O presente experimento foi realizado no aviário da Faculdade de Medicina Veterinária e Zootecnia da Universidade Estadual Paulista do Campus de Botucatu. Foram utilizadas 288 aves da linhagem Hisex Brown, em produção, com 30 semanas de idade no início do experimento, divididas em nove tratamentos com quatro repetições cada, num esquema fatorial 3X3, sendo três níveis de energia metabolizável fornecidos por ave/dia (280, 300 e 320 kcal) e três diferentes consumos de óleo por ave/dia (0,00; 0.75 e 1,50 g). O consumo diário de ração foi restrito a 115, 110 e 105 g para obtenção dos níveis desejados de energia metabolizável e óleo. As rações foram balanceadas para que todas as aves recebessem diariamente 18 g de proteína bruta, 4,2 g de Cálcio, 0,66 g de Fósforo Total, 0,40 g de Metionina, 0,73 g de Metionina + Cistina e 0,83 g de Lisina. Não foi constatada diferença estatística (P>0,05) para produção (%), massa (g/ave/dia), peso médio (g) e gravidade específica dos ovos bem como para umidade, percentagem de gordura, proteína e cinzas do albume e da gema. Houve efeito do consumo diário de energia (P>0,05) sobre o peso final, ganho de peso e percentagem de gordura abdominal, havendo um aumento destes com o aumento da densidade energética. Foram constatadas pioras significativas, com efeito linear, na conversão alimentar por massa, na conversão alimentar por dúzia de ovos produzidos e conversão de energia, em função do aumento da energia consumida diariamente. Foram constatados efeitos significativos, com efeito quadrático na percentagem de casca em função do consumo diário de energia. Já para percentagem de gema e albume houve efeito linear em relação ao consumo de óleo, sendo que para o primeiro parâmetro houve aumento do mesmo com maior inclusão de óleo e, no outro, diminuição. Houve efeito significativo do consumo diário de óleo (P<0,05) e da interação consumo de energia e consumo de óleo (P<0,05) sobre Unidades Haugh. Houve efeito significativo da cor da gema em função do consumo diário de energia e óleo diários (P<0,05). / The present experiment was carried out at the experimental aviary of the Veterinary Medicine and Zootecny University - Botucatu. At the beginning of the experiment 288 semi -heavy Hisex Brown strain birds were used, in production, 30 weeks old, divided in nine treatments with four replications each, in a factorial arrangement 3X3, with three levels of metabolizable energy supplied per bird/day (280, 300 and 320 kcal) and three different oil consumptions for bird/day (0.00; 0.75 and 1.50 g). The birds had a restricted daily feed consumption of 115, 110 and 105 9 to obtain the levels of metabolizable energy and oi!. The diets were balanced so that ali of the experimental birds received 18 9 of crude protein daily, 4.2 9 of Calcium, 0.66 9 of Total Phosforus, 0.40 9 of Methionine, 0.73 9 of Methionine + Cistine and 0.83 9 of Cistine. The parameters of production (%), mass (g/bird/day), average weight (g) and specific gravity of the eggs where not humidity, fat percentage, protein and ash of the albumen and yolk didn \'t differ significantly different among the treatments. There was a significant effect of the daily consumption of energy on the final weight, weight gains and percentage of abdominal fat, which demonstrate an increase of these parameters with the increase of the energy density. Significant worsenings were verified (P < .05), with linear effect in the feed conversion for mass, in the feed conversion for dozen of produced eggs and conversion of energy, in function of the increase of the energy consumed daily. Significant effects were verified, with quadratic effect in the shell percentage in function of the daily consumption energy. However for yolk percentage and albumen there was a linear effect to oil consumption and for the first parameter there was an increase of that with larger oil inclusion and, in the other one, decreased. There was significant effect of daily consumption of oil (P < .05) and of the interaction consumption of energy and oiI consumption (P < .05) on Haugh Units. There was a significant effect of the color of the yolk in function to the daily consumption of energy and oil (P <.05).

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).

O presente experimento foi realizado no aviário da Faculdade de Medicina Veterinária e Zootecnia da Universidade Estadual Paulista do Campus de Botucatu. Foram utilizadas 288 aves da linhagem Hisex Brown, em produção, com 30 semanas de idade no início do experimento, divididas em nove tratamentos com quatro repetições cada, num esquema fatorial 3X3, sendo três níveis de energia metabolizável fornecidos por ave/dia (280, 300 e 320 kcal) e três diferentes consumos de óleo por ave/dia (0,00; 0.75 e 1,50 g). O consumo diário de ração foi restrito a 115, 110 e 105 g para obtenção dos níveis desejados de energia metabolizável e óleo. As rações foram balanceadas para que todas as aves recebessem diariamente 18 g de proteína bruta, 4,2 g de Cálcio, 0,66 g de Fósforo Total, 0,40 g de Metionina, 0,73 g de Metionina + Cistina e 0,83 g de Lisina. Não foi constatada diferença estatística (P>0,05) para produção (%), massa (g/ave/dia), peso médio (g) e gravidade específica dos ovos bem como para umidade, percentagem de gordura, proteína e cinzas do albume e da gema. Houve efeito do consumo diário de energia (P>0,05) sobre o peso final, ganho de peso e percentagem de gordura abdominal, havendo um aumento destes com o aumento da densidade energética. Foram constatadas pioras significativas, com efeito linear, na conversão alimentar por massa, na conversão alimentar por dúzia de ovos produzidos e conversão de energia, em função do aumento da energia consumida diariamente. Foram constatados efeitos significativos, com efeito quadrático na percentagem de casca em função do consumo diário de energia. Já para percentagem de gema e albume houve efeito linear em relação ao consumo de óleo, sendo que para o primeiro parâmetro houve aumento do mesmo com maior inclusão de óleo e, no outro, diminuição. Houve efeito significativo do consumo diário de óleo (P<0,05) e da interação consumo de energia e consumo de óleo (P<0,05) sobre Unidades Haugh. Houve efeito significativo da cor da gema em função do consumo diário de energia e óleo diários (P<0,05). / The present experiment was carried out at the experimental aviary of the Veterinary Medicine and Zootecny University - Botucatu. At the beginning of the experiment 288 semi -heavy Hisex Brown strain birds were used, in production, 30 weeks old, divided in nine treatments with four replications each, in a factorial arrangement 3X3, with three levels of metabolizable energy supplied per bird/day (280, 300 and 320 kcal) and three different oil consumptions for bird/day (0.00; 0.75 and 1.50 g). The birds had a restricted daily feed consumption of 115, 110 and 105 9 to obtain the levels of metabolizable energy and oi!. The diets were balanced so that ali of the experimental birds received 18 9 of crude protein daily, 4.2 9 of Calcium, 0.66 9 of Total Phosforus, 0.40 9 of Methionine, 0.73 9 of Methionine + Cistine and 0.83 9 of Cistine. The parameters of production (%), mass (g/bird/day), average weight (g) and specific gravity of the eggs where not humidity, fat percentage, protein and ash of the albumen and yolk didn \'t differ significantly different among the treatments. There was a significant effect of the daily consumption of energy on the final weight, weight gains and percentage of abdominal fat, which demonstrate an increase of these parameters with the increase of the energy density. Significant worsenings were verified (P < .05), with linear effect in the feed conversion for mass, in the feed conversion for dozen of produced eggs and conversion of energy, in function of the increase of the energy consumed daily. Significant effects were verified, with quadratic effect in the shell percentage in function of the daily consumption energy. However for yolk percentage and albumen there was a linear effect to oil consumption and for the first parameter there was an increase of that with larger oil inclusion and, in the other one, decreased. There was significant effect of daily consumption of oil (P < .05) and of the interaction consumption of energy and oiI consumption (P < .05) on Haugh Units. There was a significant effect of the color of the yolk in function to the daily consumption of energy and oil (P <.05).

Orientador: João Martins Pizauro Junior / Resumo: O desenvolvimento dos anfíbios é caracterizado por uma série de eventos que possibilitam a esses animais a ocupação dos ambientes aquático e terrestre. Nesse sentido, a supressão do sistema imunológico é necessária para que esses eventos ocorram de forma ordenada, evitando então, respostas autoimunes. Por outro lado essa imunossupressão durante a metamorfose pode tornar os animas mais susceptíveis a algumas doenças, dentre elas, a causada pelo fungo Batrachochytrium dendrobatidis (Bd), que é considerado o principal patógeno de anfíbios da atualidade. Nesse contexto, a produção de anticorpos da classe IgY anti-Bd, extraídos de gemas de ovos de galinhas poedeiras infectadas com o referido fungo, pode agregar valor ao ovo, auxiliar no combate a quitridiomicose, diminuição da perda da produção e dispersão do patógeno por criadouros, diminuindo também o uso de antibióticos no tratamento e profilaxia da quitridiomicose, aumentando o nível de segurança da carne e valorizando o produto final. No presente estudo a imunização das aves com o antígeno desativado fez com que o sistema humoral das mesmas respondesse a indução contra Bd viabilizando a produção e purificação de imunoglobulinas da classe IgY específicas e de alta avidez contra o fungo. A transferência passiva das imunoglobulinas purificadas das gemas apresentou resultados promissores, onde os girinos de rã-touro (Lithobates catesbeianus) tratados não apresentaram danos deletérios quanto à sanidade animal dos mesmos, mantendo ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of amphibians is characterized by a series of events that enable these animals to occupy aquatic and terrestrial environments. In this sense, suppression of the immune system is necessary for these events to occur in an orderly manner, avoiding autoimmune responses. On the other hand, this immunosuppression during metamorphosis may make the animals more susceptible to some diseases, among them, the one caused by the fungus Batrachochytrium dendrobatidis (Bd), which is considered the main amphibian pathogen today. In this context, the production of anti-Bd IgY class antibodies, extracted from egg yolks of laying hens infected with this fungus, may add value to the egg, assist in the fight against chytridiomycosis, decrease production loss and pathogen dispersion by breeding facilities, reduce the use of antibiotics in the treatment and prophylaxis of chytridiomycosis, increasing the safety level of the meat and valuing the final product. In the present study, the immunization of hens with the deactivated antigen caused their humoral system to respond to induction against Bd, enabling the production and purification of specific and highly avid fungal IgY class immunoglobulins. Passive transfer of purified immunoglobulins from yolk showed promising results, where treated bullfrog tadpoles (Lithobates catesbeianus) showed no deleterious damage to animal health, keeping the morphology and counting of blood cells within normal range. These results enable the develop... (Complete abstract click electronic access below) / Doutor

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.

Ziel dieser Arbeit war eine Untersuchung zur Häufigkeit des Wechsels von Legehennen zwischen Innen- und Außenbereichen, einschließlich der Aufenthaltsdauer außerhalb des Stalles, in Relation zum Federpicken und der Beschaffenheit des Integumentes. Der Einfluss der Haltungsbedingungen und der Einfluss des Genotyps wurden untersucht. Die Gruppe, die ohne Grünauslauf war, bewegte sich signifikant häufiger zwischen dem Stall und dem Wintergarten als andere Gruppen mit Grünauslauf. Die Aufenthaltsdauer im Stall und Wintergarten war in der Gruppe ohne Grünauslauf signifikant höher als bei anderen mit Grünauslauf (GA). Hennen, denen eine große Auslauffläche angeboten wurde (10m²/T) bewegten sich signifikant häufiger zu den Außenbereichen als andere mit einem Angebot von 2,5 m²/Tier. Hennen mit einem Angebot von 2,5 m²/Tier hielten sich länger auf dem Grünland auf als Hennen mit einer Besatzdichte von 10m²/T. Die höchsten Federpickaktivitäten waren in der Gruppe ohne GA im Vergleich zu den Gruppen mit GA. Im Vergleich zu anderen Gruppen mit GA, hatte die Gruppe ohne GA einen schlechteren Gefiederzustand. LSL Hennen bewegten sich im Vergleich zu den LT Hennen häufiger zwischen Innen- und Außenbereichen. LSL Hennen hielten sich im Vergleich zu den LT Hennen länger im Wintergarten auf. Dennoch hielten sich die LT Hennen im Vergleich länger auf dem Grünland auf. Die schlechteste Gefiederbeschaffenheit wiesen LSL Hennen im Vergleich zu LT Hennen auf. Die Resultate der vorliegenden Untersuchungen weisen darauf hin, dass die Auslaufnutzung einen positiven Einfluss auf den Gefieder- und Hautzustand hat. Die untersuchten Genotypen unterschieden sich in der Häufigkeit des Ortswechsels und der Aufenthaltsdauer im Grünauslauf. / The aim of this work was to investigate the frequency of movement of laying hens between indoor and outdoor enclosures and the time hens spent outside the hen house in relation to feather pecking and condition of the integument. The effect of housing condition and the genotype were studied. Hens that were offered a large space to outside open area (10m²/bird) moved significantly more frequently to the outdoor areas than others (2.5m²/bird). Frequency of movement between poultry house and winter garden was higher in the group without grassland. Hens kept at a higher density outdoors (2.5m²/bird) spent significantly more time in this area than hens were kept at a lower density (10m²/bird) on grassland. The high rates of feather pecking are observed in the group without grassland compared to groups stocked at 2.5m² or 10m² per bird on grassland The group without grassland had poorer feather condition compared to other groups that had 2.5m²/bird and 10m²/bird on grassland Lohmann Selected Leghorn (LSL) hens moved more frequently to the outdoor enclosures compared to Lohmann Tradition (LT). But LT hens spent significantly more time on grassland than LSL.The plumage condition was worse in LSL than LT hens. It is concluded that housing conditions might have a stronger influence on the development of feather pecking than the genetic aspect. Large differences between the genotypes examined were found in respect to the frequency of movement to the outdoor areas, the time spent outside and plumage and skin damage.

Das Ziel der vorliegenden Arbeit war es, die Eignung von vierzehn Pflanzenarten des Wirtschaftsgrünlands für die Etablierung von Grasnarben für die Hühnerfreilandhaltung zu untersuchen. Neun Gräser und fünf Kräuter, deren hohe Leistungsfähigkeit aus intensiv bewirtschafteten Systemen, und deren gute Schnitt-, Weide- und Trittverträglichkeit bekannt sind, wurden vergleichend bewertet. In einem Feldexperiment wurde die Verträglichkeit der Pflanzen gegenüber Beweidung mit Hühnern untersucht. Die Hypothese lautete, dass sich die Leistungsfähigkeit der Arten deutlich unterscheiden würde, da die Störung, die durch Beweidung mit Hühnern erzeugt wird, stärker und von anderer Natur ist als in anderen Bewirtschaftungssystemen. Monokulturen und eine Mischsaat der vierzehn Arten wurden einer Umtriebsbeweidung mit Legehennen in drei Stufen der Weidedauer unterzogen. Die Wirkung der Faktoren Pflanzenart, Weidedauer und Umtrieb auf Bodendeckung, Dichte der Triebe und Vegetationspunkte, und Wachstum der oberirdischen Biomasse wurde analysiert. Aus ersteren Zielgrößen wurde die Resistenz der Grasnarbe gegenüber der Beweidung abgeleitet, aus der dritten ihre Resilienz. Die Hypothese, dass sich die untersuchten Arten stark im Hinblick auf ihre Resistenz und Resilienz gegenüber Beweidung mit Hühnern unterscheiden würden, wurde bestätigt. Unsere Ergebnisse deuteten darauf hin, dass Gräser prinzipiell besser für die Bepflanzung von Auslaufflächen geeignet sind als Kräuter. Die Arten Festuca arundinacea und Poa supina zeigten mit einer Bodendeckung von über 80 %, einer konstanten Triebdichte und einer gleich bleibenden, vergleichsweise hohen Wachstumsrate von mehr als 4,8 g Trockenmasse m-2 d-1 die beste Leistungsfähigkeit bei wiederholter Beweidung und langer Weidedauer. In einem ergänzenden Gefäßversuch im Gewächshaus wurde untersucht, welche mit der Wuchsform in Zusammenhang stehenden Eigenschaften die Toleranz der Pflanzen gegenüber Beweidung mit Hühnern erklären. Die Hypothese bestand darin, dass die Biomasseallokation vor der Störung und die Lage von Speicherorganen und Knospen für klonales Wachstum die Schädigungstoleranz bestimmen würden; sie würde bei Arten hoch sein, bei denen diese Organe konzentriert an der Sprossbasis und unterhalb von oder nahe der Erdoberfläche liegen. Eine Auswahl der im Freilandversuch verwendeten Pflanzenarten, die drei Wuchsformen repräsentierte (Arten ohne Ausläufer; Arten mit Stolonen; Arten mit Rhizomen) wurde einer standardisierten mechanischen Schädigung in drei Intensitäten ausgesetzt, welche zugleich auf Spross und Wurzel wirkte. Die Ergebnisse dieses Versuchs zeigten, dass die Pflanzenart, nicht aber die Wuchsform die Toleranz gegenüber Schädigung bestimmten. Die höchste Toleranz wurde bei F. arundinacea und Poa pratensis festgestellt. Der Wiederaufwuchs oberirdischer Biomasse war über alle Arten und Intensitäten der Behandlung hinweg stark mit der relativen Wurzelbiomasse (der Wurzelbiomasse der behandelten Pflanze im Verhältnis zu der der Kontrollpflanze) korreliert, allerdings nicht mit der Wurzelbiomasse vor der Behandlung. Die Resistenz der Wurzel gegenüber mechanischer Schädigung ist daher offenbar eine wesentliche Determinante der Toleranz gegenüber der untersuchten Störung. Schließlich wurde der Einfluss von botanischer Zusammensetzung und Degradierung der Grasnarbe auf das Nahrungssuchverhalten der Hühner untersucht. In dem oben erläuterten Feldexperiment war die Häufigkeit der Verhaltensweisen Picken an Pflanzen, Picken am Boden und Scharren aufgezeichnet worden. Aus den Daten ging hervor, dass Pflanzenart und Degradierung der Grasnarbe das Nahrungssuchverhalten der Hühner signifikant beeinflussten. Eine steigende Weidedauer reduzierte die Bodendeckung grüner Vegetation signifikant; allerdings unterschieden sich die untersuchten Pflanzenarten deutlich im Hinblick auf das Ausmaß der Degradierung, die durch standardisierte Beweidungsdauer erzeugt wurde. Bei steigender Weidedauer und sinkender Bodendeckung grüner Vegetation war bei den meisten Pflanzenarten eine Abnahme der Häufigkeit des auf die Grasnarbe gerichteten Pickverhaltens (Picken an Boden und Pflanzenteilen summiert) nachweisbar. Dieses Ergebnis wird als bedeutsam für das Tierwohl erachtet, da in Umwelten, die wenig Anreiz zu Picken an Objekten bieten, die Gefahr besteht, dass die Tiere vermehrt Federpicken zeigen. Wir leiten aus diesen Ergebnissen ab, dass die Wahl von Pflanzenarten wie P. supina, die sowohl eine hohe Resistenz gegenüber der durch Beweidung verursachten Störung aufweisen, als auch einen starken Anreiz zu Nahrungssuchverhalten, und insbesondere zu Picken liefern, als Begrünung den Beitrag der Auslauffläche zu Tierwohl und –gesundheit fördern können. Zusammenfassend haben unsere Experimente gezeigt, dass die Wahl der Pflanzenart zur Auslaufbegrünung ein wichtiger Faktor zur Gewährleistung der Multifunktionalität der Grasnarbe ist. Pflanzen, die bei langer Beweidung eine stabile Bodendeckung und starkes Wachstum aufweisen, können einen höheren Anteil der im Auslauf anfallenden Nährstoffmengen binden und tragen somit zum Schutz von Boden und Wasser bei. Eine Grasnarbe, die zusätzlich das Nahrungssuchverhalten anregt, begünstigt Tierwohl und -gesundheit. Von den untersuchten Arten zeigte P. supina insgesamt das beste Ergebnis in Bezug auf diese Kriterien; F. arundinacea zeichnete sich zwar durch eine hohe Resistenz gegenüber der Störung durch die Beweidung aus, allerdings schien diese Art weniger stark bepickt zu werden. Wir schließen daraus, dass die Wahl der Pflanzenart für die Auslaufbegrünung als eine wichtige Methode des Auslaufmanagements betrachtet werden kann, die etablierte Methoden der Auslaufpflege, wie Umtriebsbeweidung mit ausreichenden Beweidungspausen und eine Gestaltung des Auslaufs, welche die Tiere zur Nutzung der gesamten Fläche animiert, ergänzen sollte.

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.

The objective of this thesis was to evaluate inclusion of up to 35% by-product DDGS (with reduced Ca and P) with and without addition of a proprietary premix (enzyme and antioxidant; Alltech Inc.) on productive performance and egg quality of white and brown egg laying hens. A total of 288 white or brown hens were randomly allocated to one of the following treatments: 1) corn-soybean meal (control), 2) 25% DDGS, 3) 25% DDGS plus premix, 4) 35% DDGS, and 5) 35% DDGS plus premix. Hen body weight values were impaired with addition of 25 and 35% DDGS when compared to the control. Premix helped maintain body weight comparable to control in the brown hens; however was not noted in white hens. In the second dietary phase, addition of DDGS increased feed intake in white egg laying hens and was maintained with the premix. Brown hens on premix came into lay faster than the control and DDGS diets, but DDGS reduced overall egg production. Haugh units, yolk color, and purchase intent scores were increased in brown eggs with DDGS diets. White eggs had increased yolk color with DDGS. In conclusion, up to 35% DDGS is acceptable in white laying hen diets.

Omega-3 enriched eggs serve as an important functional food to boost consumption of polyunsaturated fatty acids (PUFA) critical for good health. Because omega-3 eggs have the potential for unpleasant aromas and flavours, this research was designed to assess the fatty acid profile and sensory attributes of eggs procured from hens consuming designer diets. In the first study, the use of hemp in hen diets led to significant increases in omega-3 PUFA content and colour intensity of yolks, but did not have adverse effects on the sensory profiles of cooked eggs. Additionally, the level of docosahexaenoic acid was the same in eggs from both the lowest and highest hempseed oil groups. In order to overcome this plateau, the second study assessed diets varying in linoleic acid (LA) content. Although docosapentaenoic acid in the yolk was significantly increased with an increasing dietary LA content, docosahexaenoic acid remained unaffected by dietary treatment. In the third study, a different approach was used to reduce competition between alpha-linolenic acid (ALA) and LA. Diets containing two levels of ALA and varying ratios of saturated fatty acids (SFA): LA + oleic acid (OA) were tested. Increasing dietary SFA: LA + OA resulted in marked increases in all n-3 PUFA. The fourth study was designed to assess the interaction between dietary constituents on sensory attributes of eggs, namely omega-3 PUFA from flaxseed oil (FO), and canola meal (CM), which contains precursors to trimethylamine, which may lead to fishy taint. Oceanic flavour significantly increased with inclusion of FO, while egg, creamy and buttery flavours showed a decrease. The pairing of CM and FO resulted in a significant decrease in egg flavour compared to using FO alone. This research has demonstrated that novel ingredients like hemp can be used in laying hen diets to deposit n-3 PUFA into eggs without fear of affecting sensory outcomes. Increasing the SFA: LA + OA ratio in layer diets is most effective in increasing yolk ALA conversion into long-chain PUFA. Lastly, CM should be added to diets with caution when used in conjunction with omega-3 PUFA ingredients due to a reduction in egg flavour.