O estudo consistiu em quatro experimentos com o objetivo de avaliar a redução proteica e níveis de metionina+cistina sobre o desempenho e qualidade de ovos (produção de ovos, consumo de ração, conversão alimentar, peso de ovo e fatores de qualidade dos ovos, unidade Haugh, espessura de casca, resistência à quebra, pigmentação de gema, gravidade específica) de poedeiras comerciais leves e semipesadas de 24 a 40 semanas de idade. Em cada experimento, foram utilizadas 240 poedeiras comerciais distribuídas em delineamento inteiramente casualisado com 8 aves por unidade experimental com 10 repetições. Os níveis dos aminoácidos, treonina, triptofano e valina foram mantidos os mesmos em todos os tratamentos através da suplementação de aminoácidos sintéticos. No primeiro e segundo experimentos avaliaram-se três níveis de proteína bruta (15,4%, 16,4% e 17,4%) em dietas para aves leves (experimento I) e aves semipesadas (experimento II) das linhagens Bovans White e Bovans Brown, respectivamente. No experimento I não foram observadas diferenças estatísticas para os parâmetros relacionados à qualidade da casca do ovo, nem mesmo para altura de albúmen e peso do ovo. A redução do nível proteico da dieta para 16,4% não afetou o desempenho das poedeiras leves (P<0,05). No experimento II, não houve diferenças estatísticas para os parâmetros avaliados. Nos experimentos III e IV avaliou-se o efeito de dois níveis de proteína bruta (16,4% e 17,4%) e dois níveis metionina+cistina (0,66% e 0,77) em dietas para aves leves (experimento III) e aves semipesadas (experimento IV) das linhagens Bovans White e Bovans Brown. No experimento III a qualidade de ovo não foi influenciada pelos tratamentos. Houve interação entre os níveis de proteína bruta e aminoácidos sulfurados para as variáveis de produção de ovos, consumo de ração e conversão alimentar por dúzia de ovos. As aves alimentadas com a dieta com 15,4% de proteína bruta apresentaram menor produção de ovos quando comparado às aves que receberam dietas com níveis de AAST elevados e com PB elevada. As aves alimentadas com 17,4% de PB e 0,77% de aminoácidos sulfurados apresentaram maior consumo e pior conversão alimentar (P<0,05). O aumento no nível de AAST resultou em maior peso do ovo. No experimento IV houve interação entre os fatores estudados, sendo que as aves alimentadas com níveis mais baixos de PB e AAST (16,4% e 0,66%, respectivamente), apresentaram menor produção de ovos e pior conversão alimentar. Para a variável peso de ovos, houve efeito dos níveis de AAST, sendo que as aves alimentadas com 0.77% produziram ovos com maior peso (P<0,05). / The study consisted of four experiments to evaluate the effect of protein and reduced levels of methionine+cystine on the performance and egg quality (egg production, feed intake, feed conversion, egg weight and egg quality factors, Haugh unit, shell thickness, breaking strength, yolk pigmentation) of light and semi heavy weight laying hens with 24-40 weeks of age. In each experiment 240 laying hens were distributed in a completely randomized design with 8 birds per experimental unit with 10 replicates. Levels of, threonine, tryptophan and valine were kept the same in all treatments by supplementation of synthetic aminoacid. In experiments I and II were evaluated three levels of crude protein (15.4%, 16.4% and 17.4 %) on diets for light Bovans White hens (experiment I) and Bovans Brown semi heavy weight (experiment II). In the first experiment there was no statistical differences in the parameters related to the quality of the egg shell, even for albumen height and egg weight were observed. The reduction of the protein level of the diet to 16.4% did not affect the performance of laying hens (P<0.05). In experiment II there were no statistical differences in the parameters evaluated. In experiments III and IV evaluated the effect of two levels of crude protein (16.4% and 17.4%) and two methionine + cystine levels (0.66% and 0.77%) on diets for light Bovans White hens (experiment III) and Bovans Brown semi heavy weight (experiment IV). In experiment III the egg quality was not affected by treatments. There was interaction between the levels of crude protein and sulfur aminoacids for the variables of egg production, feed intake and feed conversion per dozen eggs. Hens fed diets with lower protein levels had lower egg production when compared to hens fed diets with high levels of TSAA and high CP. Hens fed with diets with 17.4% of CP and 0.77% of sulfur aminoacids had higher intake and worse feed conversion (P<0.05). The increase in the level of TSAA resulted in higher egg weight. In experiment IV there was interaction between the factors studied, where lower levels of CP and TSAA (16.4% and 0.66 %, respectively), had lower egg production and lower feed conversion. For egg weight, there was effect of TSAA. Hens fed diets with 0.77% of TSAA produced heavier eggs (P<0.05).

Production, egg quality, behaviour, and physical condition were compared from Wk 20 to Wk 50 among three beak- trimmed commercial laying strains, Lohmann White (LW), H & N White (HN), Lohmann Brown (LB), and a non-commercial Cross between Rhode Island Red (male) and Barred Plymouth Rock (female) in conventional cages and in floor pens. All chicks were reared in their respective environments, and 450 and 432 pullets were housed at 18 and 7 weeks of age in cages and floor pens respectively. Hens in cages were provided with 688 cm2/bird and those in pens with over 6,000 cm2/bird, both of which are more than provided by commercial standards. Body weights and eggshell weights were higher for birds in floor pens than those in cages, and although they increased with age, body weight of hens in cages decreased at Wk 50. White-egg layers (LW, HN) used perches and nest boxes more than Brown-egg layers (LB, Cross). During the laying period, mortality was higher for all strains in cages and during the rearing period mortality was higher in floor pens for LB hens but not other strains. No aggressive behaviours were found, but the frequency of gentle feather pecking and pecking at the enclosure was higher in cages than in floor pens. Feather condition deteriorated over time in cages mainly because of contact with the cage wires whereas in floor pens, feather condition of birds at Wk 20 was not different from that at Wk 50. The frequency of keel bone deformities was higher for White-egg layers than for Brown-egg layers in cages and was higher for Cross hens than other strains in floor pens. Claws were longer in cages than in the floor pens. Foot condition was worse in floor pens than in cages. The welfare indicators used in this study showed that cages restricted the hens' behaviour compared to floor pens and resulted in higher laying period mortality, reduced body weight and deteriorated feather condition than floor pens. Both systems had advantages and disadvantages in regard to the hens’ health and welfare. The use of environmental complexities was strain specific in floor pens. The environment by genotype interactions suggests that the strain should be considered when considering alternative housing systems. / Land and Food Systems, Faculty of / Graduate

Das Ziel kontinuierlicher Messungen über zwei Jahre war die Bewertung der Stickstoffdepositionen und Ammoniakimmissionen einer Bodenhaltung (Voliere) mit Auslauf für 20.000 Hennen auf das Umfeld. Untersucht wurden weiterhin die Staub- und Geruchskonzentrationen in Stall- und Abluft. Die untersuchte Bodenhaltung emittiert im Jahr 41 g Ammoniak je Tierplatz. Die Vergleiche 14-tägiger Messdatenreihen zeigen, dass Emissionsmessungen an Tierhaltungen in möglichst langen Zeitfenstern und mindestens viermal jährlich durchzuführen sind. Die Immissionswerte für Ammoniak sind 40 m vom Stall am höchsten und erreichen nach ca. 350 m wieder das Hintergrundniveau am Standort. Unter Abzug der nicht dem Stall zuzurechnenden Hintergrundkonzentrationen verursacht der Stall im Nahbereich (40 m) eine Stickstoffdeposition von 18 kg/ha. Ab 230 m Distanz werden nur noch ca. 3 kg/ha deponiert. Die mittlere Tageskonzentration der Staubgehalte im Abluftstrom wurde in Abhängigkeit vom Außenklima zwischen 1,2 und 9,0 mg/m³ ermittelt. Der Anteil von PM-10 und PM-2.5 am Gesamtstaub betrug 80 bzw. 30 %. Für Gesamtstaub wurde ein Emissionsfaktor von 145,4 g/Tpl. zur Berechnung der Jahresemissionen ermittelt. Die in den Außenklimabereichen ermittelten Geruchsstoffkonzentrationen (Geruchsschwelle) im Abluftstrom liegen zwischen 25 und 115 GE/m³. Die mittleren Referenzwerte der Außenluft liegen bei 19 GE.

In zwei Legehennenställen mit den Volieresystemen Natura 60 und High Rise 3 wurden Stallklima und Emissionen untersucht. Die ermittelten Kenndaten wie Lufttemperatur und -feuchte, Stallstaub, Luftkeime und Geruch sowohl im Stallraum als auch im Abluftstrom wurden mit vorliegenden Kenndaten anderer Volieresysteme verglichen. Die untersuchten Haltungssysteme unterscheiden sich in den Ammoniakemissionen (88 bzw. 32 g/Tierplatz und Jahr). Die Messwerte liegen am unteren bzw. oberen Rand vergleichbarer Messungen anderer Volieresysteme. Die Untersuchungen belegen, dass häufig durchgeführte Kotbandentleerungen die Emissionen mindern. Die Staubbelastung der Abluft (66 bzw. 47 g/Tierplatz und Jahr) war im Vergleich zu anderen Volieresystemen (146 g/Tierplatz und Jahr) deutlich gemindert. Der Effekt ist konstruktionsbedingt und wird auf die treppenhausartige Anordnung der Volieren und das dadurch veränderte Bewegungsverhalten der Legehennen zurückgeführt. Die Untersuchungsergebnisse lassen einen deutlichen Einfluss der Abluftstromführung erkennen. Die ermittelten Geruchsemissionen (9 bzw. 24 GE/GV*s) sind differenziert und ordnen sich in den bisherigen Kenndatenbereich für Volierenhaltungen ein.

The aim of this work was to investigate the effects of feather availability and imprinting to loose feathers in the litter on the incidence of feather pecking behaviour (FP), condition of the integument and fear reactions in two genotypes of laying hens. Hens that were deprived from loose feathers in the litter (feathers were collected 4 times/week) exhibited a significantly less rate of feather pecking, less number of severe FP and showed a better feather score in the laying period compared to the control groups (no feather treatment) in both Lohmann Tradition (LT) & Lohmann Silver (LS) genotypes. Addition of brown feathers to the floor in LT hens (feathers were added once/week) was associated with a reduction in feather pecking rate, the severe form of this behaviour and improved plumage and skin conditions. Contrary, the addition of white feathers to the floor in LS was associated with the highest rate of feather pecking, the highest severe form of this behaviour as well as the worst feather and skin conditions in the laying period compared to other groups of the same genotype. The LT birds in all feather treatments had a better feather cover than the LS birds. Hens that were imprinted to loose feathers in the litter in the rearing period exhibited a higher rate of FP, higher number of severe FP and showed the worst feather and skin conditions when feathers were collected from the floor during the laying period. Also, these hens reacted more fearful during the tonic immobility test. It is concluded that loose feathers may play a role in the development of feather pecking behaviour in laying hens. Large differences between genotypes were found in respect to the availability of loose feathers, feather pecking and plumage and integument condition. Imprinting of chicks to loose feathers from the floor may affect the incidence of feather pecking later on. Ziel dieser Arbeit war es, die Einflüsse des Federangebotes und der Prägung auf lose Federn in der Einstreu auf die Häufigkeit des Auftretens von Federpicken (FP), den Zustand des Integuments und die Furchtreaktionen an zwei Legehennengenotypen zu untersuchen. Hühnern beider untersuchter Genotypen (Lohmann Tradition (LT) und Lohmann Silber (LS)), denen die losen Federn 4 mal/ Woche aus der Einstreu abgesammelt wurden, zeigten eine geringere Federpickrate, eine geringere Anzahl der schweren Form des FP und eine bessere Gefiederbeschaffenheit in der Legeperiode verglichen mit der Kontrollgruppe (keine Federbehandlung). Das Hinzufügen brauner Federn zur Einstreu bewirkte bei LT Hennen eine Reduktion der FP-Rate, der schweren Form des Federpickens und verbesserte die Gefieder- und Hautbeschaffenheit. Dagegen führte das Hinzufügen weißer Federn in die Einstreu während der Legeperiode bei LS Hennen zur höchsten Federpickrate und Anzahl der schweren Form des Federpickens sowie zur schlechtesten Gefieder- und Hautbeschaffenheit im Vergleich zu anderen Gruppen des gleichen Genotyps. Hühner der LT Linie wiesen in allen Federbehandlungen eine bessere Befiederung als die LS Hühner auf. Hennen, die während der Aufzuchtsperiode auf lose Federn in der Einstreu geprägt wurden, zeigten nach Absammeln der Federn während der Legeperiode eine erhöhte FP-Rate mit einer erhöhten Anzahl der schweren Form des FP und die schlechteste Gefieder- und Hautbeschaffenheit. Außerdem reagierten diese Hühner ängstlicher während des Tests auf tonische Immobilität. Es kann geschlussfolgert werden, dass lose Federn in der Einstreu eine Rolle bei der Entwicklung des Federpickverhaltens von Legehennen spielen und dass Federpicken als Futtersuchverhalten interpretiert werden kann. Grosse Unterschiede zwischen den Genotypen bestanden hinsichtlich der Verfügbarkeit von losen Federn in der Einstreu, des Federpickens sowie der Gefieder- und Integumentbeschaffenheit. Eine Prägung der Junghennen auf lose Federn in der Einstreu könnte das Auftreten von Federpicken zu einem späteren Zeitpunkt beeinflussen.

The objective of this study was to investigate the role of fine (F) and coarse (C) limestone ratios and exogenous phytase at standard and superdosing activity on performance, egg quality, and bone quality of post-peak and late-lay Hy-Line W-36 hens. For post-peak, treatments with 40F:60C at 0 and 400 FTU/kg (standard phytase activity) increased hen-day egg production (HDEP). Treatments with 15F:85C decreased feed intake (FI) but also increased unsaleable eggs (UE) and eggshell-breaking strength (EBS). Treatments with 0 and 400 FTU/kg increased albumen quality and treatments with 1500 FTU/kg increased bone quality and phytate breakdown. For late-lay, interaction effects of limestone and phytase were observed for FI, HDEP, UE, bone, and egg quality. Treatments with 40F:60C decreased UE and increased EBS and bone mineral content of aluminum (Al). Treatments with 0 FTU/kg increased eggshell proximate of phosphorus (P) and gizzard pH, but 400 and 1500 FTU/kg increased phytate breakdown and bone quality.

Conventional housing environments for broiler chickens and commercial laying hens are often barren, high-density environments with an emphasis on production efficiency. These housing conditions limit birds' ability to display species-specific behaviors, can negatively impact health, and may contribute to negative cumulative experience. Cumulative experience is the culmination of all positive and negative experienced during an animal's lifetime. However, cumulative experience is difficult to quantify, as no validated measures of cumulative experience exist. Additionally, existing measures of negative animal experience mostly rely on interpretations of animal behavior which can be subjective, time consuming, and difficult to interpret. Therefore, there is scientific need for objective measures that can detect cumulative experience in poultry. Secretory and plasma Immunoglobulin A (IgA), telomere length, feather corticosterone concentrations, and attention bias testing all seem to respond to positive and negative experiences in humans or other non-human animal species, indicating that they may be useful as measures for poultry. Therefore, the objective of this thesis was to determine if these novel measures could be used as indicators of cumulative experience in broiler chickens and laying hens. In chapter 3, secretory and plasma IgA concentrations were measured in broilers raised in either high-complexity or low-complexity environments under either high or low stocking density over three replicated experiments. Birds housed in highly complex environments showed higher concentrations of plasma IgA compared to birds housed in low-complexity environments at day 48 of age, indicating reduced chronic stress in the former. Additionally, day 48 secretory IgA concentrations were decreased in birds housed in high-density environments compared to birds housed in low density environments, indicating birds from high-density environments were more chronically stressed. In chapter 4, gonad and kidney telomere length was measured to determine cumulative experience in broilers raised in the same housing conditions and replicated experiments of chapter 3. Treatment did not impact gonad telomere length, in line with expectations as gonads contain stem cells which produce high concentrations of telomerase. Birds housed in high-complexity pens had longer kidney telomeres compared to birds in low-complexity pens, indicating high-complexity birds had more positive cumulative experience. Stocking density did not impact kidney telomere length. In chapter 5, attention bias, tonic immobility, plasma and secretory IgA concentrations, and feather corticosterone concentrations were determined in laying hens raised in conventional cages or enriched floor pens. Birds in enriched floor pens showed increased attention bias, decreased tonic immobility, increased secretory IgA concentrations at week 22 of age, and decreased feather corticosterone concentrations compared to caged hens. These results indicate that compared to conventional cages, enriched pens in this study improved immune systems, reduced chronic stress, reduced fear, but increased anxiety in hens. In conclusion, secretory and plasma IgA and telomere length show appropriate contrast in response to broiler chicken housing conditions. However, additional work needs to be done before these measures can be widely used as measures of cumulative experience in poultry. Furthermore, attention bias, secretory IgA, and feather corticosterone showed an appropriate contrast between chronic stress responses in laying hens, but confirmation is needed in other contexts. Overall, the results indicate a beneficial relationship between environmental complexity and poultry welfare physiology and affective state, with the exception for anxiety in laying hens. Thus, providing an enriched environment can improve the welfare of commercial poultry and result in positive cumulative experience in most situations. Additionally, these results indicate that stocking density is a negative environment in broilers but potentially less intense than previously thought under experimental conditions. The assessment of behavioral and physiological measures of cumulative and positive animal experience should be included in experiments seeking to determine the impacts of environmental or management conditions to determine the broader impacts on poultry welfare. / Doctor of Philosophy / Conventional housing systems of broiler chickens (raised for meat) and laying hens (raised for egg production) can negatively impact their welfare. Animal welfare, defined as an animal's ability to interact with and cope with their environment, is an individual experience for each animal and fluctuates on a scale from very negative to very positive. Traditionally, measurements of animal welfare have focused only on avoiding the negative aspects of animal welfare such as fear, distress (negative stress), hunger, thirst, pain, and suffering. However, it is important that animals are provided opportunities to experience positive animal welfare to provide a life worth living. So, when measuring animal welfare, all positive and negative experiences (termed cumulative experience) should be included to form an accurate picture of an animal's welfare. However, no validated measures of cumulative experience exist in non-human animals. However, recently, several potential measures of cumulative experience have been proposed in human and non-human animals including secretory and plasma IgA, telomere length, feather corticosterone, and attention bias testing. So, the objective of this thesis was to determine if these proposed measures can be used to determine cumulative experience in commercial broilers and laying hens. In chapters 3 and 4, we investigated if secretory and plasma IgA concentrations (measure of chronic stress; chapter 3) and telomere length (measure of cumulative experience; chapter 4) responded to environmental complexity (positive stimulus) and stocking density (negative stimulus) over three replicated experiments. Broilers were housed in a 2 × 2 factorial study of either high or low complexity or high or low density. This resulted in four treatment groups of high-complexity/high-density, low-complexity/low-density, high-complexity/low-density, and low-complexity/high-density. During chapter 3, environmental complexity increased concentrations of plasma IgA, indicating that birds from high-complexity pens were under less chronic stress compared to birds from low-complexity pens. Alternatively, high density decreased secretory IgA, indicating that birds from high-density pens were under a more chronic stress than birds from low density pens. In chapter 4, environmental complexity increased telomere length in broilers compared to low-complexity pens indicating that environmental complexity positively impacted cumulative experience. However, stocking density did not impact telomere length, indicating that high density did not negatively impact cumulative experience. In chapter 5, we investigated if attention bias (measure of anxiety), tonic immobility duration (measure of fear), plasma and secretory IgA (chronic stress), and feather corticosterone (chronic stress) responded to environmentally enriched floor pens (positive housing system) and conventional caging (negative housing system). We found that birds housed in enriched floor pens were more anxious (increased attention bias), less fearful (decreased tonic immobility duration), and less chronically stressed (increased SIgA concentrations at week 22 and increased feather corticosterone concentrations) compared to birds housed in conventional cages. Overall, IgA concentrations and telomere length (broilers) and attention bias, secretory IgA concentration, and feather corticosterone concentrations (layers) seem useable as measures of animal experience in commercial poultry. Additionally, these results indicate that positive experience has a positive impact on cumulative experience in commercial poultry. Stocking density also seems to contribute to chronic stress in broilers, indicated by decreased SIgA concentrations, but only during the last few weeks of life. These findings should be confirmed by additional studies before common use as measures of cumulative experience in animals. However, the inclusion of measures of cumulative and positive animal experience should be included in experiment which wish to determine the broad impacts of housing system on non-human animals.

O bem-estar animal pode influenciar o sistema produtivo na avicultura de postura. Sendo assim, o sistema free-range ou \"ao ar livre\" sem o uso de antibióticos surge como uma alternativa aos sistemas confinados. Espera-se que esse sistema torne-se cada vez mais difundido em atenção à demanda do mercado consumidor e bem-estar animal. Neste estudo, são abordados à influência da ambiência nas características qualitativas da cama aviária e ninhos, qualidade do ar, padrões fisiológicos e comportamentais, e avaliação da microbiota intestinal de galinhas poedeiras criadas no sistema free-range sem o uso de antibióticos. O estudo foi conduzido em um galpão comercial de galinhas poedeiras da linhagem Lohmann Brown. O período experimental correspondeu da 18ª a 24ª semanas de idade, para as avaliações relacionadas à ambiência, parâmetros fisiológicos e comportamentais. Para a estimativa da densidade bacteriana intestinal, as aves foram avaliadas durante o período de produção dos ovos, correspondendo à idade de pré-pico de postura (13ª semana), pico de postura (24ª semana) e pós-pico de postura (63ª semana). Água e ração foram fornecidas ad libitum. Constatou-se que as condições climáticas foram favoráveis, ou seja, as aves permanceram dentro da zona de termoneutralidade e na faixa de conforto térmico ideal. Resultados referentes à amônia volatilizada foram satisfatórios, assim como a umidade da cama e ninhos. Não houve incidência de pododermatite e as condições de empenamento das aves permaneceram íntegras nas regiões avaliadas. As avaliações comportamentais das aves demonstrou que as mesmas estavam em totais condições de bem-estar animal, ademais os níveis de corticosterona foram significativamente inferiores. Em relação ao estudo da microbiota intestinal das aves, as análises revelaram diferentes padrões de densidade dos simbiontes em relação às regiões estudas. A população das bactérias benéficas foi significativamente maior em comparação as bactérias patogênicas. Os simbiontes intestinais estudados demonstraram crescimento diferencial ao longo do período estudo. Diante do exposto, podemos reportar que o sistema free-range sem o uso de antibióticos apresentou qualidade de vida às aves poedeiras no que tange o bem-estar animal. / Animal welfare quality may affect egg laying livestock. Thus, the antibiotics-free free-range rearing system (AFFRS) came to light as an alternative to conventional production systems. Furthermore, it is expected AFFRS become more and more widespread as a response to consumer demand and animal welfare rules. In here, we aimed to evaluate the influence of the ambiance on the avian litter and nests, air quality, bird physiology and behavioral patterns, and their intestinal microbiota as well. The study was carried out using Lohmann Brown laying hens breed of the 18th to the 24th weeks-old kept in a commercial shed, and the environmental, physiological and behavioral parameters were evaluated. Additionally, gut microbiota was estimated by using hens of three different egg production cycles. The first cycle was represented by grower hens with 13th weeks of age as their reproductive organs were developing (i.e. early cycle), followed by 24th weeks-old grower hens (high egg production cycle), and 63th weeks-old grower cycle hens (late egg-laying cycle). Water and feed were supplied ad libitum. Data demonstrated birds were in optimal thermal comfort and the volatilized ammonia concentration remained at very low rates, as well as the bed and nest moisture levels. There was no incidence of pododermatitis and the conditions of feathering of the birds remained intact. Animal welfare conditions were optimal as demonstrated through behavioral data and corticosterone levels. Furthermore, gut microbiota densities were different between target symbiont-groups of the same gut region and among different gut segments investigated. Beneficial bacteria densities were significantly higher than pathogenic bacteria and gut symbionts showed differential growth curve throughout the studied period. Thus, our results demonstrated that the AFFRS met the laying hen\'s welfare quality rules and can be considered a good alternative rearing system to the egg production industry.

In einer klinisch-prospektiven Feldstudie wurden Legehennenherden untersucht, in denen poldefekte Eier auftraten. Aus 3 betroffenen Herden wurden hierzu gezielt 86 Hühner, die poldefekte Eier legten, sowie willkürlich 72 Hühner, die normale Eier legten, untersucht. Alle Herden zeigten eine gute Legeleistung und eine hohen Sekundaanteil von über 5% an der Legeleistung, wobei die verschmutzten Eier die größte Fraktion ausmachten. Je mehr poldefekte Eier auftraten, umso höher waren der Schmutzeianteil sowie der Anteil an Bruch- und Fließeiern. Dieses Phänomen lässt sich durch die verringerte Schalenstabilität der poldefekten Eier erklären. Bei den auf poldefekte Eier selektierten Hühnern machten die poldefekten Eier den Hauptanteil der absoluten Legeleistung mit 46 bis 64% aus, sie hatten zudem einen Bruch- und Fließeianteil zwischen 27 und 38%. Der Bruch –und Fließeianteil hat die absolute Legeleistung gesenkt, aufgrund ihrer Instabilität gingen viele dieser Eier auf dem Weg vom Huhn zur Packstelle verloren. Hatte ein Huhn einmal begonnen poldefekte Eier zu legen, legte es fast keine normalen Eier mehr. In der serologischen Untersuchung mittels ELISA hatten die Hühner aller drei Herden, welche poldefekte Eier legten, einen signifikant höheren Antikörpertiter (p<0,05) gegen Mycoplasma synoviae (MS) im Vergleich zu der Kontrollgruppe. Bei allen Hühnern konnte MS-spezifische DNA in Trachealabstrichen mittels PCR amplifiziert werden. Kloakenabstriche erwiesen sich mittels MS-PCR bei den Hühnern mit poldefekten Eiern zu 87% (n=72), bei den Kontrollhühner dagegen nur zu 18% (n=13) als MS positiv. MS war darüber hinaus aus Legedarmabstrichen von fünf Hühnern, welche poldefekte Eier legten, kultivierbar. Darüber hinaus wurden 49 poldefekte Eier und 43 Eier ohne Poldefekte im Eiklar auf MS untersucht. Bei fast allen poldefekten Eiern konnte im Eiklar MS-spezifische DNA nachgewiesen werden (n=48; 98%), im Unterschied zu den Kontrolleiern (n=11; 26%). Ein kausal-pathogenetischer Zusammenhang zwischen einer Infektion des Legedarms mit MS und dem Legen von Eiern mit Poldefekten ist den Ergebnissen folgend wahrscheinlich, wobei verschiedene Faktoren für die Infektion des Legedarms verantwortlich zu sein scheinen. Bei der qualitativen Untersuchung hatten die poldefekten Eier eine signifikant (p<0.05) geringere Schalenstabilität im Vergleich zu den Kontrolleiern. Die Eischalenspitzen der Gruppe „Pol A“ hielten mit 11,4N fast nur ein Viertel der Belastung der Referenzherde aus. Die hohe Schalenstabilität der Kontrolleier von über 40N zeigte, dass die Legehennen, die keine poldefekten Eier legten, keine Schalenstabilitätsprobleme hatten. Die Farbe der braunen poldefekten Eier war oft signifikant heller als die der Kontrolleier, auch waren die Farbpigmente (a- und b-Wert) signifikant (p<0,05) verändert. Das trockene Schalengewicht war bei den poldefekten Eiern mit bis zu einem Gramm Unterschied pro Ei signifikant (p<0,05) niedriger als bei den Kontrolleiern. Elektronenmikroskopische Untersuchungen der Eischale wurden an 2 poldefekten Eiern und 2 Eiern ohne Poldefekte durchgeführt. Es konnte gezeigt werden, dass sich die poldefekten Eier sowohl in Struktur als auch im Durchmesser der Eischale erheblich von den Kontrolleiern unterschieden. Es ist fraglich, ob die veränderte Schale der poldefekten Eier in ihrer mikrobiologischen Barrierefunktion beeinträchtigt ist. Die für die Eifrische relevanten Größen wichen bei den poldefekten Eiern teilweise signifikant von den Kontrolleiern ab. In den braunen poldefekten Eiern traten vermehrt Fleischflecken auf. Aus den poldefekten Eiern ließ sich der Erreger MS jedoch nicht isolieren und anzüchten. Die untersuchten poldefekten Eier erfüllten damit - soweit ihre Schale intakt war - die formalen Anforderungen an frische Eier der Güteklasse A nach VO (EG) Nr. 1234/2007 und 598/2008. In der gelelektrophoretischen Analyse der organischen Matrix der Eischalen war in den poldefekten Eiern die Intensität der Lysozym zugeordneten Bande jeweils höher als in den Kontrolleiern, dies ließ sich jedoch statistisch nicht untermauern. Ätiologisch ist denkbar, dass eine subklinische bakterielle Besiedlung des Legedarms mit MS und die daraus resultierende Immunantwort den Lysozymspiegel des Uterussekrets erhöht. Die Verschiebung des Lysozymspiegels wirkt sich sowohl qualitativ als auch quantitativ negativ auf die Eischalenbildung aus. Das Resultat ist eine verringerte Schalenstabilität, das morphologische Korrelat der im Eischalenspitzenbereich sichtbare Defekt. / Hens laying eggs with egg-pole shell defects (EPS) were examined in a clinical prospective study. 86 hens with EPS and 72 hens without EPS from 3 flocks were selected for this study. All examined flocks showed a good laying performance, although laying many eggs off quality class B. The rate was over 5 percent of all laid eggs, most of them were dirty eggs. There was a significant correlation between EPS-eggs and dirty eggs, although between EPS-eggs and broken- and thin shelled eggs. This phenomenon could be explained by the decreased eggshell strength of the EPS-eggs. The selected hens with EPS showed a rate between 46 and 64 percent EPS-eggs of all laid eggs, the rate of broken- and thin shelled eggs was between 27 and 38 percent. Those broken- and thin shelled eggs increased absolute laying performance, because of their instability many of them were lost on the way from the cage to the packing station. The selected hens with EPS produced almost no normal eggs. It could be shown that if a hen starts laying EPS-eggs, she is almost unable to lay normal eggs any more. It could be proven serologically that hens with EPS had significant (p<0.05) higher titers against Mycoplasma synoviae (MS) then hens without EPS. MS-DNA was detectable from the tracheal swab in all tested hens. PCR tested cloacal swabs for MS were more frequently positive from hens with EPS (n=72; 87%) then from hens without EPS (n=13; 18%). Furthermore MS could be cultivated from the oviduct of 5 hens with EPS. Additionally 49 Eggs with EPS and 43 Eggs without EPS were examined microbiologically. MS-DNA was detectable in the albumen of nearly all eggs with EPS (n = 48; 98 %), contrary to the eggs without EPS (n = 11; 26%). Due to the findings it is very likely that an infection of the oviduct with MS results in eggs with EPS, whereas different factors may play an important role for the infection of the oviduct. In the qualitative investigation EPS-eggs had a significant (p<0.05) decreased pole eggshell strength than the eggs without EPS. The pole eggshell strength of the EPS-eggs of flock A (group “Pol A”) was with 11,4N just about a quarter of the pole eggshell strength of the reference flock. Nearly all eggs without EPS had a pole eggshell strength over 40N. It could be shown that hens without EPS had no decreased eggshell strength. The color of the brown EPS-eggs was often significant brighter than color of brown eggs without EPS. Furthermore the color pigments of the EPS-eggs were significant (p<0.05) changed. Dry eggshell weight was in EPS-eggs up until 1 gram difference significant (p<0.05) lower compared to eggs without EPS. Scanning electron microscopy was performed in 2 eggs with EPS and 2 eggs without EPS. This investigation revealed that eggs with EPS showed considerable differences of the eggshell structure as well as the cross section dimension according to eggs without EPS. It is doubtful whether the changed eggshell of EPS-eggs is impaired in its microbiological barrier function. The relevant variables for the freshness of the egg varied in the EPS-eggs in some cases significantly (p<0.05) compared to the control eggs. In Brown EPS-eggs increased Meat-spots occurred. However, MS could not be cultivated from EPS-eggs. Therewith fulfilled the investigated EPS-eggs - if their shell was intact - the formal requirements for fresh eggs of grade A eggs under regulation VO (EG) No. 1234/2007 and 598/2008. A gel electrophoretic analysis of the organic matrix of the eggshells of EPS-eggs and normal eggs was made. Intensity of the lysozyme-associated band was in the EPS eggs respectively higher than in the control eggs. However, this could not be proven statistically. Etiologically is conceivable that subclinical bacterial colonization of the hens oviduct with MS and the resulting immune response increases the lysozyme level in the uterine secretions. The shift of the lysozyme level affects both quantitatively and qualitatively negative on the eggshell formation. The result is a decrease in shell strength. The morphological correlate is the visible eggshell pole defect.

Made available in DSpace on 2014-06-11T19:32:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-10Bitstream added on 2014-06-13T20:44:09Z : No. of bitstreams: 1 buchala_fg_dr_jabo.pdf: 2239800 bytes, checksum: 45318e9bad370d2fed0afb87b5d25d4f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A suspeita de Laringotraqueíte Infecciosa Aviária (LTI) em galinhas de postura de ovos comerciais da região de Bastos, Estado de São Paulo, foi notificada em 27/12/2002 ao Serviço de Defesa Sanitária Animal. A Coordenadoria de Defesa Agropecuária instituiu um programa de saúde animal para o controle da doença, com base no planejamento de fases que foram implantadas durante o seu desenvolvimento e amparadas por instrumentos legais especificamente elaborados para esta finalidade. A Portaria CDA no 2, de 10 de janeiro de 2003, proibiu o trânsito interestadual de aves de descarte da região e deu início à fase preparatória. A Resolução SAA no 27, de 30 de setembro de 2003, caracterizou a fase de execução com a delimitação da área infectada, denominada “Bolsão” de Bastos. A Portaria CDA no 4, de 20 de janeiro de 2004, estabeleceu um programa compulsório de vacinação contra a LTI. A partir de junho de 2004, nenhum novo caso de LTI foi observado no “Bolsão”. A Resolução SAA no 43, de 17 de novembro de 2005, declarou a LTI controlada com vacinação, dando início à fase de consolidação das medidas de profilaxia implantadas. Com a Resolução SAA no 55, de 20 de dezembro de 2006, e a Portaria CDA no 58, de 29 de dezembro de 2006, o programa evoluiu para a fase de manutenção. Todas as fases foram complementadas por medidas de biosseguridade implantadas pelos avicultores. / A suspect of Avian Infectious Laryngotracheitis (ILT) in layer hens from Bastos region, São Paulo State, was communicated on December 27, 2002, to the Official Service of Animal Health. The Coordenadoria de Defesa Agropecuária (CDA) instituted an animal health program for the control of the disease, based on the planning of phases established during the development of the program and supported by legal instruments especially developed for this aim. The Portaria CDA Nº 2 on January 10, 2003 forbade interstate traffic of adult layer poultry from the region and started the preparatory phase. The Resolução SAA no 27 on September 30, 2003, characterized the execution phase by the delimitation of the infectious zone identified as “Bolsão” of Bastos. The Portaria CDA no 4 on January 20, 2004, established a compulsory program of vaccination against ILT. From the month of June, 2004, no new case was observed in the “Bolsão”. The Resolução SAA no 43 on November 17, 2005, declared the ILT controlled with vaccination, and started the phase of consolidation of the implanted prophylactic measures. From the Resolução SAA no 55 on December 20, 2006, and the Portaria CDA no 58 on December 29, 2006, the program evolved to the phase of maintenance. All the phases were complemented by biosecurity measures implanted by the owners of the layer hens.