Les poules pondeuses sont susceptibles d’être exposées à des polluants organiques persistants (POP) potentiellement présents dans leur environnement. Dans un contexte de sécurisation des systèmes d’élevage avicole vis-à-vis des POP, nous avons étudié les facteurs influençant le transfert des POP ingérés vers l’œuf. Ces facteurs sont liés à la nature de la matrice ingérée (sol ou aliment), aux caractéristiques de l’animal (taux de ponte, état d’engraissement) et aux caractéristiques de la molécule (lipophilicité, susceptibilité à la métabolisation). Pour cette étude, différentes approches scientifiques ont été mobilisées : l’expérimentation in vivo et la modélisation mathématique. Les expérimentations in vivo ont permis d’étudier la biodisponibilité relative des PCB d’un sol naturellement contaminé, et de renseigner les paramètres de la cinétique de transfert vers l’œuf de molécules non encore étudiées chez la poule pondeuse telles que des molécules émergentes (exemple d’un retardateur de flammes bromé, HBCD) ou les HAP. Nos résultats montrent en particulier l’importance de l’impact du degré de métabolisation de la molécule sur l’allure de la cinétique et le niveau du transfert. L’élaboration d’un modèle mathématique dynamique a permis d’explorer l’influence des caractéristiques de l’animal sur le transfert de POP vers l’œuf. Le niveau de ponte influence directement, et de façon proportionnelle, le niveau de contamination des tissus de la poule à l’état d’équilibre. Le niveau d’engraissement a un rôle de dilution en cas de période de non ponte et influence de façon marquée la vitesse de décontamination des tissus lors d’une période d’épuration suivant une exposition / Laying hens are likely to be exposed to a wide range of persistent organic pollutants (POPs) potentially present in their environment. In the context of securing poultry farming systems regarding POPs, our research has focused on identifying and grading factors likely to influence the transfer of ingested POPs to eggs. These factors are related to the nature of the ingested matrix (soil or feed), to the characteristics of the animal (laying rate, fatness) and to the properties of the molecule (lipophilicity, sensitivity to metabolism). Different scientific approaches have been implemented: in vivo experimentation and mathematical modeling. In the frame of in vivo experiments we have assessed the relative bioavailability of PCBs from one naturally contaminated soil. In addition, we have calculated parameters of the kinetics of transfer to eggs of molecules that had never been studied in laying hens, such as emerging molecules (for example a brominated flame retardant, HBCD), or PAHs. Our results point out the dominant impact of the molecule metabolism on the shape of its kinetics and on its rate of transfer to eggs.The developed dynamic mathematical model makes it possible to pilot variations with time of the size of the lipid compartments in the animal and of the frequency of laying. It was used to assess the influence of these animal characteristics on the transfer of POPs to eggs. Laying rate proportionally influences the contamination level of eggs and of animal tissues at steady state. Body fat dilutes absorbed POPs in absence of laying and significantly influences the rate of decontamination of tissues during depuration subsequent to an exposure period

Ordet hen har introducerats i det svenska språket som ett könsneutralt pronomen. Tidigare forskning har berört den allmänna betydelsen av ordet och visar att människors attityd till ordet hen blir alltmer positiv. Denna studies syfte var att undersöka betydelsen av hen som självvalt pronomen hos personer med en ickebinär könsidentitet. Intervjuer genomfördes med åtta vuxna ickebinära personer och resultatet tolkades med en tematisk analys. Tre huvudteman framkom:​att bli till genom språket​, ​att felkönas s​amt ​att (inte) komma ut​. I resultaten framkom att hen är viktigt för ickebinäras identitet och existens, samt att det förekommer ofta att ickebinära personer felkönas genom användande av fel pronomen. Ickebinära identiteter blir ofta osynliggjorda i vardagen. Detta ogiltigförklarande av könsidentiteten som ickebinära ofta upplever leder till negativa konsekvenser för existensen och välbefinnandet. Då forskningsfältet är tidigare obeforskat utgör studien en del i att fylla en kunskapslucka på området.

Zur Klimagestaltung in Legehennenställen werden primär Unterdrucklüftungssysteme mit einem Luftwechsel nach dem Strahllüftungsprinzip entlang der Querachse des Stalls eingesetzt. Zur besseren Frischluftversorgung im Tierbereich werden zunehmend Unterdrucklüftungssysteme mit einem Luftwechsel nach dem Tunnelprinzip entlang der Längsachse des Stalls eingesetzt. Im Projekt werden die beiden Luftwechselvarianten verglichen, um Kenndaten zu ausgewählten Stallraumlasten sowie zum Luft- und Volumenstrom für die Varianten zu bestimmen und hieraus Bewertungen zu Staub-, Geruchs- und Ammoniakemissionen abzuleiten. Die Ammoniakemissionen sind bei der Tunnellüftung gegenüber Strahllüftung niedriger, die Staubemissionen sind dagegen bei der Strahllüftung geringer. Für die Geruchsemissionen wurden keine Unterschiede festgestellt. Die Voliereblöcke erzeugen im Stallraum Strömungsbarrieren und werden von der Frischluft weitgehend umströmt. Hierdurch entstehen deutliche Luftwechselunterschiede zwischen dem frei durchströmbaren Stallraum und dem Innenbereich der Voliereblöcke.

In Legehennenbeständen wurde die Schutzwirkung von vier Impfprogrammen, die der Zentralverband der Deutschen Geflügelwirtschaft e.V. empfiehlt und einer Impfung nach der Hühner-Salmonellen-Verordnung untersucht. Unterschiede in den Impfschemata konnten unter den gewählten Versuchsbedingungen nicht festgestellt werden. Eine Impfung gegen Salmonellen garantiert keine vollständige Elimination des Erregers, sondern eine Reduktion der Besiedelung der Organe sowie der Ausscheidung und der Eikontamination. Auch eine zusätzliche Impfung mit Inaktivatimpfstoffen erbrachte keinen effektiveren Schutz vor Salmonella Enteritidis und Salmonella Thyphimurium. Die Schutzwirkung einer Impfung ist am besten, wenn die Salmonellen-Exposition gering ist.

An experiment was conducted to determine whether direct-fed microbial supplementation could alleviate a marginal amino acid (AA) deficiency in Hyline 36 laying hens from 33 to 44 wk of age. The experiment was a 2 × 4 factorial design with or without a commercial directfed microbial (Primilac; 1.36 kg/1,000 kg) and 4 levels of AA formulation. Egg characteristics (yolk, albumen, or shell proportions and yolk or albumen solids) were not affected by diet. Primilac supplementation had no effect on egg production or egg mass. However, Primilac supplementation reduced feed intake-to-egg mass ratio by 2.4 and 3.4% from 33 to 36 wk and 41 to 44 wk, respectively. Total eggs laid and egg mass were greatest when at least 14.4 g of CP, 804 mg of Lys, 382 mg of Met, 601 mg of TSAA, 502 mg of Thr, and 609 mg of Ile were consumed per hen per day from 33 to 44 wk of age. In conclusion, Primilac supplementation was not able to completely alleviate a marginal AA deficiency in laying hens but did improve feed intake-to-egg mass ratios during 8 wk of the 12-wk study.

A control diet (CN diet; 17.4% CP and 4.37% Ca) was compared with an experimental diet with a 0.4-percentage-unit reduction in protein content and a 35% replacement of limestone by a CaSO4-zeolite mixture [5.76% CaSO4 and 1.18% zeolite; reduced-emission diet (RE diet)] in laying hens to evaluate the effects on apparent N retention, egg production, egg composition, and excreta pH measured at excreta collection or after 7 d of storage. In previous studies, it was demonstrated that the RE diet reduced NH3 emissions by 48%. Laying hens (192 total; 48 replicate cages per diet, with 2 hens per cage) were fed experimental diets from 33 to 49 wk of age. Apparent N retention (48.2%), egg production (83.6%), and number of shell-less eggs (0.18%) were not affected by the diet. Eggs tended to be heavier (59.4 vs. 58.8 g/egg, P = 0.06), and yolk percentage (29.7 vs. 29.0%, P = 0.013) was greater with the RE diet. At 48 wk of age, the total solids content per egg was also greater from hens fed the RE diet (13.2 vs. 12.6 g/egg, P = 0.032). Other egg components were not influenced by diet. Thus, a slight reduction in dietary CP content and replacing a portion of the Ca from CaCO3 with CaSO4 did not affect egg production nor did it impair shell quality. At the end of the experiment, excreta were collected from all cages (excreta from 3 cages were mixed and pooled; 16 pools of excreta per diet). At collection, excreta of hens fed the RE diet had lower pH (5.89 vs. 6.54, P < 0.001) than those of hens fed the CN diet. After 7 d of storage, excreta pH of hens fed the RE diet continued to be lower (6.30 vs. 8.36, P < 0.001). The reduction of excreta pH, even after 7 d of storage, may control nitrogenous emissions from excreta by maintaining excreted N as NH4+.

Sammanfattning: Syftet med denna uppsats var främst att ta reda på om pedagogerna inom skolverksamheten såg det könsneutrala pronomenet hen som ett potentiellt redskap i genusarbetet, eller om de såg någon annan funktion med begreppet. För detta ändamål använde vi oss av en kvalitativ undersökningsmetod där vi etablerade 6 fokusgrupper med tre informanter i varje grupp. Materialet dokumenterades med hjälp av diktafon. Undersökningen visade en tvetydighet gällande de intervjuades syn på kön och genus. Det skiljde sig bland pedagogerna om de såg på både kön och genus som medfött, eller om de såg genus som socialt konstruerat. Oavsett deras syn på kön och genus tyckte de flesta pedagogerna i undersökningen att hen inte skulle kunna fylla en funktion i genusarbetet. Undersökningen visade även att de flesta av pedagogerna ville stärka ”han” och ”hon” var för sig via en uppdelning. Majoriteten av pedagogerna förkastade pronomenet hen eftersom det sågs som ett hot mot en enligt dem naturlig näst intill dikotom uppdelning av könen. Pedagogerna i vår undersökning var överens om att de redan bemötte barnen könsneutralt då de betraktade barnen som individer. I analysen såg vi dock att pedagogernas åsikter om att flickor och pojkar är olika till naturen kan medföra att de snarare bemöter individen som flicka eller individen som pojke och därmed riskerar att omedvetet reproducera traditionella könsmönster.

Salmonella Enteritidis (SE) infections in laying hens is a significant cause of foodborne illness linked to the consumption of contaminated eggs. This dissertation encompasses novel strategies aimed to explore appropriate in-vitro and in-vivo models to evaluate the effects of these novel strategies to reduce SE in laying hens. Firstly, we investigated the potential probiotics, prebiotics, and essential oil combinations to reduce SE in-vitro. The results showed that probiotics and prebiotics are equally effective to reduce SE. In subsequent studies, we evaluated the role of vaccination history on cecal microbiota and SE infections with various doses of oral SE challenge. Our findings showed a dose-dependent response on fecal SE shedding in vaccinated and unvaccinated laying hens. Concurrently, we found an increased abundance of phylum Synergistota in the cecal microbiota following an SE infection, as well as a surge in the relative abundance of fatty-acid producing bacteria. The emphasizing the necessity to understand microbiota changes during SE infection for developing an effective intervention. We further researched the efficacy of a Bacillus-based probiotic and a glycan-based product to reduce SE infections in laying hens. These products were effective in reducing SE in the fecal and cecal content of laying hens. However, our research also underscored the necessity of developing a precise enumerate method to accurately measure the concentration of Salmonella in fecal and tissue samples. Overall, we expect this dissertation to contribute valuable insights into developing effective strategies to reduce SE infections in laying hens. These findings, while promising, underscore the ongoing challenge to develop a robust and effective solution to address the problem of SE in laying hens.

<p>  </p> <p>There is a clear need for more research detailing how to manage birds in cage-free housing systems. Although management guides for birds in cage-free systems focus on adult hens, previous research has established that the pullet phase is important to success later in life. Past research regarding the effects of stocking density on behavior has focused on caged adult hens, and often deals with confounding factors such as group size, limiting its interpretation. The goal of this project was to investigate the impacts of stocking density on behaviors of pullets in cage-free housing systems. </p> <p>A 2x2 randomized complete block design with two strains (Lohmann LB-Lite (Brown) and Lohmann LSL-Lite (White)) and two stocking densities (619.1 (high stocking density; HSD) and 1,248.9 (low stocking density, LSD) cm2/bird) was utilized. Videos of 6 pens for each strain by stocking density combination (59 birds/pen, n = 1416) were recorded for 2 consecutive days at 12 and 16 weeks of age (WOA). Behaviors of interest were recorded every 10 minutes for 1 hour in the morning, afternoon, and evening. Most behavior data were analyzed using a mixed model, PROC GLIMMIX, in SAS 9.4 with main effects of stocking density (SD), strain, age and time of day (TOD). Behaviors that were infrequent or that could not be transformed to meet normality assumptions were analyzed as binomial data (occurred or did not occur) and odds ratios were calculated using PROC LOGISTIC.</p> <p>Stocking density influenced every behavior examined. The LSD had fewer birds that performed eating and drinking behaviors, but more birds performed inactive, locomotion, exploratory and comfort behaviors compared to the HSD. Additionally, birds in the HSD were more likely to participate in pecking and piling behaviors compared to LSD. These results suggest that LSD may provide welfare benefits to the pullets. However, producers may face economic barriers when attempting to decrease stocking densities. Further research is needed in this area, but these results could help to achieve a stocking density that maximizes the range of behaviors pullets are able to perform within the scope of a producer’s resources. Future directions may consider collecting behavior data across the life cycle in addition to examining the relationships among behavior and welfare parameters such as feather quality, foot condition and keel bone fractures.</p>

This study aims to examine high school teachers experiences with non-binary students in different aspects of social and cultural factors. The use of the pronoun they will have a central role in terms of how teachers perceive its signification and function in everyday meetings with non-binary students. From its origin, circa 1970, to todays modern society the pronoun they have changed the view of the LGBTQ-circles (in background of greater influence) which has given a better general understanding of different identities and their internal processes. In this context, this study is gender orientated in the sense of how non-binary students are internalized in the educational system of Sweden today. The questions asked are solely based on teachers perceptions of these specific meetings with non-binary students. The answers given, by conducting interviews with 4 different teachers, showed that the experiences were similar to each other in many aspects. In its more simplified version the study showed that institutions are perceived as more modernized in the sense of educational inclusion but distinct complexities were instead more visible in deeper levels of human interaction, for example cultural differences were shown to be clear as to how binary and non-binary students interact. The respondents also confirmed that the educational possibilities of non-binary students are still marginalized by traditional influence, despite modern changes. More specifically, norms were shown to be distinguished in everything from language to teaching materials which gives the impression of a societal model, in its traditional sense, that is being reinforced by gender binary ambitions. / Denna studie ämnar att undersöka högskolelärares erfarenheter i mötet med icke-binära elever i olika aspekter av sociala- och kulturella faktorer. Användningen av pronomenet hen kommer att ha en central roll i termer av huruvida lärare ser på dess betydelse och funktion i vardagliga möten med icke-binära elever. Från sitt ursprung, ca 1970, till dagens moderna samhälle har pronomenet hen förändrat den samhälleliga bilden av HBTQ-kretsar (i bakgrund till ökat inflytande), vilket har giviten mer generell förståelse för olika identiteter och deras interna process. I denna kontext är studien orienterad kring genus i den mening att undersöka hur icke-binära identiteter är internaliserade i det svenska utbildningssystemet idag. Frågorna som besvaras är enbart baserade på lärares upplevelser av specifika möten med icke-binära elever.  Svaren som gavs, genom att leda intervjuer med 4 olika lärare, visade att erfarenheterna sinsemellan alla respondenter var likadana i många aspekter. I sin enklare version visade studien att institutionen uppfattas som moderniserad i mening av inkludering men andra distinkta komplexiteter blev istället synligare på ett djupare plan av mänskliga interaktioner, t.ex visade sig att kulturella skillnader var tydligare mellan binära och icke-binära elever. Respondenterna bekräftade också att utbildningsmöjligheterna för icke-binära elever kan tolkas som marginaliserade genom inflytandet av tidigare traditioner, trots moderna förändringar. Mer specifikt visade det sig att normer kunde urskiljas i allt från språk till läromedel, vilket gav intrycket av en traditionsenlig samhällsmodellsom underbyggs av könsbinära ambitioner.