Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study was conducted to investigate the effect of aflatoxins consumption (AFL), in broiler breeders of different strains. To evaluate reproductive and productive aspects of broiler breeders intoxicated with AFL were used 660 females and 60 males, distributed in a completely randomized design with factorial arrangement with three levels of AFL (0.0, 0.50 and 1.0 mg/kg diet) and two strains, Cobb 500® (LA) and Hybro PG® (LB), totalizing six treatments with five replicates pens of 22 females and 2 males each. The period of intoxication was from 24th to the 64th weeks of age, from 65th to the 70th weeks; all birds were fed a AFL free diet, with the objective of assessing the residual effects. To evaluate the progenies, three experiments were performed from 1 to 21 days. Each one used 600 day old males, from eggs produced by the breeders of the experiment above, at 32, 48 and 64 weeks of age. For each experiment, the same design used in the evaluation of breeders was used, in a total of six treatments with 10 replicates of 10 males each. The laying rate was depreciated by the addition of AFL in the diet. This negative effect was more pronounced when it was added 1mg of AFL/kg, indicating a dose-dependent effect. LB breeders had higher eggs production than LA. Breeders from LA, intoxicated with 0.5mg AFL/kg diet, showed a greater reduction in egg production than birds LB, intoxicated with the same level of AFL. The hatching was not influenced by the AFL in the breeders diets. LB breeders had a poorest fertility and hatching. The hatchability of eggs from breeders intoxicated with 1mg AFL/kg of diet was the lowest, caused by an increase in embryo mortality in the third week of incubation. Evaluating the interaction among AFL and strains, there was a negative effect on the fertility rate only in the LB, when 0.5 or 1.0mg AFL/kg were added to the diets. The progeny from breeders intoxicated with 1mg AFL/kg diet had the lowest body weight at birth and 21 days, in the three experiments. LA breeders produced the heaviest chicks at birth and at 21 days. Studying the interaction AFL and strain, it was observed that AFL intoxication in LB did not affect progeny s initial weight, but in LA, there was a decrease in day old chicks weight produced by intoxicated breeders. The studied levels of AFL influenced negatively the performance of breeders and their progeny. The two strains showed different responses in some of the parameters studied, when they were fed with diets containing AFL. / Este estudo foi conduzido para investigar o efeito do consumo de aflatoxinas (AFL) por matrizes de corte de diferentes linhagens. Para avaliar aspectos produtivos e reprodutivos de matrizes de corte intoxicadas com AFL, foram utilizadas 660 fêmeas e 60 machos, distribuídas em delineamento inteiramente casualizado em arranjo fatorial, com três níveis de AFL (0,0; 0,50 e 1,0 mg/kg de dieta) e duas linhagens, Cobb 500® (LA) e Hybro PG® (LB), totalizando seis tratamentos com cinco repetições de 22 fêmeas e 2 machos cada. O período de intoxicação foi da 24ª à 64ª semana de idade, da 65ª à 70ª semana, todas as aves receberam dietas isentas de AFL, com a finalidade de avaliar efeitos residuais. Para avaliar as progênies, foram realizadas três avaliações de 1 a 21 dias. Cada uma utilizou 600 pintos machos de um dia, provenientes de ovos produzidos por matrizes do experimento acima, na 32ª, 48ª e 64ª semanas de idade. Para cada avaliação, foi adotado o mesmo delineamento utilizado na avaliação das matrizes, totalizando seis tratamentos com 10 repetições de 10 machos cada. A taxa de postura foi depreciada pela adição de AFL na dieta. Esse efeito negativo foi mais acentuado quando foi adicionado 1mg de AFL/kg, indicando um efeito dose dependente. Aves LB apresentaram uma produção de ovos superior a da LA. Matrizes LA, intoxicadas com 0,5mg AFL/kg de dieta, apresentaram uma redução maior na produção de ovos que aves LB, intoxicadas com o mesmo nível de AFL. A eclosão não foi influenciada pelas AFL na dieta das matrizes. Aves da LB apresentaram pior fertilidade, reduzindo a taxa de eclosão da mesma. A eclodibilidade de ovos provenientes de aves intoxicadas com 1mg AFL/kg de dieta foi inferior às demais, devido a um aumento da mortalidade embrionária na terceira semana de incubação. Avaliando a interação entre AFL e linhagens sobre a taxa de fertilidade, verificou-se uma redução desta na LB, quando 0,5 ou 1,0mg AFL/kg foram adicionadas às dietas. A progênie de matrizes intoxicadas com 1mg AFL/kg de dieta apresentou um peso corporal inferior às demais, no primeiro e 21º dia, nas três avaliações realizadas. Matrizes da LA produziram pintos mais pesados ao nascer e aos 21 dias. Estudando a interação AFL e linhagens, observou-se que a intoxicação por AFL em matrizes da LB não afetou o peso inicial da progênie, porém, na LA, observou-se um decréscimo no peso de um dia de pintos produzidos por matrizes intoxicadas. Os níveis de AFL estudados prejudicaram o desempenho das matrizes e de suas progênies. As duas linhagens apresentaram respostas distintas em alguns dos parâmetros estudados, quando as mesmas foram submetidas à dietas contendo AFL.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The need to improve the reproductive performance of broiler breeders have been contributed to development of new concepts and products in animal nutrition. Carophyll Red® has in your composition canthaxantin. Has been accepted that canthaxantin has high antioxidant capacity.The 25-(OH)D3 (25-hydroxycholecalciferol), an intermediary between the vitamin D3 and the active form of this vitamin D. This is allied with the metabolism and transfer of calcium from the shell to the embryo. HY-D® is a form of vitamin D, his composition. Rovimix® Maxichick is the association of canthaxanthin and 25-(OH)D3. The experiment was conducted with the objective to evaluate the use of canthaxanthin and/or 25- hydroxycholecalciferol (25-(OH)D3) on performance of broiler breeders. Its was used 264 females and 24 males COBB 500® broiler breeders with 25 to 52 weeks of age. The diets were composed basically of vegetable ingredients, based on corn and soybean meal. It was used four treatments: 1 - control diet, 2 - control diet with addition of 25-(OH)D3, 3 - control diet with addition of canthaxanthin (CX), 4 - control diet with a combination of these two active ingredients (25-(OH)D3 + CX). The parameters evaluated were body weight, laying rate, egg weight, specific gravity, weight of albumen, yolk and shell percentage, albumen, yolk and shell, yolk color and oxidation. To evaluate the laying rate were performed six daily collections during the experimental period. Eggs collect a day of week were used for all others analysis. The egg production rates were not affected by different treatments (P=0.5151).The egg, yolk and albumen weight s and specific gravity were not affected by treatments (P>0.05). Broiler breeders fed canthaxanthin in diet had highest deposition of carotenoids in the yolk. / A necessidade de melhorar o desempenho reprodutivo de matrizes de corte contribuí para os conceitos de desenvolvimento e novos produtos na alimentação animal. Carophyll Red® tem na sua composição cantaxantina, a qual é estudada pela sua capacidade antioxidante 25 - (OH)D3 (25-hidroxicolecalciferol), um intermediário entre a vitamina D3 e da forma ativa da vitamina D. Esta, é aliada com o metabolismo e transferência de cálcio da casca para o embrião. HY-D® possui na sua composição 25 - (OH)D3. Rovimix Maxichick® é a associação de cantaxantina e 25 - (OH)D3. O experimento foi conduzido com o objetivo de avaliar o uso da cantaxantina e / ou 25 - (OH)D3 sobre o desempenho de matrizes de corte, Cobb® entre 25e 52 semanas de idade. As dietas foram compostas basicamente de ingredientes vegetais, tendo por base milho e farelo de soja. Foram utilizados quatro tratamentos: 1 - dieta controle (sem aditivos em estudo), 2 - dieta controle com adição de 25 - (OH) D3, adicionando o produto HY-D®, 3 - dieta controle com adição de cantaxantina (CX) através da inclusão do produto Carophyll Red®, 4 - dieta com a associação dos princípios ativos (25 - (OH)D3 + CX) com o uso de Rovimix® MaxiChick. Foram avaliados o peso corporal, taxa de postura, peso dos ovos, densidade específica de ovos, peso do albúmen, gema e casca e porcentagem de albúmen, gema e casca, coloração da gema e a peroxidação de lipídios da gema. Para avaliar a taxa de postura foram realizadas seis coletas diárias durante todo o período experimental. Todos os ovos de uma coleta por semana foram utilizados para análise dos outros parâmetros. Os diferentes tratamentos não afetaram a taxa postura no período (P=0,5148). A gravidade específica, pesos de gema, albúmen e casca de ovo também não foram afetados pelos tratamentos (P>0,05). Matrizes pesadas que receberam cantaxantina na dieta, apresentaram maior deposição de carotenóides na gema.

The prevalence of antimicrobial residues in table eggs produced in Khartoum State, Sudan was estimated and determined. All available producing layer farms in the state were sampled in April, June and August 2008. For each layer house three egg samples were randomly collected to increase the sensitivity of antimicrobial residue screening test detectability. In total, 933 egg samples were analyzed, collected from 175 layer farms (335 layer houses) in three periods of collection. An in-house residue detection test using Geobacillus stearothermophillus var calidolactis was the analytical procedure used for the analysis. Data were analysed using Survey Toolbox to calculate the true prevalence and confidence intervals. The proportion of layer farms with antimicrobial residues in April, June and August was 61.1%, 60.2% and 68.7% respectively. The proportion of layer houses affected in April, June and August were 56.0%, 54.1% and 57.1% respectively. The results showed insignificant variation among the three periods of the surveillance (p = 0.57). A census covering all three localities of the state (Khartoum, Bahry and Omdurman) was carried out in late 2007 and early 2008. Data were recorded on areas where farms occur, number of houses per farm, total capacity of birds and farming systems. The census showed that there were 252 layer farms in the state distributed in 31 different areas with a total population of 2 221 800 birds. A structured questionnaire survey was carried out in April 2008 in the state, to assess and collect data on risk factors associated with the presence of antimicrobial residues in table eggs. The questionnaire investigated antibiotic usage patterns for each layer farm as well as the basic knowledge and understanding of farmers about public health concerns associated with antibiotic use in food producing animals. Questions were closed ended and data was obtained through direct interviews with farm owners and managers. Descriptive statistical analysis was carried out on the information captured; calculating frequencies, graphs and measures of association, using the EpiInfo™ statistical package. Ninety two farms were surveyed 98% of which comprised open-sided houses. It was found that 48.9% of the farms surveyed were on antibiotic treatment when the survey was conducted, while 58.7% of the farms had used antibiotics within the last three months. There was a significant association between having disease on the farm and using antibiotics (P<0.001). The study showed that there is a serious lack of knowledge about the dangers of using antibiotics in animals and their potential impact on human health. In addition, Sudan lacks any type of formal control of veterinary drugs in terms of legislated residue limits or monitoring and surveillance programmes. This leads the authors to the conclusion that all Sudanese consumers are at risk for ARs in eggs. / Dissertation (MSc)--University of Pretoria, 2010. / Production Animal Studies / unrestricted

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.

Large White turkey breeder hens were used to examine the effect of duration of feed restriction, prebreeder protein content, and nesting material on subsequent growth and reproductive performance. Day old poults were raised following standard commercial practices with feed and water for ad libitum consumption until 6 wk of age (WOA). At this time, hens were equally divided among six grower feeding regimens. The treatments were as follows: a) a control group fed standard commercial diets for ad libitum consumption (CON); b) a second control group like (a) but fed plain white oats from 19 through 26 wk (OATS). In contrast, the 4 remaining treatment groups were feed restricted beginning at 6 WOA to achieve body weights 45% less than the full-fed CON at 16 WOA. Birds were kept at this level of restriction until either 17.0 (R17.0), 18.3 (R18.3), 19.6 (R19.6), or 20.9 (R20.9) WOA. Thereafter, feed allowance was gradually increased to achieve a predetermined minimum target BW of 10.8 kg at photostimulation. An additional prebreeder protein treatment was superimposed from 27 to 31 WOA. Treatments reduced BW but none of the four quantitatively restricted groups achieved the target BW of 10.8 kg at photostimulation. Feed restriction reduced feed consumption and improved feed conversion. There were no differences in flock uniformity, sexual maturity, mortality, body composition at photostimulation, and total egg production. The R18.3 treatment achieved the highest peak production. The quantitative restriction treatments exhibited low laying persistency. There were no differences in number of large yellow follicles, egg weight, fertility, or hatchability, but poult weight was reduced in the R18.3 treatment. Dietary protein influenced the proportions of multiple follicle sets and percentage misshaped eggs.Three nesting materials were compared and were as follows: 1) all nests filled with shavings (S), 2) all nests filled with paper chips (P), and 3) two nests filled with shavings and two nests with paper chips (S/P). There were significant differences in percentage floor and broken eggs. Nesting materials did not affect total egg production, fertility, or hatchability. The data suggest, if restriction is too severe and is continued too near to the time of conventional photostimulation, BW recovery and egg production will be depressed. Oat feeding was the easiest treatment to implement and resulted in equivalent reproductive performance. Dietary protein content may affect proportions of multiple follicle sets. Turkey breeder hens can and do distinguish between nesting materials and this may affect floor laying. Combinations of various types of nesting materials within the same breeder unit should be avoided. (Key words: turkey breeder hens, feed restriction, prebreeder protein, egg production, body composition, nesting material) / Ph. D.

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.