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.

Effects of various levels of L-ascorbic acid (L-AA) (12 and 25 mg) in ovo injected at 17 and 18 days of incubation, on embryonic and posthatch physiological variables in Ross 708 broilers were investigated. There were no significant treatment effects on the hatchability or serum concentrations of L-AA in the broilers. Eye L-AA concentrations were higher, and plasma nitric oxide levels were lower in male chicks treated in ovo with 12 mg of L-AA. While exposed to elevated atmospheric NH3 levels, the in ovo injection of 12 mg of L-AA increased the body weight gain and decreased the feed conversion ratio of the broilers from 0 to 28 days of age (doa). Decreased tracheal attenuation incidence was also experienced at 0 doa in the in ovo injected L-AA groups, and tracheal inflammation was significantly reduced at 28 doa in response to the in ovo injection of 12 mg of L-AA.

O objetivo deste trabalho foi avaliar os efeitos das vibrações mecânicas decorrentes do transporte sobre a qualidade de ovos fertilizados e sobre o nascimento e a qualidade de pintos de corte. O experimento foi dividido em duas fases desenvolvidas em um incubatório comercial em Mogi-Mirim/SP. Na primeira, 1920 ovos fertilizados de matrizes da linhagem Cobb-500 (31 a 34 semanas) foram expostos a simulações dos movimentos vibratórios, produzidos por um agitador mecânico desenvolvido para este fim. Na segunda fase, esses ovos foram incubados até o nascimento das aves. Avaliaram-se os efeitos de diferentes intensidades de vibração e tempos de exposição sobre as respostas de interesse. A intensidade foi definida por duas faixas de vibração simuladas pelo agitador (faixa inferior; RSS de 2,5 m.s-2 e faixa superior; RSS de 7,5 m.s-2), as quais foram associadas a dois tempos de exposição, um mínimo e um máximo (60 e 180 minutos, respectivamente). Foi adotado um delineamento aleatorizado em blocos com tratamentos em esquema fatorial mais um controle (2 x 2 + 1). A qualidade dos ovos fertilizados foi mensurada a partir da perda de peso e de medidas tomadas na gema e no albúmen (altura, diâmetro e índices, e unidade Haugh). Pela análise de variância foi possível observar efeitos dos fatores experimentais na qualidade dos ovos fertilizados, principalmente nas medidas tomadas no albúmen. Os resultados indicaram que os ovos quando expostos às vibrações, em faixas mais intensas e/ou por mais tempo, apresentam seu albúmen liquefeito, o que é um sinal de perda de qualidade. Esses resultados foram comprovados pela redução no índice de albúmen e na unidade Haugh, quando realizados os testes t e de Tukey a 5% de significância. Após o nascimento das aves foi avaliada a taxa de eclodibilidade, a caracterização da mortalidade e a qualidade dos pintos de corte (peso absoluto e classificação). Por meio da regressão logística, observou-se que a exposição dos ovos fertilizados às vibrações pode afetar negativamente a taxa de eclodibilidade e a proporção de pintos classificados em primeira linha. Essas respostas foram menores pelo teste de Wald a 5% de significância no tratamento formado pela faixa de vibração superior aplicada por mais tempo. Os piores resultados no nascimento refletiram diretamente em um aumento nas perdas totais devido à exposição dos ovos aos movimentos vibratórios, com a significância de efeito comprovada principalmente pela a faixa de vibração. Além disso, pela análise de variância foi observada uma pequena redução do peso das aves nascidas de ovos vibrados, quando feita a comparação de médias pelo teste t com o controle. Por fim, acredita-se que o comprometimento da qualidade do albúmen tenha gerado piores resultados no nascimento e na qualidade dos pintos de corte. Dessa forma, é possível concluir que a exposição às vibrações pode comprometer a incubação e gerar prejuízos de grandes dimensões para os incubatórios, caso ocorram em condições semelhantes às simuladas nesta pesquisa. / The aim of this research was to evaluate the effects of mechanical vibrations during birth, and on the quality of fertile eggs and broiler chicks due to transportation. The experiment was divided in two phases developed in a commercial incubator in Mogi-Mirim, São Paulo. In the first phase, 1920 fertile eggs from Cobb-500 matrix (31 to 34 weeks) were used. These eggs were exposed to vibrations in a mechanical simulator. In the second phase, the eggs were incubated until the moment of birth. The effects of different vibration intensities and time exposition upon different feed backs were assessed. The intensity was defined by two vibration levels simulated by a mechanical agitator (inferior level; RSS - 2.5 m.s-2; superior level; RSS - 7.5 m.s-2), in which were associated to two different exposition periods of time (minimum, 60 minutes; and maximum, 180 minutes, respectively). A modeling in blocks with treatments in a factorial treatment and a control (2 x 2 +1) was chosen randomly. The quality of fertile eggs was evaluated considering the weight loss and measurements taken in the egg yolk and in the albumen (height, diameter, indexes, and Haugh unity). Using the analysis of variance, it was possible to observe the effects of experimental factors on the quality of fertile eggs, mainly, in the measurements found in the albumen. The results indicated that the eggs that were exposed to vibrations in very intense levels, and/or for more time, presented liquefied albumen, showing quality loss. These results were seen by the reduction in the albumen index as well as in the Haugh unity, found in the Tukey test submitted to the level of significance of 5%. After birth, the hatching tax, the mortality characterization, and the quality of broiler chicks (absolute weight and classification) were evaluated. Using the logistical regression, it was possible to observe that fertile eggs exposed to vibrations can affect negatively the hatching tax and the proportion of chicks classified in first line. These results were found smaller in the Wald test at significance of 5% in the treatment formed by the superior vibration level applied for a longer period of time. The worst results found in birth demonstrated an increase in total loss because of vibration exposition on the eggs with a significance effect proved, mainly, by the vibration level. Furthermore, through the analysis of variance, it was observed a small weight reduction of birds hatched from vibrated eggs. These results were observed when they were compared to the averages found in the control group and t test. Thus, if the albumen quality is compromised it is believed that it generates worst results in birth and in the quality of broiler chicks. Hence, it is possible to conclude that vibrations are capable of compromise incubation, resulting in huge financial loss for incubators, if similar conditions happen to be the way they were simulated on this study.

O objetivo deste trabalho foi avaliar os efeitos das vibrações mecânicas decorrentes do transporte sobre a qualidade de ovos fertilizados e sobre o nascimento e a qualidade de pintos de corte. O experimento foi dividido em duas fases desenvolvidas em um incubatório comercial em Mogi-Mirim/SP. Na primeira, 1920 ovos fertilizados de matrizes da linhagem Cobb-500 (31 a 34 semanas) foram expostos a simulações dos movimentos vibratórios, produzidos por um agitador mecânico desenvolvido para este fim. Na segunda fase, esses ovos foram incubados até o nascimento das aves. Avaliaram-se os efeitos de diferentes intensidades de vibração e tempos de exposição sobre as respostas de interesse. A intensidade foi definida por duas faixas de vibração simuladas pelo agitador (faixa inferior; RSS de 2,5 m.s-2 e faixa superior; RSS de 7,5 m.s-2), as quais foram associadas a dois tempos de exposição, um mínimo e um máximo (60 e 180 minutos, respectivamente). Foi adotado um delineamento aleatorizado em blocos com tratamentos em esquema fatorial mais um controle (2 x 2 + 1). A qualidade dos ovos fertilizados foi mensurada a partir da perda de peso e de medidas tomadas na gema e no albúmen (altura, diâmetro e índices, e unidade Haugh). Pela análise de variância foi possível observar efeitos dos fatores experimentais na qualidade dos ovos fertilizados, principalmente nas medidas tomadas no albúmen. Os resultados indicaram que os ovos quando expostos às vibrações, em faixas mais intensas e/ou por mais tempo, apresentam seu albúmen liquefeito, o que é um sinal de perda de qualidade. Esses resultados foram comprovados pela redução no índice de albúmen e na unidade Haugh, quando realizados os testes t e de Tukey a 5% de significância. Após o nascimento das aves foi avaliada a taxa de eclodibilidade, a caracterização da mortalidade e a qualidade dos pintos de corte (peso absoluto e classificação). Por meio da regressão logística, observou-se que a exposição dos ovos fertilizados às vibrações pode afetar negativamente a taxa de eclodibilidade e a proporção de pintos classificados em primeira linha. Essas respostas foram menores pelo teste de Wald a 5% de significância no tratamento formado pela faixa de vibração superior aplicada por mais tempo. Os piores resultados no nascimento refletiram diretamente em um aumento nas perdas totais devido à exposição dos ovos aos movimentos vibratórios, com a significância de efeito comprovada principalmente pela a faixa de vibração. Além disso, pela análise de variância foi observada uma pequena redução do peso das aves nascidas de ovos vibrados, quando feita a comparação de médias pelo teste t com o controle. Por fim, acredita-se que o comprometimento da qualidade do albúmen tenha gerado piores resultados no nascimento e na qualidade dos pintos de corte. Dessa forma, é possível concluir que a exposição às vibrações pode comprometer a incubação e gerar prejuízos de grandes dimensões para os incubatórios, caso ocorram em condições semelhantes às simuladas nesta pesquisa. / The aim of this research was to evaluate the effects of mechanical vibrations during birth, and on the quality of fertile eggs and broiler chicks due to transportation. The experiment was divided in two phases developed in a commercial incubator in Mogi-Mirim, São Paulo. In the first phase, 1920 fertile eggs from Cobb-500 matrix (31 to 34 weeks) were used. These eggs were exposed to vibrations in a mechanical simulator. In the second phase, the eggs were incubated until the moment of birth. The effects of different vibration intensities and time exposition upon different feed backs were assessed. The intensity was defined by two vibration levels simulated by a mechanical agitator (inferior level; RSS - 2.5 m.s-2; superior level; RSS - 7.5 m.s-2), in which were associated to two different exposition periods of time (minimum, 60 minutes; and maximum, 180 minutes, respectively). A modeling in blocks with treatments in a factorial treatment and a control (2 x 2 +1) was chosen randomly. The quality of fertile eggs was evaluated considering the weight loss and measurements taken in the egg yolk and in the albumen (height, diameter, indexes, and Haugh unity). Using the analysis of variance, it was possible to observe the effects of experimental factors on the quality of fertile eggs, mainly, in the measurements found in the albumen. The results indicated that the eggs that were exposed to vibrations in very intense levels, and/or for more time, presented liquefied albumen, showing quality loss. These results were seen by the reduction in the albumen index as well as in the Haugh unity, found in the Tukey test submitted to the level of significance of 5%. After birth, the hatching tax, the mortality characterization, and the quality of broiler chicks (absolute weight and classification) were evaluated. Using the logistical regression, it was possible to observe that fertile eggs exposed to vibrations can affect negatively the hatching tax and the proportion of chicks classified in first line. These results were found smaller in the Wald test at significance of 5% in the treatment formed by the superior vibration level applied for a longer period of time. The worst results found in birth demonstrated an increase in total loss because of vibration exposition on the eggs with a significance effect proved, mainly, by the vibration level. Furthermore, through the analysis of variance, it was observed a small weight reduction of birds hatched from vibrated eggs. These results were observed when they were compared to the averages found in the control group and t test. Thus, if the albumen quality is compromised it is believed that it generates worst results in birth and in the quality of broiler chicks. Hence, it is possible to conclude that vibrations are capable of compromise incubation, resulting in huge financial loss for incubators, if similar conditions happen to be the way they were simulated on this study.

Orientador: Nelson Luis Cappelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-13T07:46:45Z (GMT). No. of bitstreams: 1 Romanini_CarlosEduardoBites_M.pdf: 1656027 bytes, checksum: eacfb3ae714a9b008469fac75bd1149b (MD5) Previous issue date: 2009 / Resumo: Dentro do complexo econômico de produção de carnes, a avicultura se constitui na atividade mais dinâmica e o Brasil possui uma das mais desenvolvidas aviculturas comerciais do mundo. Diante das atuais exigências na qualidade e segurança do produto, a moderna indústria avícola brasileira tem progredido, essencialmente pela adoção crescente de novas tecnologias. Na cadeia toda, a incubação dos ovos representa a origem do processo, pois é responsável por transformar biologicamente ovos férteis em pintos de um dia de idade. Em escala industrial, utilizam-se máquinas incubadoras para reproduzir as condições naturais de incubação das aves, objetivando elevar, ao máximo, o índice de eclosão e a qualidade de nascimento dos pintos. Porém, o desenvolvimento embrionário no interior dos ovos é substancialmente afetado pelas condições ambientais da incubadora. Os embriões não são aptos para controlar as trocas térmicas e mássicas durante a incubação; assim, as principais variáveis ambientais que exercem influência no processo, como temperatura e umidade relativa do ar, necessitam ser criteriosamente ajustadas, pois manter as condições adequadas ao redor dos ovos é um ponto crítico de controle do processo. Conhecimentos das áreas de automação e controle são capazes de influenciar positivamente o rendimento na incubação, portanto, o sistema de controle deve garantir a estabilidade operacional para as condições do processo e suas variáveis, dentro de limites desejados. O controle fuzzy é o mais adequado, para processos que apresentam não-linearidades e comportamento transiente, uma vez que descrevem numa rotina, a experiência humana para controlar o processo. Diante desse contexto, propôs-se, no presente estudo, desenvolver uma arquitetura de automação composta por um sistema de controle fuzzy, para proporcionar um controle mais preciso das variáveis de interesse na incubação. O estudo foi desenvolvido em duas etapas, sendo: 1) ensaio experimental de identificação dinâmica e modelagem matemática de uma incubadora de estágio único; e 2) simulação do processo de incubação dos ovos. Foi desenvolvido um modelo computacional da incubadora composto pela representação matemática da incubadora, pelas interações de transferência de calor e massa entre os ovos e o ambiente e, pelo sistema de inferência fuzzy utilizado para controlar o processo de incubação. A simulação proporcionou a execução de diversos cenários operacionais da incubadora, possibilitando o ajuste adequado para o sistema de controle proposto. Obteve-se, como principal resultado o comportamento ao longo do tempo das seguintes variáveis: temperatura dos ovos e do ambiente, massa dos ovos, umidade relativa do ar, produção de calor embrionária, detalhes da interação entre ovo e ambiente e as condições de atuação da incubadora estudada. Os resultados obtidos foram comparados aos valores de referência da literatura, indicando diferenças mínimas entre a temperatura dos ovos e o seu valor de referência. Os resultados relativos à massa de ovos tiveram desempenho abaixo do esperado e, para tal, o sistema de controle precisa receber ajustes. De maneira geral, foram obtidos conhecimentos técnicos mais apurados da incubação, que podem ser úteis para implementação real do sistema de controle desenvolvido. / Abstract: Within the meat production economical complex broiler production is the most dynamic activity, and Brazil has one of the world most developed commercial broiler production. Facing today's needs in terms of quality and safety of the product, modern Brazilian poultry production has improved essentially by the increasing adoption of new technologies. In the whole chain eggs incubation represents the origin of the process; as it is responsible of transforming biologically fertile eggs intone day old chicks. In the industrial scale incubator machines are used to reproduce natural bird's incubation conditions with the objective of increasing at its maximum the hatching index as well birth quality of the broilers. However, the embryonic development inside the eggs is substantially affected by the environmental conditions within the incubator. Embryos are not apt to control heat or mass exchanges during incubation; then, the main ambient variables which influence the process such as air temperature and relative humidity need to be adjusted with criterion, as maintaining the adequate conditions around the eggs is a critical control point of the process. Knowledge on the automation and control areas is able to positively influence incubator efficiency; then, the control system must warrant operational stability for the process conditions as well as its variables, within certain wanted limits. fuzzy control is the most adequate use for the processes which present non-linearity and transient behavior, since it describes in a routine the human experience for controlling the process. In this context it was proposed in the present study to develop an automation architecture composed by a fuzzy control system in order to provide more precise control of the variables that are of interest on incubation. The study was developed in two stages, being 1) and experimental trial of dynamic identification and mathematical modeling of an incubator of single stage; and 2) process simulation of eggs incubation. It was developed a computer model of the incubator built from the mathematical representation of the incubator, the interaction of the heat and mass transfer between the eggs and the environment, and by the fuzzy inference system used for controlling the incubation process. Simulation led to built up various incubators operational scenarios providing the adequate adjustment for the proposed control. It was found as main result the behavior of the following variables along the time: eggs' and ambient temperatures, eggs mass, air relative humidity, embryonic heat production, details of the eggs and ambient, and the studied incubators performing conditions. The obtained results related to eggs mass were below the expected, and for that the control system needs to be adjusted. Generally technical knowledge regarding incubation were achieved, and they may be useful for implementing a real control system. / Mestrado / Maquinas Agricolas / Mestre em Engenharia Agrícola

Northern bobwhite populations have declined concurrent with global warming. The focal period of this study was the 12-d pre-incubation period, when bobwhite eggs remain in the nest without the thermal protection of the incubating parent. This study first established the storage and thermal limits of bobwhite eggs, then investigated how global warming may impact oviparous embryos and how bobwhite embryos react to acute and chronic doses of simulated drought temperatures during pre-incubation. First, the maximum storage limit of bobwhite eggs was determined by storing eggs &#8804;21 d and measuring hatching success and pH of egg albumen and yolk. Hatching success of stored eggs declined after 14 d, when yolk and albumen pH reached levels detrimental to embryonic development. Secondly, thermal limits were determined by exposing bobwhite eggs to hyperthermic temperatures (38-52 °C). Bobwhite embryos survived 50 °C for 1 h, 49 °C for 3 h and 46 °C for 6 h. Results indicate an adaptation to the naturally occurring temperature extremes that can occur in the bobwhite's southern range during pre-incubation. Subsequently, bobwhite eggs were exposed to either low constant (LC), low fluctuating (LF), high constant (HC), or high fluctuating (HF) temperatures during pre-incubation to determine if the nature of temperatures differentially affected development. Although eggs exposed to high heat loads (HC and HF), and low heat loads (LF and LC) had equal heating degree-hours within groups, they exhibited differential growth during pre-incubation. Oxygen consumption, hatch timing, and hatching success were also affected by the thermal regimes. Eggs in simulated drought (HF) had a 47% lower hatch rate than eggs in simulated non-drought (LF) indicating that thermal stress during pre-incubation may contribute to population declines during drought. Finally, northern bobwhite eggs were exposed to acute or chronic doses of simulated drought temperatures, which tested for critical periods of development during pre-incubation. Collectively, data indicated that the earliest stages of bobwhite development were more affected by hyperthermic temperatures. Indeed, a critical period of development exists during the first 2/3 of pre-incubation during which exposure to hyperthermic temperatures results in aberrant development, hatching plasticity, and reduced hatch rates.

Antimicrobial proteins contained in the albumen represent maternal effects, including the non- genetic component allocated into the egg during its oogenesis. Especially for species, whose broods are exposed to environmental influences until completation, these proteins play a crucial role in the viability of embryos due to their potential to influence the risk of microbial infection, which is considered one of the main causes of reduced hatchability. Also, it is assumed that these proteins, beacause of their specific traits, may influence phenotype of chicks, especially its size and immunity in the early postembryonal stage. In my thesis I focused on three antimicrobial proteins of avian egg white - avidin, lysozyme and ovotransferrin, which vary in their antimicrobial activity. For a better understanding of causal relationships between the concentrations of these proteins in the albumen and their effect on hatching success or offspring phenotype, a series of manipulation experiments and correlative measurements were performed. These experiments were held on the eggs of two precocial species - Japanese Quail (Coturnix japonica) and Mallard (Anas platyrhynchos). Our results indicate a crucial role of antimicrobial proteins in reducing the risk of bacterial infection and their natural concentration...