<p> The northern fowl mite (<i>Ornithonyssus sylviarum</i>) is an obligate blood-feeding ectoparasite of poultry that can cause decreased egg production, profit loss, anemia, irritation to flocks and personnel, and death to hens in extreme cases. This study aimed to investigate the effects of the northern fowl mite (NFM) on laying hen performance and welfare quality beginning at 17 weeks of age. Two flocks (Trials 1 and 2) involved 800 Tetra Brown hens (n=200 per room) housed in four cage-free rooms at the Purdue University Poultry Unit. Two rooms were infested with NFM and two rooms served as controls. In Trial 1, initial NFM infestation occurred at 24 weeks on 2% (4 hens) in each of the NFM rooms. Because NFM populations were scarce, a second infestation on 2% of hens occurred at 35 weeks. A final attempt to infest with NFM occurred at 41 weeks with all hens in NFM rooms being infested. In Trial 2, initial NFM infestation occurred at 24 weeks on 2% (4 hens) in each of the NFM rooms and a second infestation took place on 2% of hens at 30 weeks of age to boost the NFM population. Egg production and mortality were recorded daily and case weights were recorded weekly. Monthly Welfare Quality® assessments were taken, as well as monthly mite counts on all birds beginning at 28 weeks. Mite checks were conducted periodically on 25% (50 hens) in all rooms between weeks 25 and 38. Data were analyzed in SAS® using the GLM procedure and an ANCOVA and all significant statistical differences were reported at P < 0.05. Proportion of hens with a mite infestation was treated as the covariate. In Trial 1, regardless of treatment, mortality increased dramatically after 21 weeks, leading to a loss of 473 hens by period 7. NFM hen-day production percentage (HD) was approximately 2% lower than the Tetra management guide and control HD was 7% higher than the Tetra management guide. In Trial 1, treatment had an effect on HD, case weights, and feather damage on the belly (P < 0.05). Proportion of hens infested with mites had an effect on percent shell and feather damage on the belly. Cannibalism and pecking in Trial 1 led to extreme feather loss, high mortality, and negatively impacted production parameters. Feather loss and high mortality contributed to the low NFM populations. In Trial 2, percent livability remained high (approximately 97% for both groups) and HD remained slightly lower than the Tetra management guide (9% and 8% lower for control and NFM), respectively. In Trial 2, treatment had an effect on eggs per hen housed, mortality, feather damage on the head and neck, and skin lesions (P < 0.05). Proportion of birds infested with mites had an effect on feather damage on the back, crop, head, and neck (P < 0.05).</p>

<p dir="ltr">Due to increasing legislative and societal demand for humane egg production, an increased production of cage-free eggs is inevitable. Past research has focused on the impact of cage-free housing systems (CFS) on laying hens' performance, health, and space use; however, limited studies have examined the impacts of CFS on the behavioral activities of laying hens, particularly in single-tier floor systems in the U.S. Broadly, this research examined the influence of two housing systems on the behavior of laying hens as they age. Specifically, the study aimed to provide information on how dissimilar cage-free systems meet the behavioral needs of laying hens. </p><p dir="ltr">Two hundred pullets were randomly assigned to either a single-tier floor room (SFR) or a modified multi-tier aviary room (MAR) at 17 weeks of age (WOA), where they remained until 85 WOA. Starting at 55 WOA, thirty focal birds were marked with non-toxic markers for individual identification in each room. The behavior of the birds was recorded continuously over two consecutive days during the mid-laying (55 WOA) and late-laying (85 WOA) phases. The behavioral expressions of the focal birds were annotated using 10-min continuous sampling at 5 time points (10 minutes after lights-on (TOD 1), 4 hr after lights-on (TOD 2), 8hr after lights-on (TOD 3), 12 hr after lights-on (TOD 4), and 10 minutes before lights-off (TOD 5)). At each of these 5 time points, 4 birds were randomly selected for observation. Behavior duration and frequency data were analyzed using PROC GLIMMIX in SAS 9.4, with the main effects of housing system (HS), age, and time of day (TOD). Descriptive statistics were used to present the behavioral time budgets of marked and unmarked birds in MAR and SFR. Further, the behaviors performed in different spatial zones (areas within each room) were presented as the percentage of observed time laying hens spent engaged in a specific behavior over the total time at a particular spatial zone. </p><p dir="ltr">Birds in MAR and SFR spent most of the observed time perching at all ages. The birds (marked and unmarked) performed environmental pecking and foraging for the highest percentage of time in the litter area of SFR and MAR. Similarly, the percentage of time the birds (marked and unmarked) spent preening and performing OCB (wing flapping, stretching, and feather-ruffling) was highest when they occupied the litter zone of MAR and SFR. Housing system influenced the time that both marked and unmarked birds spent performing foraging and environmental pecking (EP) such that marked and unmarked birds in SFR spent more time engaged in these behaviors than marked and unmarked birds in MAR (Marked: SFR vs. MAR, P = 0.043; Unmarked: SFR vs. MAR, P = 0.002). Further, marked and unmarked birds in SFR exhibited a higher frequency of EP than birds in MAR (Marked: SFR vs. MAR, P = 0.02; Unmarked: SFR vs. MAR, P < 0.001). The frequency of locomotion (standing and walking) activity differed between SFR and MAR birds. Birds (marked and unmarked) stood more frequently in SFR than in MAR (Marked: SFR vs. MAR, P = 0.046; Unmarked: SFR vs. MAR, P < 0.001). Further, SFR birds had a higher walking frequency than MAR birds (Marked: P = 0.003; Unmarked: P = 0.02). Birds (marked and unmarked) in MAR perched more frequently than SFR birds (Marked: SFR vs. MAR, P < 0.001; Unmarked: SFR vs. MAR, P = 0.01); however, unmarked birds preened more frequently in SFR than in MAR (P < 0.001). Regarding time of day, both marked and unmarked birds exhibited higher preening frequency 10 mins after lights-on (TOD 1) than at other times of day (P < 0.001). Similarly, marked birds perched for a longer duration early in the morning (TOD 1) and late at night (TOD 5), than at TOD 2 and TOD 3 (P < 0.001). </p><p dir="ltr">This study revealed that MAR and SFR may differ in how they accommodate the behavioral needs of laying hens, with hen activity levels varying between the two types of housing systems. Further research is needed to understand the implications of behavioral outcomes for the welfare of laying hens in different types of CFS.</p>

Inovação em produção animal tem sido cada vez mais exigido pelos consumidores. No ambito de produção de postura, a maior demanda é por ovos provenientes de sistemas alternativos às gaiolas tradicionais, majoritariamente pelas tendencias observadas na Europa, e dessa forma, pesquisas ressaltando a realidade brasileira estão sendo realizadas. O objetivo deste estudo foi avaliar parametros produtivos e de bem-estar em dois contextos de sistemas produtivos, sob variadas densidades de alojamento. Para isso 250 aves Lohmann Brown&reg; foram distribuídas em delineamento inteiramente casualizado (DIC) com os tratamentos organizados em esquema fatorial 2 x 4, sendo 2 sistemas de alojamento (convencional e cage-free) e 4 densidades (375,00; 450,00; 562,50 e 750,00 cm2/ave), com 6 repetições. O período experimental foi de 21 a 36 semanas de idade das poedeiras, totalizando 4 ciclos de 28 dias cada. Foram avaliados desempenho produtivo (produção de ovos, consumo de ração, conversão alimentar por kg de ovos), qualidade de ovos (peso, coloração de gema, índice gema, % de gema, % albumen, % casca, espessura e resistência a quebra, e unidade Haugh) e indicadores de bem-estar (frequência respiratória e cardíaca, temperatura clocal, escore de lesão corporal, concentração d eIgY na gema) Observou-se interação entre sistema de produção e densidade de alojamento para: % postura, consumo de ração, conversão alimentar por kg de ovos, peso do ovo, % de gema, % albúmen, espessura de casca. O aumento de densidade promoveu efeito significativo para % postura, consumo de ração, temperatura cloacal, lesão em quilha e em pés. O tipo de sistema de produção afetou consumo de ração, conversão alimentar por kg de ovos, peso do ovo, coloração de gema, índice gema, resistência à quebra, frequência cardíaca temperatura cloacal, lesões de quilha e pés e concentração de IgY na gema. Os resultados deste estudo demonstram que tanto o sistema de produção quanto a densidade de alojamento estão ligados a efeitos produtivos, de qualidade de ovos, e de bem-estar animal. / Innovation in animal production has been increasingly demanded by consumers. In the field of egg production, the greatest demand is for eggs coming from alternative systems to traditional cages, mostly from the trends observed in Europe, and thus, research highlighting the Brazilian reality is being carried out. The objective of this study was to evaluate productive and welfare parameters in two contexts of productive systems, under different stocking densities. For this purpose, 250 Lohmann Brown&reg; birds were distributed in a completely randomized design with treatments arranged in a 2 x 4 factorial scheme, with 2 housing systems (conventional and cage-free) and 4 densities (375.00; 450.00, 562.50 and 750.00 cm2 / bird), with 6 replicates. The experimental period was 21 to 36 weeks of age, totalling 4 cycles of 28 days each. (Egg weight, feed intake, feed conversion per kg of egg), egg quality (weight, yolk color, yolk index, % yolk,% albumen,% shell, shell thickness and resistance to breakage, and Haugh unit) and indicators of welfare (respiratory rate and heart rate, body temperature, body lesion score, IgY concentration in the yolk). The interaction between production system and housing density was observed for: % laying, feed intake , feed conversion per kg of eggs, egg weight, % yolk, % albumen, shell thickness. The increase in density had a significant effect on % laying, feed intake, cloacal temperature, keel and foot injury. The type of production system affected feed intake, feed conversion per kg of egg, egg weight, yolk color, yolk index, breaking strength, cloacal temperature, keel and foot lesions, and IgY concentration in the yolk. The results of this study demonstrate that both the production system and housing density are linked to productive effects, egg quality, and animal welfare.

Inovação em produção animal tem sido cada vez mais exigido pelos consumidores. No ambito de produção de postura, a maior demanda é por ovos provenientes de sistemas alternativos às gaiolas tradicionais, majoritariamente pelas tendencias observadas na Europa, e dessa forma, pesquisas ressaltando a realidade brasileira estão sendo realizadas. O objetivo deste estudo foi avaliar parametros produtivos e de bem-estar em dois contextos de sistemas produtivos, sob variadas densidades de alojamento. Para isso 250 aves Lohmann Brown&reg; foram distribuídas em delineamento inteiramente casualizado (DIC) com os tratamentos organizados em esquema fatorial 2 x 4, sendo 2 sistemas de alojamento (convencional e cage-free) e 4 densidades (375,00; 450,00; 562,50 e 750,00 cm2/ave), com 6 repetições. O período experimental foi de 21 a 36 semanas de idade das poedeiras, totalizando 4 ciclos de 28 dias cada. Foram avaliados desempenho produtivo (produção de ovos, consumo de ração, conversão alimentar por kg de ovos), qualidade de ovos (peso, coloração de gema, índice gema, % de gema, % albumen, % casca, espessura e resistência a quebra, e unidade Haugh) e indicadores de bem-estar (frequência respiratória e cardíaca, temperatura clocal, escore de lesão corporal, concentração d eIgY na gema) Observou-se interação entre sistema de produção e densidade de alojamento para: % postura, consumo de ração, conversão alimentar por kg de ovos, peso do ovo, % de gema, % albúmen, espessura de casca. O aumento de densidade promoveu efeito significativo para % postura, consumo de ração, temperatura cloacal, lesão em quilha e em pés. O tipo de sistema de produção afetou consumo de ração, conversão alimentar por kg de ovos, peso do ovo, coloração de gema, índice gema, resistência à quebra, frequência cardíaca temperatura cloacal, lesões de quilha e pés e concentração de IgY na gema. Os resultados deste estudo demonstram que tanto o sistema de produção quanto a densidade de alojamento estão ligados a efeitos produtivos, de qualidade de ovos, e de bem-estar animal. / Innovation in animal production has been increasingly demanded by consumers. In the field of egg production, the greatest demand is for eggs coming from alternative systems to traditional cages, mostly from the trends observed in Europe, and thus, research highlighting the Brazilian reality is being carried out. The objective of this study was to evaluate productive and welfare parameters in two contexts of productive systems, under different stocking densities. For this purpose, 250 Lohmann Brown&reg; birds were distributed in a completely randomized design with treatments arranged in a 2 x 4 factorial scheme, with 2 housing systems (conventional and cage-free) and 4 densities (375.00; 450.00, 562.50 and 750.00 cm2 / bird), with 6 replicates. The experimental period was 21 to 36 weeks of age, totalling 4 cycles of 28 days each. (Egg weight, feed intake, feed conversion per kg of egg), egg quality (weight, yolk color, yolk index, % yolk,% albumen,% shell, shell thickness and resistance to breakage, and Haugh unit) and indicators of welfare (respiratory rate and heart rate, body temperature, body lesion score, IgY concentration in the yolk). The interaction between production system and housing density was observed for: % laying, feed intake , feed conversion per kg of eggs, egg weight, % yolk, % albumen, shell thickness. The increase in density had a significant effect on % laying, feed intake, cloacal temperature, keel and foot injury. The type of production system affected feed intake, feed conversion per kg of egg, egg weight, yolk color, yolk index, breaking strength, cloacal temperature, keel and foot lesions, and IgY concentration in the yolk. The results of this study demonstrate that both the production system and housing density are linked to productive effects, egg quality, and animal welfare.

The overall purpose of this thesis is to understand the impact of management on commercial egg layers, whether that be environmental-related, health-related, or other possible stressors within the pullet and post-peak phases. Furthermore, the study seeks to examine what effects to performance and production these impacts may induce within a commercial layer in differing phases, specifically the pullet and post-peak phases. Chapter two explores into coccidiosis within the pullet phase, which induced by a commercial vaccine, can provide stress to a pullet, lowering protection against infection, and seriously compromising its growth and development into peak lay. Chapter three explores into the post-peak phase, a transition from a caged system of production to cage-free system of production was selected. incorporating multiple differing environmental stimuli that can induce stress. If commercial layers prove to possess the capabilities to adapt to these impacts in multiple phases, the possibility of extended production is possible.