A dissertation submitted to the faculty of science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science Johannesburg, August 2017 / MT 2018

Thesis (PhD)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Although small, the South African ostrich industry contributes 60% to the total world production of slaughter ostriches. Ostrich leather contributes more than 50% of the R2.1 billion turnover of this industry. This study is the first structured investigation into the characteristics of ostrich leather focussing on factors such as age, nutrition, slaughter weight, and genetics, and the influence thereof on intrinsic leather traits. Large variation in terms of skin quality was found between producers, month of the year and production years. The effect of age suggested that leather thickness and tensile strength increased with age while the number of nodules declined by 2.8 for every month increase in slaughter age. Slit tear strength and tensile strength increased with heavier slaughter weights. Older ostriches had higher values for slit tear strength and skin thickness. Nodule diameter increased at a rate of 0.08mm per month increase in age. Nodules with an average diameter of more than 4.0mm were only obtained in the combination of old heavy birds, while nodule diameter of the other age-weight combinations ranged between 3.3mm and 3.5mm. Subjective assessment of nodule traits by participants with or without prior knowledge of age suggested that slaughter age accounted for 46% of the variation in estimated slaughter age. Nodule acceptability scores generally increased with an increase in slaughter age. Moderately acceptable scores were found in skins from birds 11 months and older. The effect of energy and protein concentrations of ostrich diets suggested that raw skin areas were 19.4% and 21.8% larger at slaughter for birds receiving a diet containing 10.5 MJ/ME and 12.0 MJ ME/kg DM respectively, compared to that of birds receiving a 9.0 MJ ME/kg DM diet. Leather thickness taken parallel to the spine was increased by 13% when birds were fed the higher energy diet. Dietary protein concentrations failed to influence skin weight, skin area or any physical leather properties. The genetic variation in nodule size measured at different sampling sites on the skin suggested that nodule size increased chronologically with age at the neck, back, upper leg, and flank and butt areas. Estimates of h² for nodule size ranged from 0.09 ± 0.07 on the flank region to 0.24 ± 0.10 on the upper leg region. Preliminary results seem to suggest that nodule size on different locations of the skin is not necessarily the same genetic trait. It was concluded that measurements at any specific site is unlikely to predict measurements at other sites with a high degree of accuracy due to the large variation that exists between measurement sites. This dissertation provides an insight into the complexity of ostrich leather quality, and the interaction of leather traits, such as nodule size and shape, leather thickness and tensile strength, that determine ostrich leather quality. / AFRIKAANSE OPSOMMING: Alhoewel klein, produseer die Suid-Afrikaanse volstruisbedryf 60% van die totale wêreldproduksie van slagvolstruise. Volstruisleer is verantwoordelik vir meer as 50% van die R 2.1 biljoen omset van die bedryf. Hierdie studie is die eerste gestruktureerde ondersoek na die intrinsieke eienskappe van volstruisleer en die invloed van ouderdom, voeding, slagmassa en genetika op hierdie eienskappe. Groot variasie t.o.v. leerkwaliteit is waargeneem tussen produsente, maande van die jaar en produksiejare. Die effek van ouderdom toon dat leerdikte en treksterkte verhoog het met toename in ouderdom, terwyl die aantal knoppies afneem met 2.8 vir elke maand toename in slagouderdom. Skeur- en treksterkte het verhoog met ʼn swaarder slagmassa (64kg vs. 99kg). Hoër waardes vir skeursterkte en veldikte is vir ouer voëls (384 dae vs. 234 dae ouderdom) verkry. Knoppie deursnit het teen ʼn tempo van 0.08mm per maand toename in ouderdom verhoog. Knoppies met ʼn gemiddelde deursit van groter as 4.0mm is slegs waargeneem in swaar-ou voëls, terwyl die knoppie deursnit van die ander massa-ouderdom kombinasies tussen 3.3mm en 3.5mm gewissel het. Die subjektiewe waarneming van 28 respondente, ingelig of oningelig oor die betrokke slagouderdom, dui daarop dat die werklike slagouderdom verantwoordelik is vir 46% van die variasie in geskatte slagouderdom. Die puntetoekenning vir knoppie-aanvaarbaarheid het verhoog met ‘n toename in slagouderdom. Aanvaarbare puntetoekenning vir knoppie-ontwikkeling is verkry vir voëls vanaf 11 maande en ouer. Die effek van energie- en proteïenkonsentrasies in volstruisdiëte toon dat die rouveloppervlakte onderskeidelik 19.4% en 21.8 % groter was met slagting vir voëls wat onderskeidelik ‘n 10.5 MJ/ME en 12.0 MJ ME/kg DM diëte gevoer is, in vergelyking met voëls wat ‘n 9.0 MJ ME/kg DM dieet ontvang het. Leerdikte, geneem parallel met die ruggraat, het met 13% toegeneem wanneer die hoër energie dieet gevoer is. Dieetproteïen konsentrasies het geen invloed op velmassa, veloppervlakte of enige fisiese leerkwaliteitseienskappe gehad nie. Die genetiese variasie in knoppiegrootte geneem op verskillende lokaliteite op die vel toon ʼn chronologiese toename met ouderdom in die nek-, rug-, boud-, sy- en stuitjie gebiede. Beraamde h² vir knoppiegrootte wissel vanaf 0.09±0.07 op die sye tot 0.24±0.10 op die boudgedeelte. Voorlopige resultate dui aan dat knoppiegrootte op verskillende lokaliteite nie noodwendig dieselfde genetiese basis het nie. Die gebruik van een lokaliteit vir die voorspelling van die eienskappe van ʼn ander, blyk nie sinvol te wees nie a.g.v. die groot variasie wat tussen verskillende lokaliteite bestaan. Hierdie studie verskaf insig oor die kompleksiteit van volstruisleerkwaliteit en die interaksie van leereienskappe soos knoppiegrootte en –deursnit, veldikte en treksterkte, in die bepaling van leerkwaliteit.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Although transport and lairage of ostriches are accepted causes of production losses, these losses have not yet been quantified. Transport and lairage regulations focus on the wellbeing of the birds and, by default reduce some losses. This thesis investigated weight losses and meat quality of ostriches as a result of transport density, lairage duration and lairage feed availability (ad libitum). All birds were reared on the same farm and loaded and transported together. They were randomly divided into their respective groups on loading for the transport trial, and on offloading for the lairage trial. Bird grouping was according to density for the transport trial (4 groups, H1, H2: 0.56m2/bird and L1, L2: 0.96m2/bird) and according to time spent in lairage and feed availability for the lairage trial (n=30 birds/group; L0hr and L24hr; n=15 birds/group L48hr and L48hr ad libitum feed). Behavioural observations of the ostriches showed a tendency of the ostriches to lean against objects and to orientate towards forces exerted on it to help keep its balance. Reactions to sound fluctuations were noted, with birds reacting towards changes in sound volume during transport and lairage. Timepoint numbers were allocated for each time the birds were weighed during the trial. Time points 1, 2, 3, 4 and 5 were allocated to loading, arrival, 19 hr in lairage, 31 hr in lairage and 39 hr in lairage respectively for Trial 2. Results showed no differences (P > 0.05) in live weights or meat quality parameters between Groups H1, H2, L1 and L2 during transport. Differences (P < 0.05) were found in cumulative weight losses between L0hr and the rest of the groups for time point 1. Differences between L48hr and L48hr ad libitum were found for time point 4 for cumulative weight loss. L48hr also differed significantly between the other lairage duration groups for dressing percentages as a function of loading weight. Ad libitum feed availability had a significant effect on live body weight changes but not the meat quality parameters for the groups held for 48hr in lairage. The number of birds having bruises (≈50% per group) was similar between groups and lairage had no influence on bruising. Results seem to indicate that the evaluated transport densities had no effect on the weight loss or meat quality of ostriches. However, the results indicate that the lairage period should be studied further with specific reference to weight losses during lairage. Meat quality was unaffected by the lairage parameters reported in this thesis. / AFRIKAASE OPSOMMING: Hoewel vervoer en voorslag hou (“lairage”) aanvaar word as die oorsake van produksieverliese, is hierdie aspekte nog nie gekwantifiseer nie. Regulasies in terme van vervoer en voorslag hou fokus op die welstand van die voëls en gevolglik verminder sommige verliese met hierdie faktore. Konflik tussen boere en sekondêre produsente (abattoirs en verwerkers) oor die kostes verbonde aan hierdie gewigsverliese, is in wese ‘n oorsaak van oorbruggingsfases (vervoer). Daarom is die voorslag hou-parameters van tyd, voerbeskikbaarheid en laai digtheid ondersoek. Twee proewe is geloods; een vir vervoer en een vir voorslag aanhou. Voëls is voor hulle op vragmotors gelaai is, geweeg en op spesifieke tye daarna geweeg. Diere van die laaidigtheidsproef is ingedeel in vier groepe (H1, H2: 0.56m2/voel en L1, L2: 0.96m2/voel). Met aflaai is die eerste toets groep geslag terwyl die tweede toets groep ingedeel is volgens die tyd gespandeer en voer beskikbaarheid in voorslag aanhou (n=30 voëls/groep - Groepe L0u, L24u; n=15 voëls/groep - L48u en L48u ad libitum gevoer). Gedrag van voëls is aangeteken tydens vervoer. Finale gewig was slagpale gewig en elke tyd periode waar die voëls geweeg is, is aangeteken as ‘n tydpunt. Vleiskwaliteit analises is gedoen op die linker boud se fan filet. ‘n Standaard rak leeftyd toets is ook gedoen om kwaliteit parameters te toets oor tyd. pH is gekatorigiseer volgens groepe om moontlike verskille te beklemtoon. Gedrag is opgeteken volgens die oriëntasie en steunings gewoontes van die volstruise gedurende vervoer. Voëls probeer hulle balans te hou deur op voorwerpe en op mekaar te leun, asook om hul liggaam oriëntasie te gebruik. Reaksies tot klank veranderinge is ook opgemerk tydens vervoer en voorslag aanhou. Resultate toon geen betekenisvolle verkille tussen digtheid groepe H1, H2, L1 en L2 nie. Geen gewigsverskille is gevind tussen vervoerdigtheid groepe nie. Vleiskwaliteit-parameters is ook ondersoek en geen verskille is gevind tussen groepe nie. Resultate toon wel betekenisvolle verskille in gewigsverlies-persentasie tussen groepe vir tyd in voorslag aanhou. Groepe L48u en L48u ad libitum, het onder andere betekenisvol verskille getoon vir tydpunt 4. Betekenisvolle verskille in uitslagpersentasie as funksie van begin-gewig tussen 48 uur en die res van die groepe is ook gevind. Verdere vleiskwaliteit-parameters (drupverlies, pH, ens.) tussen groepe het geen betekenisvolle verskille getoon nie. Resultate dui aan dat voer beskikbaarheid het ‘n invloed op gewigsverskille in voorslag aanhou. Regulasies vir voorslag hou, vervoer en welstand van volstruise sal moontlik verder ondersoek moet word met spesiale klem op die nut van voorslag aanhou en die se invloed op gewigsverlies. Vleiskwaliteits-parameters is nie beïnvloed deur die aspekte ondersoek nie.

Bactérias da microbiota entérica de avestruzes foram isoladas e fermentadas (produto experimental denominado de ECOS). Em seguida, foram utilizadas na exclusão competitiva de Salmonella Typhimurium em pintinhos (\"Gallus gallus\") e em avestruzes recém nascidas (\"Struthio camelus\"). Os pintinhos e as avestruzes foram desafiados por via oral com a concentração de 1x104 UFC/ ave e 1x105 UFC/ ave, respectivamente. O ECOS reduziu significativamente a excreção de Salmonella Typhimurium em pintinhos e avestruzes recém nascidos infectados experimentalmente. O ECOS também reduziu significativamente os casos de enterites associadas à mortalidade em avestruzes, em testes de campo. Outros aspectos observados em avestruzes tratados a campo foram a redução do tempo de absorção do saco vitelínico e o aumento do ganho de peso. O ECOS mostrou ser uma importante ferramenta na melhoraria dos índices zootécnicos em estrutiocultura. / Bacterias of ostrich enteric microbiota were isolated and fermented (product called ECOS). Afterwards, they were used into a competitive exclusion of Salmonella Typhimurium in chicks (\"Gallus gallus\") and in ostriches chicks (\"Struthio camelus\"). The chicks and the ostriches were challenged by oral administration by 1x104 UFC/ chick e 1x105 UFC/ chick, respectively. ECOS reduced the excretion of Salmonella Typhimurium in chicks and ostriches chicks experimentaly infected. ECOS reduced, as well, cases of enteric diseases associated to ostrich mortality, in field tests. Another aspect observed in field treated ostrich, was the reduction of yolk sac absorption time and the increase of weight gain. ECOS showed to be an important tool to increase the zootecnical standards in ostrich farming.

Bactérias da microbiota entérica de avestruzes foram isoladas e fermentadas (produto experimental denominado de ECOS). Em seguida, foram utilizadas na exclusão competitiva de Salmonella Typhimurium em pintinhos (\"Gallus gallus\") e em avestruzes recém nascidas (\"Struthio camelus\"). Os pintinhos e as avestruzes foram desafiados por via oral com a concentração de 1x104 UFC/ ave e 1x105 UFC/ ave, respectivamente. O ECOS reduziu significativamente a excreção de Salmonella Typhimurium em pintinhos e avestruzes recém nascidos infectados experimentalmente. O ECOS também reduziu significativamente os casos de enterites associadas à mortalidade em avestruzes, em testes de campo. Outros aspectos observados em avestruzes tratados a campo foram a redução do tempo de absorção do saco vitelínico e o aumento do ganho de peso. O ECOS mostrou ser uma importante ferramenta na melhoraria dos índices zootécnicos em estrutiocultura. / Bacterias of ostrich enteric microbiota were isolated and fermented (product called ECOS). Afterwards, they were used into a competitive exclusion of Salmonella Typhimurium in chicks (\"Gallus gallus\") and in ostriches chicks (\"Struthio camelus\"). The chicks and the ostriches were challenged by oral administration by 1x104 UFC/ chick e 1x105 UFC/ chick, respectively. ECOS reduced the excretion of Salmonella Typhimurium in chicks and ostriches chicks experimentaly infected. ECOS reduced, as well, cases of enteric diseases associated to ostrich mortality, in field tests. Another aspect observed in field treated ostrich, was the reduction of yolk sac absorption time and the increase of weight gain. ECOS showed to be an important tool to increase the zootecnical standards in ostrich farming.

Orientador: Angelo Berchieri Junior / Banca: Karin Werther / Banca: Antonio José Piantino Ferreira / Resumo: As criações de avestruzes vêm se desenvolvendo no Brasil e em outros países. De acordo com a literatura, Salmonella sp está envolvida na mortalidade de filhotes de avestruzes, sendo também importantes causadoras de toxinfecção alimentar em seres humanos. Apesar disso, existem poucos estudos envolvendo a pesquisa de Salmonella sp nesta espécie. Desse modo, elaborou-se o presente trabalho com o objetivo de pesquisar Salmonella sp em avestruzes de uma propriedade da região sudeste do Brasil. Para isso, foram realizados exames bacteriológicos, em 80 amostras de fezes de avestruzes (colhidas nas varias fases da criação), 90 ovos não eclodidos, 30 amostras de ração e em 30 amostras de fezes de roedores presentes na propriedade. Em seguida, investigou-se Salmonella sp em fezes, conteúdo cecal, fígado, baço e carcaça de 90 avestruzes abatidos. Aliado a isso, colheu-se o soro sanguíneo destes animais para a realização do "teste da Pulorose". Os exames microbiológicos demonstraram ausência de Salmonella sp em amostras de fezes de roedores e em fezes, ovos, conteúdo cecal, fígado, baço e carcaça dos avestruzes analisados. Por outro lado, Salmonella enterica subespécie enterica 4, 12: i:- foi isolada de uma amostra de ração e Salmonella Javiana de outras duas. O teste sorológico foi negativo nas 90 amostras. O sistema de criação, o bom manejo sanitário adotado na propriedade e a adoção dos programas de Boas Práticas de Fabricação (BPF) e Análise de Perigos e Pontos Críticos de Controle (APPCC) no abatedouro contribuíram para a ausência de Salmonella sp nas amostras examinadas. / Abstract: In recent years, the ostrich farming has expanded considerably in Brazil and all over the world. According to literature, Salmonella sp causes mortality in ostrich chicks, being also responsible for human food borne diseases. Even though, little research has focused on Salmonella in ostriches. This study was elaborated with the purpose to search for Salmonella sp in ostriches of a farm located on Brazilian southwest region. By conventional microbiological method, Salmonella sp was researched in 80 samples of ostrich's droppings, 90 eggs, 30 samples of feed and 30 samples of droppings from resident rodent population. In sequence, this bacterium was searched in droppings, caecal content, spleen, liver and carcass from 90 slaughtered ostriches. Also, blood serum of those animals were harvested and submitted to test for Pullorum Disease (Rapid Serum Blood Agglutination Test). No Salmonella sp was detected in eggs, caecal content, liver, spleen, carcass and droppings from ostriches, nor in droppings from rodents. On the other hand, Salmonella Javiana was isolated from two samples of feed and Salmonella enterica enterica 4, 12: i:- from another one. The serologic test was negative for all samples. The management of ostrich farming, the good sanitary management adopted on farm and the application of Hazard Analysis and Critical Control Point (HACCP) principles and Good Manufacturing Practices (GMP) during the slaughter process contributed for absence of Salmonella sp on samples assayed. / Mestre

Made available in DSpace on 2014-06-11T19:27:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-18Bitstream added on 2014-06-13T18:56:55Z : No. of bitstreams: 1 freitasneto_oc_me_jabo.pdf: 351713 bytes, checksum: 82c0d6bd573bc832444c3d0fe2427852 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As criações de avestruzes vêm se desenvolvendo no Brasil e em outros países. De acordo com a literatura, Salmonella sp está envolvida na mortalidade de filhotes de avestruzes, sendo também importantes causadoras de toxinfecção alimentar em seres humanos. Apesar disso, existem poucos estudos envolvendo a pesquisa de Salmonella sp nesta espécie. Desse modo, elaborou-se o presente trabalho com o objetivo de pesquisar Salmonella sp em avestruzes de uma propriedade da região sudeste do Brasil. Para isso, foram realizados exames bacteriológicos, em 80 amostras de fezes de avestruzes (colhidas nas varias fases da criação), 90 ovos não eclodidos, 30 amostras de ração e em 30 amostras de fezes de roedores presentes na propriedade. Em seguida, investigou-se Salmonella sp em fezes, conteúdo cecal, fígado, baço e carcaça de 90 avestruzes abatidos. Aliado a isso, colheu-se o soro sanguíneo destes animais para a realização do “teste da Pulorose”. Os exames microbiológicos demonstraram ausência de Salmonella sp em amostras de fezes de roedores e em fezes, ovos, conteúdo cecal, fígado, baço e carcaça dos avestruzes analisados. Por outro lado, Salmonella enterica subespécie enterica 4, 12: i:- foi isolada de uma amostra de ração e Salmonella Javiana de outras duas. O teste sorológico foi negativo nas 90 amostras. O sistema de criação, o bom manejo sanitário adotado na propriedade e a adoção dos programas de Boas Práticas de Fabricação (BPF) e Análise de Perigos e Pontos Críticos de Controle (APPCC) no abatedouro contribuíram para a ausência de Salmonella sp nas amostras examinadas. / In recent years, the ostrich farming has expanded considerably in Brazil and all over the world. According to literature, Salmonella sp causes mortality in ostrich chicks, being also responsible for human food borne diseases. Even though, little research has focused on Salmonella in ostriches. This study was elaborated with the purpose to search for Salmonella sp in ostriches of a farm located on Brazilian southwest region. By conventional microbiological method, Salmonella sp was researched in 80 samples of ostrich’s droppings, 90 eggs, 30 samples of feed and 30 samples of droppings from resident rodent population. In sequence, this bacterium was searched in droppings, caecal content, spleen, liver and carcass from 90 slaughtered ostriches. Also, blood serum of those animals were harvested and submitted to test for Pullorum Disease (Rapid Serum Blood Agglutination Test). No Salmonella sp was detected in eggs, caecal content, liver, spleen, carcass and droppings from ostriches, nor in droppings from rodents. On the other hand, Salmonella Javiana was isolated from two samples of feed and Salmonella enterica enterica 4, 12: i:- from another one. The serologic test was negative for all samples. The management of ostrich farming, the good sanitary management adopted on farm and the application of Hazard Analysis and Critical Control Point (HACCP) principles and Good Manufacturing Practices (GMP) during the slaughter process contributed for absence of Salmonella sp on samples assayed.

Made available in DSpace on 2014-06-11T19:29:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-10-06Bitstream added on 2014-06-13T18:39:11Z : No. of bitstreams: 1 contente_apa_me_botfmvz.pdf: 140898 bytes, checksum: c165ef6056310c9a82a051e2dd8285bc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A toxoplasmose é uma zoonose cosmopolita causada pelo protozoário Toxoplasma gondii, podendo acometer mamíferos e aves. O presente estudo teve como objetivo estimar a prevalência de anticorpos anti-Toxoplasma gondii em avestruzes de criatórios comerciais do Estado de São Paulo, como forma de auxiliar no conhecimento do comportamento e importância do parasito nesta espécie animal. Foram colhidas 195 amostras de soro de avestruzes (Struthio camelus), provenientes de Sorocaba, Campinas, São Carlos, Araçatuba, São Paulo, Vale do Ribeira, Botucatu e São José do Rio Preto, estado de São Paulo. As amostras foram analisadas pela Técnica de Aglutinação Direta Modificada (MAT), para a pesquisa de anticorpos anti-Toxoplasma gondii. Os exames sorológicos revelaram 14,36% de animais sororreagentes ao T. gondii. A titulação mínima considerada foi a diluição maior ou igual a 1:16, e a maior diluição encontrada foi 1:16384. Não foi constatada diferença significativa entre os sexos. Apenas duas regiões (São Paulo e São José do Rio Preto) não apresentaram animais sororreagentes. Esses resultados salientam a importância de um estudo mais aprofundado sobre a infecção em avestruzes, e também sobre práticas de manejo que venham a minimizar os riscos de transmissão da toxoplasmose para essas aves e, por conseqüência, para o consumidor final. / Toxoplasmosis is a widespread zoonosis caused by Toxoplasma gondii, a protozoan that may infect mammals and birds. The aim of the present study was to measure the prevalence of T. gondii in ostriches (Struthio camelus) from commercial farms of São Paulo State, as a way to help in the knowledge and importance of the parasite in this animal specie. 195 serum samples were collected from ostriches proceeding from Sorocaba, Campinas, São Carlos, Araçatuba, São Paulo, Vale do Ribeira, Botucatu e São José do Rio Preto, São Paulo State. These samples were tested using the Modified Agglutination Test (MAT) to the investigation of Toxoplasma gondii antibodies. This search detected 14,36% seropositive animals to Toxoplasma gondii. The minimum titration considered was the larger dilution or same to the 1:16, and the higher dilution was 1:16384. It was not found any significant statistical difference between males and females. In only two regions (São Paulo and São José do Rio Preto), there was no seropositive animals. Those results point out the importance of a study more deepened about this infection in ostriches, and about management practices that could minimize the toxoplasmosis transmission risks to these birds and, by consequence, to the final consumer.

Orientador: Paulo Francisco Domingues / Banca: Roberta Lemos Freire / Banca: Germano Biondo / Resumo: A toxoplasmose é uma zoonose cosmopolita causada pelo protozoário Toxoplasma gondii, podendo acometer mamíferos e aves. O presente estudo teve como objetivo estimar a prevalência de anticorpos anti-Toxoplasma gondii em avestruzes de criatórios comerciais do Estado de São Paulo, como forma de auxiliar no conhecimento do comportamento e importância do parasito nesta espécie animal. Foram colhidas 195 amostras de soro de avestruzes (Struthio camelus), provenientes de Sorocaba, Campinas, São Carlos, Araçatuba, São Paulo, Vale do Ribeira, Botucatu e São José do Rio Preto, estado de São Paulo. As amostras foram analisadas pela Técnica de Aglutinação Direta Modificada (MAT), para a pesquisa de anticorpos anti-Toxoplasma gondii. Os exames sorológicos revelaram 14,36% de animais sororreagentes ao T. gondii. A titulação mínima considerada foi a diluição maior ou igual a 1:16, e a maior diluição encontrada foi 1:16384. Não foi constatada diferença significativa entre os sexos. Apenas duas regiões (São Paulo e São José do Rio Preto) não apresentaram animais sororreagentes. Esses resultados salientam a importância de um estudo mais aprofundado sobre a infecção em avestruzes, e também sobre práticas de manejo que venham a minimizar os riscos de transmissão da toxoplasmose para essas aves e, por conseqüência, para o consumidor final. / Abstract: Toxoplasmosis is a widespread zoonosis caused by Toxoplasma gondii, a protozoan that may infect mammals and birds. The aim of the present study was to measure the prevalence of T. gondii in ostriches (Struthio camelus) from commercial farms of São Paulo State, as a way to help in the knowledge and importance of the parasite in this animal specie. 195 serum samples were collected from ostriches proceeding from Sorocaba, Campinas, São Carlos, Araçatuba, São Paulo, Vale do Ribeira, Botucatu e São José do Rio Preto, São Paulo State. These samples were tested using the Modified Agglutination Test (MAT) to the investigation of Toxoplasma gondii antibodies. This search detected 14,36% seropositive animals to Toxoplasma gondii. The minimum titration considered was the larger dilution or same to the 1:16, and the higher dilution was 1:16384. It was not found any significant statistical difference between males and females. In only two regions (São Paulo and São José do Rio Preto), there was no seropositive animals. Those results point out the importance of a study more deepened about this infection in ostriches, and about management practices that could minimize the toxoplasmosis transmission risks to these birds and, by consequence, to the final consumer. / Mestre

Ostriches are an important commercial species in South Africa and are becoming increasingly so in other parts of the world. Fertility and hatchability of artificially incubated ostrich eggs, however, is generally regarded as low compared to other poultry species and to ostriches in the wild. Investigation into specific farming practices at present indicated scope for an overall improvement in productivity through a sound breeding strategy. This thesis investigated factors that affect egg production, fertility, and hatchability of artificially incubated eggs in the Little Karoo region of South Africa. Specific breeding pair combinations accounted for the major variations in egg weight, hatchability, chick production and offspring weight at slaughter age. An appreciable proportion of variation in reproductive traits was attributable to the repeatable nature of breeding pair performance from year to year, even from first breeding attempts, suggesting that selection of good breeding stock can be made from an early age. Artificially incubated eggs showed improved hatchability when eggs were collected two to three hours after lay rather than the following morning. Storing position of eggs did not significantly effect hatchability when eggs were stored for a maximum of one week. The critical zero temperature for ostrich eggs, below which no embryonical development takes place, was found to be ± 25°C and cooling eggs to temperatures below 20°C for complete cessation of embryonic development during storage resulted in better hatchabilities compared to eggs stored at 25°C room temperature. Hatchability decreased when incubator temperatures were raised from 36 to 37.3°C. Large temperature fluctuations and gradients, which encompass detrimental temperatures, persist within forced draught wooden incubators of the type most commonly in use in the Little Karoo region. The highest temperatures occurred at the top of these incubators and will consequently have a negative impact on hatchability. The ontogeny of ostrich egg metabolism showed an exponential increase during the first 70% of incubation followed by a decline to 75% of the peak value between days 31 and 38 of incubation. From peak levels of embryonic development it was calculated that single stage incubators needs an airflow of 54.4 1/egg.hour to maintain oxygen levels just below 21% and carbon dioxide levels below 0.5%. Lower embryonic mortalities were observed when eggs were turned twenty-four times/day in an electronic incubator compared to hand turning twice a day. Eggs rotated through increasing angles between 60 and 90° resulted in a linear improvement in hatchability. In incubators where turning angles were fixed at 60°, lower hatchabilities were overcome by incubating eggs for 2 - 3 weeks in a horizontal position before placing them vertically. No specific farming practice could be singled out as the main cause of low fertility or hatchability but rather a combination of certain practices applied wrongly.