O presente trabalho avaliou os níveis séricos de testosterona total e de corticosterona em avestruzes machos e os correlacionou com o comportamento (grau de agressividade e presença ou não de kantling) e as características sexuais secundárias (tamanho de bolsa fálica, tipo e intensidade da coloração de canela e bico) dentro e fora do período reprodutivo destas aves. Além disso, foi descrito o ciclo circadiano dos hormônios testosterona e corticosterona de dois avestruzes machos em reprodução. A técnica utilizada para a dosagem hormonal foi a radioimunoensaio, sendo validada a técnica para a espécie em questão. Durante o período de observações e coleta das amostras de soro das aves avaliadas ao longo da estação reprodutiva foi observada diferença estatística (p<0,05) para as variáveis coloração e níveis de testosterona sérica para os animais em reprodução quando comparados com os animais fora do período reprodutivo (3,96 + 0,11 vs. 3,06 + 0,36, 173,48 + 12,26 vs. 63,92 + 14,75ng/ml, respectivamente). Verificaram-se correlações entre grau de agressividade e tamanho de bolsa fálica dentro (r=0,18; p=0,04) e fora (r=0,38; p=0,03) da estação reprodutiva, coloração de bico e canela e tamanho de bolsa fálica em reprodução (r=0,67; p<0,0001) e fora da reprodução (r=0,68; p<0,0001), níveis séricos de testosterona total e tamanho de bolsa fálica em reprodução (r=0,43; p<0,0001) e fora da reprodução (r=0,51; p=0,0028), níveis séricos de testosterona total e coloração de canela e bico em reprodução (r=0,53; p<0,0001) e fora da reprodução (r=0,72; p<0,0001). Foi também observada correlação positiva para a variável kantling e grau de agressividade no período reprodutivo (r=0,29; p<0,0008), níveis séricos de testosterona total e de corticosterona no período reprodutivo (r=0,43; p<0,0015) e entre kantling e coloração de canela e bico no período não reprodutivo (r=0,36; p<0,04) para as aves estudadas. Na segunda parte do experimento 30 avestruzes machos foram classificados em três níveis (nível 1 - aves com maior bolsa fálica, maior grau de agressividade e coloração; nível 2 - aves com tamanho de bolsa fálica mediano, grau de agressividade e de coloração mediano; nível 3 - aves com tamanho de bolsa fálica menor, menor grau de agressividade e coloração menos intensa) e a produção total de ovos, ovos férteis, ovos inférteis, ovos contaminados, ovos com morte embrionária e total de filhotes nascidos vivos de cada grupo foi analisado estatisticamente, observando-se que as aves pertencentes ao nível 1 obtiveram os melhores índices para as variáveis de produção total de ovos, ovos férteis e total de filhotes nascidos vivos em relação as aves pertencentes ao nível 3. Os resultados do presente experimento descrevem a existência da relação entre os níveis séricos de testosterona e as características sexuais de avestruzes, tais como tamanho de bolsa fálica e grau de coloração, além de descrever a existência de uma relação entre as características sexuais reprodutivas e comportamentais de avestruzes machos e alguns dos seus índices de produção. / The present study evaluated the levels of total serum testosterone and corticosterone in male ostriches and to correlate those values with the behavioral (degree of aggressiveness and presence or not of kantling) and the secondary sexual characteristics (cloacal size, type and intensity of the color of the peak and cinnamon) during the reproductive and non-reproductive seasons of these birds. Moreover, the circadian cycle of the hormones testosterone and corticosterone of two male ostriches in reproduction was described. The technique used for the hormonal assay was the radioimmunoassay, which was validated for the specie. During the period of observations and serum samples collection, differences (p<0,05) were found on color and serum levels of testosterone when comparing the reproductive and non-reproductive seasons (3.96 ± 0.11 vs. 3.06 ± 0.36 and 173.48 ± 12.26 vs. 63.92 ± 14.75, respectively). Correlations were found between aggressiveness and cloacal size during the reproductive (r=0.18; p=0.04) and non-reproductive (r=0.38; p=0.03) seasons, coloration of peak and cinnamon and cloacal size during the reproductive (r=0.67; p<0.0001) and non-reproductive seasons (r=0.68; p<0.0001), levels of total serum testosterone and cloacal size during the reproductive (r=0.43; p<0.0001) and non-reproductive season (r=0.51; p=0.0028), serum levels of testosterone and coloration of cinnamon and peak during the reproductive (r=0.53; p<0.0001) and non-reproductive (r=0.72; p<0.0001). Also positive correlations were observed between kantling and aggressiveness in the reproductive period (r=0.29; p<0.0008), serum level of testosterone and corticosterone in the reproductive period (r=0.43; p<0.0015) and between kantling and color of cinnamon and peak in the non-reproductive period (r=0.36; p<0.04) for the ostriches of the experiment. In the second part of the experiment 30 male ostriches were classified in three levels (level 1 - birds with bigger cloacal size, bigger degree of aggressiveness and coloration; level 2 - birds with medium cloacal size, medium degree of aggressiveness and coloration; level 3 - birds with smaller cloacal size, smaller degree of aggressiveness and less intense coloration) and the total production of eggs, fertile eggs, infertile eggs, contaminated eggs, eggs with embryonic death and total living chicks. Birds from level 1 showed the best indexes for total egg production, fertile eggs and total living chicks in comparative to the birds of the level 3. The results of the present experiment indicated the existence of a relation between the serum levels of testosterone and the sexual characteristics of ostriches, such as cloacal size and degree of coloration, beyond describing the existence of a relation between the secondary sexual characteristics and behavior of male ostriches and some of its indices of production.

Várias doenças músculo esqueléticas foram observadas em aves de rápido crescimento, sendo o elevado peso corporal, associado a uma estrutura óssea em formação, citados como as principais causas responsáveis pela ocorrência destas doenças, resultando em disfunções do aparelho locomotor. Apesar do estudo do membro pélvico do avestruz merecer a atenção de pesquisadores desde o século XIX, tendo sido descrito no tocante à miologia, principalmente, a osteologia e o estudo radiográfico e morfológico envolvidos na RTT ainda não receberam a devida atenção. O presente trabalho teve como objetivo fazer um estudo anátomo-patológico e radiográfico das estruturas envolvidas na rotação tibiotársica, assim como estudar as alterações articulares através de artrografias e histologia fazendo uma descrição das considerações anatômicas, macroscópicas, microscópicas e radiográficas do membro pélvico do avestruz (African Black). Para este estudo foram utilizadas trinta avestruzes, com idade entre um mês a um ano de idade, apresentando deformidade de membros pélvicos uni ou bilateral. Dessa forma, será possível contribuir para o entendimento desta enfermidade, que tem causado perdas para a estrutiocultura. / Ostrich?s hind limbs study: Anatomical, radiographic and histological considerations of the tibiotarsus rotation. Many skeletal muscles diseases were observed in fast growth, been the hight body wight, to associate with a bone structure in formation citads with the principal responsible cases for ocorrence these deseases, have been disfunction of locomotor arrangment. Despite the fact that the ostrich?s hind limbs have deserved attention from researchers since the 19th century, the myological and osteological descriptions together with the radiographic and morphological study, which involves RTT, have not received any attention yet. This present research intends to make an anatomical, pathological and radiographic study of the structures involved in the tibiotarsus rotation, besides the study of the joint alterations by arthrography and histology, giving one description with anatomical, macroscopic, microscopic and radiographic considerations of the ostrich?s hind limbs. This way, it?ll be possible to contribute to the comprehension of this disease that has caused many losses on the ostrich farm.

This work investigated the design parameters necessary for the build and use of an in vitro artificial mouth model built for dental erosion research. It also ascertained the working knowledge of dentists concerning the Human Tissue Act (HTA) and explored an alternative tissue for erosion-testing to human enamel. The design inputs for the artificial mouth were acquired by an innovative observational study conducted upon human volunteers and used in the decisions made in the setting of the fluids’ kinematic behaviour and how the associated devices were to function. This novel system was sought to mimic the interaction of saliva and the dental substrate during the process of consuming an erosive beverage. The model allows researchers to gather data using customizable experimental diets without the technical burden of dealing with a non-realistic regime. The design and build of the artificial mouth model along with its associated equipment and parameters are described and a manual for operation of the model is appended. The device is designed on a fully adjustable multitask basis in which the operator can set several variables such as the desirable salivary kinematic behaviour, offensive beverage flow rate, and volume of consumption. This, subsequently, allows the samples preloaded on the system to be tested for surface characteristics (i.e. surface hardness and surface profilometry) to determine the extent of erosion if any. The model also allows the resultant solution to be analysed for traces of calcium and phosphate ions. To validate the capabilities of the artificial mouth system a set of diets was performed repeatedly. The high degree of agreement and the consistency of results showed that the model is able to mimic realistic scenarios and is capable of producing reliable, reproducible and accurate outcomes. Ostrich eggshell proved to be a potential alternative erosion substrate which is fortuitous as the lack of knowledge on the HTA had meant human enamel was less readily available.

Previous literature has produced mixed findings of a tendency of investors, coined the “ostrich effect” to display a preference for avoiding potentially painful information regarding their portfolios. This paper investigates the presence of the ostrich effect during the 2008/2009 financial crisis via a survey of investors who held portfolios before and through that period. The results demonstrate that most investors do not report any ostrich effect. However, approximately one fourth of investors demonstrated a preference for delaying learning about potentially negative portfolio information, but ultimately chose to learn the information. These findings provide a more nuanced understanding of investors’ behaviors during financial crises and supports a more specific definition of the ostrich effect. Specifically, that some investors prefer a delay in painful information acquisition but do no indefinitely “keep their heads in the sand.”

The aim of this research was to identify how farmers learn how to farm using pluriactive lifestyle block ostrich farmers who are part of the New Zealand ostrich industry as a case study. Ostrich farming is comparatively new to New Zealand farmers and the industry has attracted innovative individuals who have developed informal learning strategies. Ostrich farmers use other farmers as their main resource which is mainly facilitated through events organised by the New Zealand Ostrich Association (NZOA) and aimed at lifestyle block farmers. Ostrich farmers' community of practice is centred around their membership to the Association which enables farmers to come together to learn and socialise. For learning to effectively take place the key is social interaction, where ideas can be transferred between farmers. This thesis illustrates the important events and structure of the industry and how this has shaped farmer learning. Through semi-structured interviews and participant observation on a chick rearing farm I was able to gain a picture of how lifestyle block farmers balance full time off-farm employment while running stock, in an attempt to satisfy their version of the rural idyll. The industry is now in decline as most of the early players have exited the industry and it is now focused around New Zealand Ostrich Export (NZOE) goals. By exploring the period called the breeder phase which was characterised by some farmers making a fortune as ostrich farming was the 'next big thing' and the history since then, I have identified how these particular farmers have learned how to farm.

Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Fresh ostrich meat competes in well regulated and competitive international markets; therefore food quality and safety are of the utmost importance. At the same time the production process must be well controlled to be cost effective. Losses in meat yield through bruising and the trimming thereof as well as a high initial microbial load that causes a decrease in shelf-life is thus undesirable. The main objectives of this study were firstly to investigate the expected prevalent microbial growth on ostrich meat as well as possible environmental contaminants to establish which bears the greatest risk. Secondly to establish the best practice of removing bruised areas from carcasses from both a microbiological and meat yield perspective. Lastly to investigate bruises on carcasses to predict the possible causes thereof so as to minimize bruising during transport and handling. From this study it was concluded that the prevalent growth on carcasses was predominantly Grampositive which increased ten fold from post-evisceration to post-chilling, this was also associated with a marked increase in Gram-negative organisms. The most dangerous vector for contamination was found to be standing water containing Gram-negative human pathogens including Shigella, Salmonella and E. coli. Bruises to the necks (52.58% of all bruises) were the most frequent, the high side railings on transport trucks the probable cause thereof. It was indicated that aerobic viable counts decreased after cold trimming, where the opposite occurred on warm trimmed surfaces, while the average loss in meat yield per bird due to bruising was smaller for cold trimming. / AFRIKAANSE OPSOMMING: Vars volstruisvleis kompeteer in goed gereguleerde en kompeterende internasionale markte; dus is voedselkwaliteit en –veiligheid baie belangrik. Terselfdertyd moet die produksieproses goed beheer word en koste effektief wees. Verliese aan vleisopbrengs as gevolg van kneusings en die verwydering daarvan, sowel as ‘n hoë inisiële mikro-organisme lading wat ‘n verkorte rakleeftyd tot gevolg het, is dus ongewens. Die hoofdoelwitte van die studie was eerstens om die verwagte mikro-organisme groei op volstruisvleis en op moontlike omgewings kontaminasie bronne te ondersoek om vas te stel watter bronne die grootste risiko dra vir besmetting. Tweedens om die beste praktyd vir die verwydering van kneusings van die volstruiskarkasse te bepaal uit beide ‘n mikrobiologiese en vleisopbrengs oogpunt. Laastens om die omvang en verspreiding van karkaskneusings te ondersoek om die oorsaak daarvan te probeer aandui en sodoende kneusings tydens vervoer en hantering te verminder. Uit die studie was die volgende duidelik; die mikrobiese groei op karkasses was hoofsaaklik Gram-positief, tellings het tienvoudig toegeneem vanaf ontweiding tot na verkoeling, met ‘n gepaardgaande merkbare toename in Gram-negatiewe organismes. Die gevaarlikste oorsaak van omgewingskontaminasie was staande water wat Gram-negatiewe menslike patogene (insluitend; Shigella, Salmonella en E. coli) bevat het. Nekkneusings (52.58% van all kneusings) was die algemeenste; met die hoogte van die kantreëlings van die volstruistrokke die moontlike oorsaak daarvan. Dit is bewys dat die aerobe mesofiele plaattelings afgeneem het na koue verwydering, maar dat die teenoorgestelde gesien is op warm gesnyde areas; die gemiddelde verlies in vleisopbrengs per volstruis as gevolg van kneusingverwydering is kleiner tydens koue verwydering.

Made available in DSpace on 2015-04-17T14:49:13Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1407033 bytes, checksum: 932b37f811919fe1ee5f9dbb0e27dce4 (MD5) Previous issue date: 2011-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Brazil is a developing country in which a significant proportion of the population has limited access to fresh meat, and as a substitutive for this item the alternative is the consume of meat derivated products, so it is high the consumption of products such as sausages and mortadella in Brazil. The aim of this study was to analyze the performance of ostrich meat from the deboned leg, the physical and chemical characteristics and the development and evaluation of smoked sausage from this meat. It was done the proximate composition, instrumental color, pH, water activity (aw), the instrumental texture, emulsification capacity and water absorption capacity of ostrich meat. For the development of smoked mortadella with modified starch and soybean oil was used a complete23 factorial design with 3 central points. It was assessed the stability of the emulsion, microbiological characteristics, proximate composition, instrumental color, pH, water activity (wa), the instrumental texture, capacity to retain water, the juice released from the packaging, weight loss from cooking and sensory evaluation of mortadella. Ostrich meat had presented excellent performance after deboned (87.27%), good percentage of macronutrients, highlighting the low amount of fat, good absorption capacity of oil and water. The mortadella presented a humidity varying from 71,56±0,72 to 68,17±0,52, lipids 10,86±0,31% to 15,84±1,11%, RMF 1,56±0,19% to 1,01±0,02%, protein from 15,23±0,73% to 12,40±0,49% and carbohydrates from 2,36±1,34% to 1,30±0,08%, instrumental texture of 0,13±0,01 the 0,29±0,05 Kgf/cm2, instrumental color for the parameter L * 52,83±0,42 to 60,96±0,58, the * 8,60±0,13 to 12,29±0,28, b * 11,36±0,04 to 13,84±0,16, stability of the emulsion from 48±0,43% to 86,61±0,79%, juice released from the packaging from 4,23±0,20% to 7,47±0,84%, weight loss from cooking from 1,40±0,24% to 10,92±0,00%, capacity of retention of water varied of 0,27±0,02% the 0,37±0,09%, pH in the rate from 6,29±0,00 to 6,52±0,03, 0,97±0,00 water activity of 0,98±0,00, and a good sensorial acceptance and purchase intention. It was possible to observe in this experiment that is feasible the elaboration of sausages with ostrich meat, with modified starch, soy oil and liquid smoking, maintaining the nutritional and technological qualities, which demonstrates the viability of its production. / O Brasil é um país em desenvolvimento e uma parte significativa da população tem restrito acesso a carne in natura, tendo apenas possibilidade de aquisição de derivados cárneos, por isso, é alto o consumo de produtos embutidos no Brasil. O objetivo deste estudo foi analisar o rendimento da carne da perna de avestruz pós-desossada, as características físicas e químicas e o desenvolvimento e avaliação de mortadela defumada. Foi realizada a composição centesimal, a cor instrumental, o pH, a atividade de água (aw), a textura instrumental, a capacidade de emulsificação e a capacidade de absorção de água da carne de avestruz. Para o desenvolvimento das mortadelas defumadas com amido modificado e óleo de soja foi utilizado um planejamento fatorial completo 23 com 3 pontos centrais. Avaliou-se a estabilidade da emulsão, características microbiológicas, a composição centesimal, a cor instrumental, o pH, a atividade de água (aw), a textura instrumental, a capacidade de retenção de água, o suco exsudado da embalagem, a perda de peso por cozimento e análise sensorial das mortadelas. A carne de avestruz apresentou um excelente rendimento pós-dessosa (87,27%), bom percentual de macronutrientes, ressaltando a baixa quantidade de gordura, boa capacidade de absorção de óleo e de água. As mortadelas apresentaram uma umidade variando de 71,56±0,72 a 68,17±0,52, lipídios 10,86±0,31% a 15,84±1,11%, RMF 1,56±0,19% a 1,01±0,02%, proteína de 15,23±0,73% a 12,40±0,49% e carboidratos de 2,36±1,34% a 1,30±0,08%, textura instrumental de 0,13±0,01 a 0,29±0,05 Kgf/cm2, cor instrumental para o parâmetro L* 52,83±0,42 a 60,96±0,58, a* 8,60±0,13 a 12,29±0,28, b* 11,36±0,04 a 13,84±0,16, estabilidade da emulsão de 48±0,43% a 86,61±0,79%, exsudato da embalagem de 4,23±0,20% a 7,47±0,84%, perda de peso por cozimento de 1,40±0,24% a 10,92±0,00%, capacidade de retenção de água variou de 0,27±0,02% a 0,37±0,09%, pH na faixa de 6,29±0,00 a 6,52±0,03, atividade água de 0,97±0,00 a 0,98±0,00, e uma boa aceitação sensorial e intenção de compra. Foi possivel observar neste experimento que é viável a elaboração de mortadelas com carne de avestruz, com amido modificado, óleo de soja e defumação líquida, mantendo as qualidades nutricionais e tecnológicas, o que demonstra a viabilidade de sua produção

This thesis deals with the problem of commercial properties of an African ostrich collected on farms in the Czech Republic. Literature review focuses on the history, origin, economic benefits and also the breeding conditions. This work evaluates the utility of selected properties of ostrich farms in the Czech Republic. The values obtained were well described and evaluated by appropriate methods. Egg-laying farms was observed in the range from 15 to 50 pieces (mean 29.07 pieces), the weight of eggs ranged from 1.22 to 1.89 kg (mean 1.51 kg), fertilization of eggs were in the range from 54.55?86.00% (mean 76.36%) and a hatching rate was in the range of 31.82?52.77% (mean 44.61%). Weight of meat obtained from slaughter ostrich ranged from 30 to 50 kg (mean 39.74 kg), the skin area was in the range from 1.10 to 1.50 m2 (mean 1,34 m2) and the production of feathers was from 1.36 to 1.50 kg.

The introduction of new species within the cattle sector has been growing and among the most representative animals in this sector is the ostrich (Struthio camellus). Although generating benefits, these activities are difficult to be deeply studied in terms of their physiology, pathology and clinics due to the speed they evolve. Many physiological parameters which are essential for the diagnosis of disturb and diseases are not available. Thus, the objective of this work was to outline the plasmatic protein electrophoresis profile of ostrich, as well as to identify differences among the fractions of these proteins among specific age groups. Blood samples of 72 ostriches were collected in different farms in Rio Grande do Sul. The samples were distributed in six groups, according to the animal s age and gender, in which 2 were chick, 2 young and 2 adults. These samples were submitted to the biuret method and to the electrophoresis, for quantification, separation and identification of proteins. Along the same line of study, there were also processed and analyzed 9 blood samples of adult rheas (Rhea americana) and a couple of emus (Dromaius novaehollandiae), these animals that, along with the ostrich, which also belong to the Struthioniformes order. The levels of Total Proteins (PPT) and the relation between Albumin and Globulin (A/G) were found and determined through the biuret method and the technique of electrophoresis. For each group of female ostrich chick, the average PPT was 2.23 ± 0.23g/dL, for male chick it was 2.40 ± 0.30g/dL, for young females the average was 3.67 ± 0.42g/dL and young males it was 3.90 ± 0.44g/dL; the adult females presented an average of 4.11 ± 0.65g/dL and the adult males, 4.07 ± 0.69g/dL. For the group of adult rheas were found average values of 5:22 ± 0.66 g / dL of total plasma proteins and 0.97 ± 0.24 for the relationship between albumin and globulins. For a couple of emus, in turn, resulted in values of 5.30 g / dL and 4.10 g / dL of plasma total protein and 0.67 and 0.81 for the ratio of albumin and globulin, for female and male respectively. The protein fractions were defined as albumin, alpha-globulin, beta 1-globulin, beta2-globulin e gamma-globulin for the three species. / A introdução de novas espécies dentro do setor pecuário vem crescendo e entre os animais que figuram, com importância, está o avestruz (Struthio camellus). Essas atividades geram benefícios, mas, a velocidade com que evoluem dificulta o acompanhamento de estudos aprofundados e seguros sobre fisiologia, patologia e clínica desses animais. Muitos parâmetros fisiológicos não estão disponíveis, sendo estes imprescindíveis para o diagnóstico de distúrbios e enfermidades. Desse modo, o objetivo deste trabalho foi traçar o perfil eletroforético de proteínas plasmáticas de avestruzes, bem como identificar diferenças nas frações dessas proteínas entre determinadas faixas etárias. Para tanto, foram coletadas amostras de sangue de 72 avestruzes de diferentes criatórios do Rio Grande do Sul, distribuídos em seis grupos, por idade e por sexo, sendo 2 de filhotes, 2 de juvenis e 2 de adultos. Essas amostras passaram pela realização do método de biureto e pela eletroforese, para a quantificação, separação e identificação das proteínas. Dentro da mesma linha de estudo, foram processadas e analisadas 9 amostras de sangue de emas (Rhea americana) adultas e de um casal de emus (Dromaius novaehollandiae), animais esses que, junto com o avestruz, também pertencem à ordem Struthioniformes. Foram encontrados e determinados os níveis de proteínas plasmáticas totais (PPT) e a relação entre albumina e globulinas (A/G), por meio da realização do método de biureto e da técnica da eletroforese. Para o grupo de avestruzes filhotes fêmeas, a média de PPT foi de 2.23 ± 0.23g/dL, para os filhotes machos foi 2.40 ± 0.30g/dL; para as fêmeas juvenis a média foi de 3.67 ± 0.42g/dL e para os machos juvenis foi 3.90 ± 0.44g/dL; as fêmeas adultas, por sua vez, apresentaram uma média de 4.11 ± 0.65g/dL e os machos adultos, 4.07 ± 0.69g/dL. Para o grupo das emas foram encontradas médias de valores de 5.22 ± 0.66 g/dL de proteínas plasmáticas totais e 0.97 ± 0.24 para a relação entre a albumina e as globulinas. Para o casal de emus, por sua vez, obteve-se valores de 5,30 g/dL e 4,10 g/dL de proteínas plasmáticas totais e 0,67 e 0,81 para a relação entre a albumina e as globulinas, para a fêmea e o macho respectivamente. As frações protéicas, nesse estudo, foram definidas como albumina, alfa-globulina, beta1-globulina, beta2-globulina e gama-globulina, para as três espécies.

Made available in DSpace on 2014-06-11T19:32:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-19Bitstream added on 2014-06-13T21:03:40Z : No. of bitstreams: 1 ramos_sb_me_jabo.pdf: 520535 bytes, checksum: 6d50ca4d7611871079ff37f8e15c9d68 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Medidas periódicas de peso corporal de avestruzes (Struthio camelus) foram utilizadas para avaliar o desenvolvimento corporal por meio de modelos não lineares e para obter estimativas de herdabilidade para pesos ao nascer (PN), aos 90 (P90) e aos 180 dias de idade (P180). As funções estudadas foram: Brody, Richards, von Bertalanffy, Gompertz e Logístico, pelo método de Gauss Newton, por meio de regressão não-linear das características em função da idade (dias). As estimativas de herdabilidade foram obtidas pelo método de máxima verossimilhança restrita. Todos os modelos não-lineares ajustaram parâmetros para o crescimento corporal, exceto Richards e Brody. O modelo Gompertz foi o mais adequado para representar o crescimento, conforme a interpretação biológica dos parâmetros e a qualidade do ajuste. As estimativas de herdabilidade foram de 0,42±0,05, 0,16±0,04 e 0,24±0,08 para PN, P90 e P180, respectivamente. Todas as características poderão responder à seleção / Periodic measurements of body weight of ostriches (Struthio camelus) was used to evaluate the body development by nonlinear models and to fit heritability estimates of hatched chick weight (CHWT) and live weights recorded at 90 (LW90) and 180 (LW180) days of age. The studied models were: Brody, Richards, von Bertalanffy, Gompertz and Logistic, by Gauss-Newton method, on nonlinear regression of the traits in function of the age (days). The heritability estimates were obtained by restricted maximum likelihood method. All the nonlinear models fitted parameters for body growth, except Richards and Brody. The Gompertz model was the more appropriate to represent the growth, considering the biological interpretation of the parameters and the quality of the fitting. The heritability estimates were 0,42±0,05, 0,16±0,04 and 0,24±0,08 for CHWT, LW90 and LW180 respectively. All the traits can respond to selection