychological well-being: the pleasure of eating well.

Thesis (MScVoedselwet)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Two experiments were conducted in order to manipulate the physical and chemical properties and shelf life of ostrich meat. Experiment 1: The effect of dietary fish oil rich in n-3 fatty acids on the organoleptic, fatty acid and physicochemical characteristics of ostrich meat. The diet of four ostrich groups (15 birds per group), approximately 3 months of age (ca. 41 kg live weight) grazing a predominantly oats pasture, was supplemented with a diet containing 6.7% fish oil. The birds received a supplement of either 0 (diet 1), 800 (diet 2), 1600 (diet 3) or 2400 g (diet 4) DM/day resulting in the consumption of 0 (diet 1), 14.5 (diet 2), 29 (diet 3) and 43.5 (diet 4) g fish oil per day. The ostriches were slaughtered at 10 months of age (ca. 70 kg live weight). An increase in the amount of fish oil consumed was found to have had statistically no significant effect on the sensory characteristics of the M. iliofibularis, although there was a tendency towards an increase in ‘fishiness’, for both aroma and flavour. However, increased concentrations of fish oil had a significant effect on the aroma and flavour of the abdominal fat pads. The muscle pHf and muscle lightness (L*) reflected a significant reduction with increased fish oil levels. The increased feed intake, on the other hand, had no effect on the chemical composition (moisture, protein, fat and ash content) of the meat. The fatty acid profile of both fat and meat was affected by the consumption of fish oil. The SFA concentration increased, while the PUFA concentration decreased, with an increase in feed intake. The MUFA concentration remained constant for all four groups. Experiment 2: The effect of dietary vitamin E and the type of packaging on the sensory quality, physicochemical composition and shelf life of ostrich meat. Two groups of ostriches (35 birds per group; ca. 3 months old) were fed diets containing either 40 mg/kg feed vitamin E (control) or 150 mg/kg feed Vitamin E for nine months. The birds were slaughtered at 12 months of age. The effect of different the levels of vitamin E and heat shrink treatment of vacuum packaging material on the shelf life of refrigerated (0°C) ostrich M. flexor cruris lateralis, was evaluated over 81 days. Vitamin E and heat shrink treatments were found to have had no significant effect on the sensory characteristics; off-meat aroma, sourness, juiciness and mealiness. Rancidity was found to be slightly more pronounced (although not statistical significant) in the vitamin E and heat shrink groups than in the feed control and vacuum-packed groups. A significant decrease in the organoleptic quality of the meat, over a 40 day shelf life period, was observed. The pH and muscle tenderness showed a significant reduction with increased storage time. The purge loss in the package increased over time with no change in muscle drip loss. The colour, conjugated dienoic acid and fatty acid content showed no significant changes over time or with regards to treatment. The total viable counts and coliform numbers in the muscle increased over time, with the coliforms being slightly suppressed by the inclusion of vitamin E in the diet. A microbiological safe shelf life of 40 days at 0°C was obtained. / AFRIKAANSE OPSOMMING: Twee eksperimente is uitgevoer om die fisiese en chemiese eienskappe, asook die rakleeftyd van volstruisvleis, te manipuleer. Eksperiment 1: Die effek van visolie, ryk aan n-3 vetsure, op die organoleptiese, vetsuur- en fisies-chemiese eienskappe van volstruisvleis. Die dieet van vier groepe volstruise (15 voëls per groep), ongeveer 3 maande oud (ca. 41 kg lewende massa) wat ‘n hawer weiding bewei het, is aangevul met ‘n byvoedingsmengsel wat 6.7% visolie bevat en in toenemende hoeveelhede vir die groepe volstruise gevoer is. Die voëls het ‘n aanvulling van 0 (dieet 1), 800 (dieet 2), 1600 (dieet 3) of 2400 g (dieet 4) DM/dag ontvang wat gelei het tot ‘n inname van 0 (dieet 1), 14.5 (dieet 2), 29 (dieet 3) en 43.5 (dieet 4) g visolie per dag. Die volstruise is op ‘n ouderdom van 10 maande geslag (ca. 70 kg lewende massa). ‘n Toename in die hoeveelheid visolie ingeneem, het geen statisties betekenisvolle effek op die sensoriese eienskappe van die M. ilifibularis gehad nie, alhoewel daar ‘n tendens was vir ‘n toename tot ‘n ‘visagtige’ aroma en smaak. ‘n Toename in die konsentrasie visolie het egter ‘n betekenisvolle effek op die ‘visagtige’ aroma en smaak van die abdominale vet neerslae gehad. Die spier pHf en spier ligtheid (L*) het ‘n betekenisvolle afname met toename in voer inname getoon. Die verhoogde olie inname het egter geen effek op die chemiese samestelling (vog-, proteïen-, vet- en asinhoud) van die vleis gehad nie. Die vetsuurprofiel van beide die abdominale vet neerslae en die vleis is deur die inname van visolie verander. Die versadigde vetsuurkonsentrasie het verhoog terwyl die poli-onversadigde vetsuurkonsentrasie verlaag het met ‘n toename in rantsoenvlakke. Die mono-onversadigde vetsuurkonsentrasie het egter konstant gebly vir al vier groepe. Eksperiment 2: Die effek van vitamien E en die tipe verpakking op die sensoriese kwaliteit, fisies-chemiese samestelling en rakleeftyd van volstruisvleis. Twee groepe volstruise (35 voëls per groep, ongeveer 3 maande oud) het voere oor ‘n tydperk van nege maande ontvang wat 40 mg vitamien E/kg voer (kontrole) of 150 mg vitamien E/kg voer bevat het. Die voëls is op 12 maande ouderdom geslag. Die effek van die verskillende vlakke van vitamien E en hitte-behandeling van die verpakkings materiaal op die rakleeftyd van verkoelde (0°C) volstruis M. flexor cruris lateralis, is oor 81 dae geëvalueer. Vitamien E en die hitte-behandeling het geen betekenisvolle effek op die organoleptiese eienskappe (af-vleis aroma, suurheid, sappigheid en melerigheid) gehad nie. Galsterigheid was ‘n bietjie meer gedefinieerd (anie-betekenisvol) in die vitamien E en hitte behandelde groepe as in die rantsoen kontrole en vakuum verpakte vleis. ‘n Betekenisvolle afname is waargeneem in die organoleptiese kwaliteit van die vleis oor ‘n 40 dae rakleeftyd periode. Die pH en taaiheid van die spier het betekenisvol afgeneem met ‘n toename in bergingsperiode. Die drup verlies tydens verpakking het ook oor tyd toegeneem, terwyl geen verandering in die analitiese drup verlies van die spier verkry is nie. Die kleur, gekonjugeerde dieensuur en vetsuursamestelling het geen verandering oor tyd of ten opsigte van behandeling getoon nie. Die Totale Lewendig Seltelling en coliforme het toegeneem oor tyd, terwyl die coliforme deur die byvoeging van vitamien E tot ‘n mate onderdruk is. ‘n Mikrobiologies veilige rakleeftyd van 40 dae is verkry.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2006. / The aim of this study is to determine the effect of crossbreeding Zimbabwean Blue (ZB) and South African Black (SAB) ostriches on the morphological, physical, chemical and sensory quality of the meat. However, it is also necessary to determine the reproductive performance of these genotypes to scientifically support decisions made in the ostrich industry. In relation to reproductive traits and body measurements influencing these traits, results from the study suggested that ZB birds are between 9 and 15% heavier than their SAB contemporaries. Regarding SAB females, egg production was 47% higher, levels of shell deaths were lower, percentage of eggs not incubated was lower (P<0.01) and 84% more (P<0.01) chicks were produced in a season compared to their ZB contemporaries. Mates of SAB males produced a higher (P≤0.05) percentage of eggs not incubated and higher shell death percentages than the mates of ZB males. It has to be conceded that ZB females had a lower reproduction than SAB females, limiting the application of this genotype as a dam line in crossbreeding systems. With regard to morphological properties, the pure Blue genotype in comparison to the pure Black genotype differed significantly (P≤0.05), with 16 kg for live weight, 8.3 kg for carcass weight and 3.5 kg for leg weight. However, when comparing carcass yields (expressed as %) there were no significant differences (P>0.05) between genotypes. The M. gastrocnemius, M. femorotibialis accessorius, M. iliotibialis cranialis, M iliotibialis lateralis, M. iliofibularis and M. iliofemoralis showed significant genotype differences (P≤0.05) for individual muscle weight. When comparing the physical meat quality characteristics between the pure Blue genotype and the pure Black genotype, 70% of the muscles were higher (P≤0.05) in pH24, 50% of the muscles were redder (P≤0.05) and significantly less (P≤0.05) saturated in colour, 67% of the muscles had a lower (P≤0.05) percentage drip loss and 50% of the muscles had a lower (P≤0.05) percentage cooking loss. No significant (P>0.05) genotype differences were observed regarding the sensory quality of the meat. Regarding chemical meat quality characteristics, the percentage of moisture was higher and the percentage of lipid was lower for eight of the ten muscle groups from the pure Blue genotype. No significant differences (P>0.05) were found between genotypes or between muscles regarding the percentage of protein present in the meat. The highest (P>0.05) content of soluble collagen, myoglobin and cholesterol was found in the Blue x Black genotype, whereas the lowest percentage of the latter constituents was found in the pure Blue genotype. For the pure Black genotype the concentration of saturated fatty acids in the meat was lower (P≤0.05), the concentrations of total unsaturated fatty acids and desirable fatty acids in the M. illiofibularis were the highest (P≤0.05), while the concentration of monounsaturated fatty acids was also higher (P≤0.05) in both muscles of this genotype compared to the other two genotypes. Regarding both fat depots, the pure Black genotype had a lower (P≤0.05) concentration of saturated fatty acids, a higher (P≤0.05) concentration of monounsaturated fatty acids and total unsaturated fatty acids and a higher (P≤0.05) polyunsaturated:saturated fatty acid ratio. The percentage of desirable fatty acids in the abdominal fat depot was significantly higher (P≤0.05) for the pure Black and the Blue x Black genotype. In conclusion, crossbreeding between SAB and ZB ostriches seems to be a viable option to produce larger birds with more meat, without negatively affecting the overall quality of the meat.

Made available in DSpace on 2016-06-02T19:51:24Z (GMT). No. of bitstreams: 1 DissPPB.pdf: 1061414 bytes, checksum: a5b3ff6d9a323a990c091374878b4aff (MD5) Previous issue date: 2006-10-26 / This study was performed in order to investigate the suplly chain of ostriches and to identify improviment factors for its managment to lead to the consolidation of the criation of ostriches in the brazilian agrobusiness. The work has pratical relevance since the national ostrich breeding has provobed great interest among the business men, livestockers and liberal workers a as new business opportunity for th brazilian agrobusiness. Besides that, the breeders already introduced in the sector are sceking for solutions to the existint problems. The theorical contextualization was approached through two main points: the evaluation of o new supply chain and its management. The research methodology used qas study multi-cases in wich ten breedeing localized in the state of São Paulo were investigated. The conclusion of the accomplished research have showed that the supply chain of ostriches in Brazil is in development so the companies and its partners need to search organization strategies for its viability a new alternative for the brazilian agrobusiness. / O objetivo desse trabalho foi estudar a cadeia de suprimento do avestruz e identificar fatores de aprimoramento para sua gestão como auxílio à consolidação da estrutiocultura no agronegócio brasileiro. O trabalho tem relevância prática pois a criação racional de avestruzes tem despertado enorme interesse entre empresários, pecuaristas e profissionais liberais, por ser uma nova oportunidade de negócio para a agropecuária brasileira. Além disso os criadores já inseridos no setor mostram-se em busca de soluções dos problemas existentes. A contextualização teórica é abordada por meio de dois enfoques principais: avaliação de uma nova cadeia de suprimento e a sua gestão. A metodologia de pesquisa utilizada foi o estudo multi-casos, tendo sido investigados dez criatórios localizados no Estado de São Paulo. A conclusão da pesquisa realizada revelou que a cadeia de suprimento do avestruz no Brasil está em formação necessitando que as empresas busquem com seus parceiros estratégias organizacionais para a sua viabilidade como uma nova alternativa para o agronegócio brasileiro.