<p dir="ltr">Stocking density, space availability, and lameness are important aspects affecting broiler chicken behavior and welfare. Stocking density refers to the weight of broiler chickens per a set area of space typically measured as kg/m2. Space availability is the amount of space per individual broiler chicken typically measured as m2/bird. Stocking density and space availability can contribute to lameness and other aspects of welfare such as footpad dermatitis, hock burn, and feather cleanliness. The behavior of broiler chickens can also be modified by stocking density, space availability, and lameness. All of these aspects are typically related to a change in activity levels which could be used as an indicator of animal welfare. To date, the majority of research that has examined the walking ability of broiler chickens has assessed how stocking density influences the development of gait problems when applied during the grower phase. However, not all broilers develop gait problems at the same point in time and it is unknown whether broilers that initially have sound gait develop gait problems at a similar rate to broilers that are initially classified as having affected gait. Further, the influence of stocking density on the progression of gait abnormalities of broilers with sound and poor gait is unknown. Finally, since space becomes more and more limited as broiler chickens increase in body weight and age, it is unknown how the provision of space during the finisher phase, when broiler chickens are gaining weight rapidly, can influence their walking ability and welfare outcomes. Stocking density is calculated based on projected final weights of broiler chickens from the time they are placed on a commercial farm, and that projected stocking density remains the same from the chick placement date. As stocking densities are increased, there is also an increase in the prevalence of lameness. Age is also known to be related to walking ability, and as broiler chickens age, there is an increase in the prevalence of lameness. While it is known that increasing stocking density and aging are both contributing factors to broiler chicken lameness, there is no previous research on if reducing stocking density at a later age can help alleviate the prevalence of lameness. To address this knowledge gap, two studies were conducted. In the first study, 784 mixed-sex Ross 708 broiler chickens in commercial barns were placed into of four treatment groups. · SOUND: Consisted of broiler chickens that were considered to have sound gait (scores of 0 and 1) and the broilers were housed at farm stocking density (6lb/ft2, 29.29 kg/m2), · AFFECTED: Consisted of broiler chickens that were considered to have affected gait (scores of 2 or higher) and were housed at farm stocking density (6lb/ft2, 29.29 kg/m2) · MIXED-F: Consisted of 50% of broiler chickens that were considered to have sound gait and 50% that were considered to have affected gait and were housed at farm stocking density (6lb/ft2, 29.29 kg/m2) · MIXED-L: Consisted of 50% of broiler chickens that were considered to have sound gait and 50% that were considered to have affected gait and were housed at half of the farm stocking density (3lb/ft2, 14.65 kg/m2) Broiler chickens were randomly selected at 33 days of age from each of four commercial barns for welfare assessments, which included gait scoring to assess walking ability, as well as the assessment of footpad dermatitis and hock burn. Broilers were then assigned to one of two gait categories based on their gait scores. Broilers were either considered to have sound gait meaning they had no or unidentifiable abnormalities, or affected gait meaning there were identifiable abnormalities. To separate treatment groups, custom-built pens (4 ft x 12 ft, 1.22 m x 3.66 m) were constructed. At 37 days of age welfare assessments were conducted again, and then the broiler chickens were placed back into the flock (Chapter 2). The behavior of the broiler chickens was recorded from the evening of day 33 to the morning of day 37 and video was analyzed using scan sampling. The proportion of broiler chickens performing target behaviors was recorded every 10 minutes in the morning (6:00 – 8:00) and evening (19:00 – 21:30). Better gait scores were observed at 37 days of age in broiler chickens in the MIXED-L group and broiler chickens in the SOUND group. The presence of hock burn was lower in broiler chickens in the SOUND group. Cleanliness scores were better for broiler chickens in the MIXED-L group and in broiler chickens in the SOUND. Stocking density impacted the proportion of broilers performing eating, drinking, sitting, and walking (P < 0.05). Walking ability impacted the proportion of broiler chickens standing, walking, and sitting (P < 0.05). To continue investigating the implementation of housing changes later in the broiler chickens’ life, a second study was conducted using 705 mixed-sex Ross 708 broiler chickens. At 7 d, broiler chickens were randomly assigned to 1 of 16 pens (46-47 birds/pen). At 28 d, half of the pens doubled in size after welfare assessments were completed (measuring 8 ft x 10 ft, 3.05 m x 2.44 m, DOUBLE), while the other half remained at the original dimensions (8 ft x 5 ft, 2.44 m x 1.5 m, SINGLE). The DOUBLE pens had an expected stocking density of 15.2 - 15.5 kg/m2 (3.11 - 3.17 lb/ft2) and an estimated space availability of 0.15 to 0.16 m2/bird while the SINGLE pens had an estimated stocking density of 30.4 - 31.1 kg/m2 (6.23-6.37 lb/ft2) and an estimated space availability of 0.07-0.08 m2/bird. Welfare assessments consisting of scoring gait, feather cleanliness and for the presence of FPD and hock burn were conducted at 22 d, 28 d, and 38 d (Chapter 4). At 38 d, broiler chickens in SINGLE pens were less likely to have a score of 0 for FPD (Wald c2 = 15.45, P < 0.0001), hock burn (Wald c2 = 7.26, P = 0.0071), and feather cleanliness (Wald c2 = 11.77, P = 0.0006) than broiler chickens in DOUBLE pens. However, broiler chickens in SINGLE pens were more likely to have a gait score of 0 compared to broiler chickens in DOUBLE pens (Wald c2 = 11.34, P = 0.0008). Broiler chicken behavior was recorded at 23-26 d (Period 1: before space increase), 28-31 d (Period 2: time of space increase), and 36-37 d (Period 3: after space increase). Behavior data were collected using focal sampling for two broiler chickens per each of the 16 pens in the morning, afternoon, and evening (Chapter 5). Broiler chickens housed in double pens had an increased frequency of leg extensions compared to broiler chickens housed in single pens (P < 0.05). Period had a significant impact on the frequency of eating, sitting, and walking and the durations of sitting, environmental pecking, standing, and walking (P < 0.05). Time of day had a significant impact on the frequency of eating, sitting, walking, preening, and leg extensions and the durations of sitting, eating, preening, and standing (P < 0.05). The interaction of age and time of day had a significant impact on the frequency of drinking and leg extensions and the durations of sitting, eating, and walking (P < 0.05). The interaction of age and treatment had a significant impact on the frequency of eating and walking and the duration of preening (P < 0.05). In conclusion, broiler chickens housed in DOUBLE pens did not exhibit a difference in behaviors compared to those in SINGLE pens, other than broilers in the DOUBLE pens performing leg extensions more often. While the first study indicated that having more space available per broiler chicken led to better walking ability, the second study showed the opposite to be true as those with more space had reduced walking ability. This indicates that changing the stocking density through manipulating space in the finisher phase may impact welfare, but further investigation is needed. Future research should first examine the effects of adding space in the finisher phase with 3 treatment groups. While the two discussed here would remain the same, the third group should start with broilers in a pen that is already the size of the DOUBLE pens and remains that way for the entire project. This will ensure that increasing space during the finisher period is beneficial rather than the additional space availability in general accounting for the differences in treatments. All treatment groups should also get fresh bedding with the pen increase to ensure the welfare measurement results are due to the changes in space availability rather than the provision of fresh litter.</p>

In commercial settings, broiler chickens and rainbow trout are housed in barren environments under high stocking densities, due to an emphasis on production efficiency. These monotonous housing conditions do not provide broilers or trout with the ability to perform functional, highly-motivated behaviors and increase their susceptibility to excessive anxiety and fear, resulting in negative affective states and poor animal welfare. Affective state (or emotional state) is a cumulative product of short-term life experiences, ranging from positive to negative. Because affective states are largely influenced by environmental condition, determining animal affective state can provide useful information on how to improve housing conditions in order to ensure positive experiences and good animal welfare. Cognitive processes are closely associated with affective state; a "cognitive bias" occurs when affective state influences aspects of cognition, such as judgement and attention. Animals in positive affective states make optimistically-biased decisions during ambiguous situations, judging the situation as if it will produce a positive outcome, and show less bias towards a perceived threat, responding in a less anxious and calm manner. Animals in negative affective states make pessimistically-biased decisions during ambiguous situations, judging the situation as if it will result in a negative outcome. Additionally, animals in negative affective states will bias their attention towards a perceived threat rather than alternative stimuli, responding in an anxious manner. Therefore, judgement and attention bias tests can be used to determine animal affective states. In Chapter 3, a judgement bias test was used to determine affective state of broiler chickens housed in either complex (perches, dust bath, pecking stones, and rotating enrichment objects) or barren (no enrichment) environments under either high or low stocking densities. Broilers housed in complex environments responded more optimistically during the judgement bias test than broilers from barren environments, indicating the former were in a positive affective state. Stocking density did not impact their responses in the judgement bias test, indicating that affective states were not impacted by that treatment. In Chapter 4, an attention bias test was used to determine level of anxiety and a tonic immobility test was used to determine fear in order to investigate affective state of broilers housed in the same conditions as described for Chapter 3. Broilers housed in complex environments were less anxious during the attention bias test than broilers from barren environments, indicating environmental complexity reduced anxiety in broilers. Stocking density did not impact anxiety. Broilers from high stocking density environments had shorter tonic immobility durations than broilers from low stocking density environments, suggesting the former were less fearful. Environmental complexity did not impact fearfulness. In Chapter 5, a judgement bias test was used to determine affective state of rainbow trout housed in either complex (shelter structure and artificial plants) or barren (no enrichment) tanks under either low or high stocking densities. Trout housed in high stocking density tanks responded optimistically during the judgement bias test, indicating they were in a more positive affective state compared to trout housed in low stocking density tanks. Environmental complexity did not impact their responses in the judgement bias test, indicating no effect of enrichments on affective states was found. These results indicate a beneficial relationship of a complex environment on broiler chicken affective state, observed through an optimistic judgement bias and reduced attention bias (anxiety) towards a perceived threat. Thus, providing a complex housing environment for broilers can improve their welfare and result in a positive affective state. Rainbow trout reared at the tested high density resulted in a positive affective state, although complexity did not benefit their welfare. Our results contribute much needed information on stocking densities to ensure fish welfare. Overall, environmental complexity, not stocking density, had a positive impact on broiler chicken affective states. Rainbow trout affective states were positively impacted by stocking density, but not environmental complexity. / Master of Science / Conventional housing of broiler chickens and rainbow trout (both raised for meat) causes concern for their welfare and affective states. Environmental conditions can greatly impact animals' affective states–their long-term emotional state, ranging from positive to negative. In barren environments at high stocking densities, broiler chickens and rainbow trout are prevented from showing normal behaviors and these conditions can compromise their affective state and welfare. By 'asking' chickens and trout whether the glass is half full or half empty, we can determine level of optimism or pessimism, and level of anxiety or calmness, therefore gaining a better understanding of their affective states. This can be done using a judgement bias test and attention bias test, where animal responses (optimism and anxiety) are recorded during ambiguous situations (judgement) and threatening situations (attention). Animals in positive affective states judge ambiguous situations optimistically (glass half full) and pay little attention towards perceived threats, while animals in negative affective states judge the same ambiguous situations pessimistically (glass half empty) and pay more attention towards perceived threats. In Chapter 3, responses to ambiguous situations were used to determine the affective state of broiler chickens housed in either enriched (perches, dust bath, pecking stones, rotating toys) or barren environments at either high or low stocking densities. Broiler chickens housed in enriched environments had an optimistic judgement bias of ambiguous situations (glass half full), suggesting they were in a more positive affective state compared to broilers housed in barren environments. Stocking density did not impact their level of optimism. In Chapter 4, responses to a perceived threat were used to determine level of anxiety and a tonic immobility test was used to determine fear of broilers housed under the same conditions as in Chapter 3. Broilers housed in enriched environments paid less attention to a perceived threat than broilers housed in barren environments, indicating the former were less anxious (glass half full) and in a positive affective state. Fear was not impacted by the tested enrichments, but birds kept under higher stocking densities did show reduced fear compared to birds in low-density environments. In Chapter 5, rainbow trout were housed in either enriched (shelter structure and artificial plants) or barren tanks at either high or low stocking densities. Affective state was evaluated through their responses to ambiguous situations. Trout housed in high stocking density environments had an optimistic judgement bias of ambiguous situations (glass half full), suggesting they were in a more positive affective state than trout housed in low stocking density environments. The enrichments did not impact their responses during the test, suggesting they did not impact fish optimism. These results indicate that an enriched environment improves broiler affective state and welfare compared to conventional housing conditions, the tested densities did not impact their welfare. Although an enriched environment did not positively impact responses of trout during ambiguous situations, our results show that housing rainbow trout in large groups results in a positive affective state and improved welfare status compared to housing trout in small groups. Overall, environmental enrichment, not stocking density, had a positive impact on broiler chicken affective states. Rainbow trout affective states were positively impacted by stocking density, but not environmental enrichment.

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.

The influence of biological supplement AEN 700 in broiler chicken fattening was traced in operating conditions of broiler houses Kladruby.This influence was analysed economically.Compared to year 2005 when the antibiotic stimulators of growth were used there are well-balanced zootechnical and economical results.The results of development confirmed that the biological supplement AEN 700 has minimally equivalent effect in production and in economical effect compared to antibiotic stimulators of growth.

Foram realizados dois experimentos de metabolismo para a determinação da energia metabolizável aparente (EMA), energia metabolizável aparente corrigida para nitrogênio (EMAn) e digestibilidade aparente (DG) de diferentes gorduras para as fases pré-inicial, inicial, crescimento e final de frangos de corte. Um terceiro experimento foi realizado para avaliar o ganho de peso, consumo de ração, conversão alimentar e viabilidade de frangos de corte alimentados com dietas suplementadas com gorduras com valores energéticos determinados no experimentos de metabolismo. Nos experimentos de metabolismo os tratamentos consistiram de uma dieta referência e 5 dietas obtidas pela substituição de 10%, peso por peso, da dieta referência pelas seguintes gorduras e suas misturas: óleo de soja (OS), óleo ácido (OA), óleo de vísceras de aves (OV), 50% de óleo de soja com 50% de óleo ácido (OS50/OA50), 50% de óleo de soja com 50% de óleo de vísceras de aves (OS50/OV50) no primeiro experimento e as misturas: 75% de óleo de vísceras de aves com 25% óleo soja (OV75/OS25), 75% óleo de vísceras de aves com 25% óleo ácido (OV75/OA25), 50% de óleo ácido com 50% óleo de vísceras de aves (OA50/OV50), 75% de óleo ácido com 25% óleo de vísceras de aves (OA75/OV25), 75% de óleo ácido com 25% de óleo de soja (OA75/OS25) no segundo experimento. A dieta referência era baseada em milho e farelo de soja, formuladas sem gordura suplementar. Em cada experimento foram realizados 4 ensaios correspondentes às fases de criação. Utilizaram-se 4 repetições por tratamento em delineamento inteiramente ao acaso. No primeiro experimento os valores de EMA, EMAn e DG do OA mostraram-se inferiores (p<0,05) às demais gorduras. A EMA, EMAn e a DG do OS50/OA50 e do OS50/OV50 não apresentaram diferenças (p>0,05) em relação ao OV e OS nas fases pré-inicial, inicial e crescimento, porém na fase final, essas misturas resultaram em energias metabolizáveis similares ao OV, menores que o OS e superiores ao OA. A DG das dietas com misturas de gordura não diferiu (p>0,05) das dietas com OS e OV em todas as fases estudadas. No experimento 2 os valores de EMA, EMAn e DG para as misturas OA75/OV25, OA75/SO25, OA50/OV50 foram inferiores as demais gorduras nas fases pré-inicial, inicial e crescimento. A EMA, EMAn e a DG do OV75/OS25 foram superiores nas fases pré-inicial, inicial e crescimento. Em ambos os experimentos, os valores de EMA e EMAn das gorduras na fase pré-inicial foram inferiores quando comparados às demais fases. No terceiro experimento utilizaram-se as mesmas fases de criação e os valores de EMAn determinados nos experimentos anteriores. Os tratamentos selecionados foram OA, OS, OV, 75OA/25OS, 50OA/50OS e 50OV/50OS, com 6 repetições e 40 aves por parcela, alimentadas com rações isoprotéicas e isoenergéticas a base de milho e farelo de soja. Foram determinados o desempenho, peso e rendimento da carcaça, peito, coxa, sobrecoxa, gordura abdominal e fígado. O OS resultou em inferior desempenho, peso da carcaça, peito, coxa e sobrecoxa em relação aos demais tratamentos. Não houve diferenças significativas entre os tratamentos no acúmulo de gordura, peso do fígado, rendimentos da carcaça e das partes. / Two metabolism trials were carried out to determine the apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) of fats and their mixtures. In trial 1 the treatments consisted of a basal diet and 5 diets obtained by substituting, weight by weight, 10% of the basal diets with the fat sources: soybean oil (SO), acidulated soapstock (AS), poultry offal fat (PF), 50% soybean oil and 50% acidulated soapstock (SO50/AS50), 50% soybean oil and 50% poultry offal fat (SO50/PF50). In trial 2, the following mixtures were fed: 75% poultry offal fat and 25% soybean oil (PF75/SO25), 75% poultry offal fat and 25% acidulated soapstock (PF75/AS25), 50% soapstock and 50% poultry offal fat (AS50/PF50), 75% acidulated soapstock and 25% poultry offal fat (AS75/PF25) and 75% acidulated soapstock and 25% soybean oil (AS75/SO25). The basal diet was based on corn and soybean meal, formulated with no added fat. Each treatment was replicated 4 times in a completely randomized design. In each trial there were 4 assays corresponding to the pre-starter (0-10 days), starter (11-21 days), grower (22-35 days) and finisher (36-42 days) phases. In trial 1, AME and AMEn values for AS were lower (p<0.05) than those for the other fats in all phases; this can be due to the elevated level of free fatty acids in AS. AME and AMEn of the mixture SO50/AS50, as well as the mixture (SO50/PF50), were not different from those of SO and PF in the pre-starter, starter and grower phases; however, in the finisher phase these mixtures resulted in metabolizable energy similar to PF (p>0.05), lower than SO and higher than AS (p<0.05). In trial 2, AME and AMEn values were lower in the pre-starter, starter and grower phases for the mixtures AS75/PF25, AS75/SO25 and AS50/SO50 (p<0.05). AME and AMEn were higher for PF75/SO25 in the pre-starter, starter and grower phases (p<0.05). In both trials the metabolizable energy was lower for birds in the pre-starter phase than in the other phases. In a performance trial diets were formulated using the AMEn of fats previously determined for pre-starter, starter, grower and finisher phases. Selected treatments were AS, SO, PF, AS75/SO25, AS50/SO50 and PF50/SO50 with 6 replicates and 40 birds per pen. Diets were isoproteic and isoenergetic. Growth performance and carcass and parts yield were determined. Treatments did not result in significant differences (p>0.05), except for SO which was inferior to the other treatments.

Doenças, como a enterite necrótica aviária (NE), têm se tornado reemergentes em função não apenas do sistema de criação intensivo de frangos de corte atualmente em uso, como também da restrição imposta ao uso dos aditivos antimicrobianos por diversos países, dentre os quais, aqueles da União Européia. A NE é uma doença que acomete aves de produção e seu agente etiológico primário é o Clostridium perfringens tipo A. Pouco se conhece a respeito dos mecanismos pelos quais o estresse modula o desenvolvimento da NE. O presente trabalho foi realizado para avaliar os efeitos do estresse por calor sobre o desenvolvimento da NE em frangos de corte. Empregou-se, para tal, modelos experimentais de NE em que se usou infecção isolada por C. perfringens e/ou em co-infecção com Eimeria spp. O estresse por calor foi aplicado de forma contínua ou intermitente em longo prazo. Foram propostos sete experimentos; em cinco deles os animais foram criados em câmaras isoladoras e, nos dois restantes, em galpões. Foram feitas avaliações da imunidade sistêmica, de órgãos linfoides secundários e do intestino delgado para determinar os efeitos imunomodulatórios da infecção e/ou do estresse por calor. Para caracterização dos efeitos neuroimunes, fizemos uma análise integrada dos achados imunes, de atividade do Sistema Nervoso Central e/ou de ativação do eixo hipotálamo-hipófise-adrenal (HPA). Foram utilizadas medidas quantitativas e semiquantitativas para avaliar os diferentes graus de lesão tecidual decorrentes do processo infeccioso e/ou parasitário com ou sem estresse por calor. Para analisar os efeitos do estresse no processo infeccioso/parasitário empregamos, também, cultivos microbiológicos e técnicas usadas para determinação da proliferação do C. perfringens e da Eimeria spp. Os resultados mostraram que o estresse por calor: reduziu a inflamação intestinal e o dano tecidual em modelo de NE empregando infecção isolada por C. perfringens preparada em caldo tioglicolato; reduziu a formação de centros germinais esplênicos e intestinais com consequente modulação da produção de imunoglobulinas séricas e secretórias; ativou núcleos do SNC relacionados á atividade do eixo HPA; ativou o eixo cérebro-intestinal; diminuiu a infecção intestinal por Eimeria spp., com consequente redução do desenvolvimento da NE e da lesão tecidual dela resultante; modulou a atividade de sistemas de neurotransmissão central relacionados com o comportamento das aves e ativação do eixo HPA; alterou o perfil neuroquímico cerebral quando em associação com a NE; facilitou o desenvolvimento da infecção por C. perfringens em animais não desafiados por fatores predisponentes da NE; reduziu a lesão tecidual no modelo de co-infecção por C. perfringens e Eimeria spp.; modulou o balanço de citocinas para um padrão Th2 no intestino dos animais infectados ou não; alterou as subpopulações de linfócitos esplênicos e circulantes, bem como a função proliferativa destas células e a resposta das mesmas à expressão de citocinas. Desta forma, concluímos que o estresse por calor e/ou inflamação intestinal de origem infecciosa ou química ativam o eixo HPA por mecanismo que envolve o eixo cérebro-intestinal, reduzindo os sinais clínicos da NE por interferir na patogênese do C. perfringens e da Eimeria spp / Diseases such as necrotic enteritis (NE) are coming back not only as a consequence of the intensive farming procedures now being used but also as a consequence of the restrictions imposed by the European Union countries to the use of antimicrobials as feed additives. NE is a disease that affects poultry production; its primary etiologic agent is Clostridium perfringens type A. Little is known about the mechanisms by which stress modulates the development of NE. Thus, to evaluate the effects of heat stress on NE development, sevenstudies were done using experimental models of NE that used C. perfringens infection per se or in combination with Eimeria spp. Heat stress was used throughout the experiments, being applied continuously or intermittently but always for long-term. Five experiments were performed using animals reared in isolator chambers and two others employing animals reared in sheds. Evaluations of systemic immunity, secondary lymphoid organs and small intestine portions were used to determine the immunomodulatory effects of the infections and/or of the heat stress. Neuroimmune effects were assessed using an integrative approach of the observed immune, Central Nervous System (CNS) and/or hypothalamic-pituitary-adrenal (HPA) axis changes. Quantitative and semi-quantitative techniques were utilized to measure and compare the different degrees of tissue damage resulting from the infectious processes in the presence and absence of heat stress. Microbiological techniques were also used to determine C. perfringens and Eimeria spp. proliferations. Results showed that heat stress: reduced intestinal inflammation and tissue damage in the NE model that used C. perfringens together with thioglycolate broth culture medium intake; reduced the formation of splenic and intestinal germinal centers with subsequent production of serum and secretory immunoglobulins; activated some brain areas related to animals behavior and HPA axis activity; modified the brain-gut axis relationship during NE development; reduced Eimeria spp. infection leading to a subsequent reduction in the NE development and in the scores of tissue injury; together with NE, modified neuronal brain-amine systems activity and, as a consequence, changed animals behavior, HPA axis activity and brain amine systems fuction within some brain areas; predisposed the birds to C. perfringens infection in the presence or absence of NE inducing factors; reduced the tissue damages observed in the course of C. perfringens and Eimeria spp.co-infection; modulated cytokines to a Th2 pattern in animals infected or not; altered the splenic and peripheral blood lymphocytes subpopulations and, changed the proliferative function of immune cells and cytokine expression.Thus, we conclude that the heat stress and/or intestinal inflammation of infectious or chemical origin activate the HPA axis by a mechanism involving the brain-gut axis, reducing the clinical signs of NE by interfering in the pathogenesis of C. perfringens and Eimeria spp

Orientador: Nilva Kazue Sakomura / Banca: Elisabeth Gonzales / Banca: Renato Luis Furlan / Banca: Alice Eiko Murakami / Banca: Francisco Ernesto Moreno Bernal / Resumo: Com objetivo determinar os parâmetros de crescimento do peso vivo e da ave depenada, das penas e componentes químicos corporais, das partes, dos órgãos e tecidos de frangos de corte, machos e fêmeas das linhagens Ross e Cobb, foram utilizados 1920 pintos criados em galpão alojados em boxes. O delineamento foi inteiramente casualizado em esquema fatorial 2x2 (linhagens e sexo), 4 repetições de 120 aves cada. Foi avaliado o crescimento das aves depenadas e das penas, das partes e dos órgãos, dos músculos, ossos e peles. Foram realizados abates semanais até 56 dias de idade, após jejum de 24 horas. As aves foram pesadas para obtenção do peso de jejum, um grupo de aves foram depenados para obter o peso de penas, e as demais aves foram evisceradas e realizadas os cortes para avaliação do desenvolvimento das partes e órgãos. Após, foram pesadas, identificadas e congeladas. Posteriormente, as amostras foram moídas, liofilizadas e encaminhadas para análises de matéria seca, nitrogênio, extrato etéreo e cinzas. Foram elaboradas curvas e taxas de crescimento através da equação de Gompertz. As aves Cobb foram mais precoces no crescimento e deposição de proteína e cinzas corporais, na deposição de proteína, gordura e água das penas, na taxa de crescimento e deposição de nutrientes da coxa, dorso, cabeça, proventrículo e no crescimento do intestino. As aves Ross apresentaram maior potencial de crescimento de asa, pescoço, sobrecoxa e pés, e foram mais precoces no crescimento das penas, do fígado e deposição de água e cinzas no fígado. Houve semelhança entre as linhagens para peso do músculo, crescimento e deposição de nutrientes para o peito e coração e no peso e proteína dos ossos. / Abstract: The objective of this study was determine the growth parameters of the live weight, of feathers, of parts, organs and tissues and body chemical components strains chickens, males and females Cobb and Ross broilers. Were used 1920 chicks raised in boxes from 1 to 56 days of age, distributed randomly in a factorial model (2 strains x 2 sex), with 4 replicate pens of 120 birds. The birds were fed ad libitum with diets formulated according to requirements for each age phase. The birds were weight and four birds of each group were slaughtered weekly. Afther 24 hours of fasting, the birds were slaughtered to determined body, parts, organs, tissues weight and nutrients deposition. Thereafther, samples were freeze-fried to be analized for dry matter, protein, ash and fat. The parameters of weight and in nutrient depositions obtained weekly were adjusted by the Gompertz equation in order to estimate the growth parameters Wt= Wm exp(-exp(-B(t-t))). The growth and body nutrients deposition rates were determined by derived of the equations. Cobb broilers were more precocious in growth and of body protein and ash deposition than Ross. The deposition of protein, fat and water feather, in growth rate and depositions of nutrients in the thigh, dorsum, head and proventriculum and intestine were higher compared to Ross. The of Ross boilers was bigger than Cobb wing, neck, drumstick and feet growth potential. The Ross strains were more precocious in the growth of leg, liver and depositions of water and ash in the liver. The strains had similarity growth potencial of muscle and nutrients deposition in the breast, heart and bones. / Doutor

Doenças, como a enterite necrótica aviária (NE), têm se tornado reemergentes em função não apenas do sistema de criação intensivo de frangos de corte atualmente em uso, como também da restrição imposta ao uso dos aditivos antimicrobianos por diversos países, dentre os quais, aqueles da União Européia. A NE é uma doença que acomete aves de produção e seu agente etiológico primário é o Clostridium perfringens tipo A. Pouco se conhece a respeito dos mecanismos pelos quais o estresse modula o desenvolvimento da NE. O presente trabalho foi realizado para avaliar os efeitos do estresse por calor sobre o desenvolvimento da NE em frangos de corte. Empregou-se, para tal, modelos experimentais de NE em que se usou infecção isolada por C. perfringens e/ou em co-infecção com Eimeria spp. O estresse por calor foi aplicado de forma contínua ou intermitente em longo prazo. Foram propostos sete experimentos; em cinco deles os animais foram criados em câmaras isoladoras e, nos dois restantes, em galpões. Foram feitas avaliações da imunidade sistêmica, de órgãos linfoides secundários e do intestino delgado para determinar os efeitos imunomodulatórios da infecção e/ou do estresse por calor. Para caracterização dos efeitos neuroimunes, fizemos uma análise integrada dos achados imunes, de atividade do Sistema Nervoso Central e/ou de ativação do eixo hipotálamo-hipófise-adrenal (HPA). Foram utilizadas medidas quantitativas e semiquantitativas para avaliar os diferentes graus de lesão tecidual decorrentes do processo infeccioso e/ou parasitário com ou sem estresse por calor. Para analisar os efeitos do estresse no processo infeccioso/parasitário empregamos, também, cultivos microbiológicos e técnicas usadas para determinação da proliferação do C. perfringens e da Eimeria spp. Os resultados mostraram que o estresse por calor: reduziu a inflamação intestinal e o dano tecidual em modelo de NE empregando infecção isolada por C. perfringens preparada em caldo tioglicolato; reduziu a formação de centros germinais esplênicos e intestinais com consequente modulação da produção de imunoglobulinas séricas e secretórias; ativou núcleos do SNC relacionados á atividade do eixo HPA; ativou o eixo cérebro-intestinal; diminuiu a infecção intestinal por Eimeria spp., com consequente redução do desenvolvimento da NE e da lesão tecidual dela resultante; modulou a atividade de sistemas de neurotransmissão central relacionados com o comportamento das aves e ativação do eixo HPA; alterou o perfil neuroquímico cerebral quando em associação com a NE; facilitou o desenvolvimento da infecção por C. perfringens em animais não desafiados por fatores predisponentes da NE; reduziu a lesão tecidual no modelo de co-infecção por C. perfringens e Eimeria spp.; modulou o balanço de citocinas para um padrão Th2 no intestino dos animais infectados ou não; alterou as subpopulações de linfócitos esplênicos e circulantes, bem como a função proliferativa destas células e a resposta das mesmas à expressão de citocinas. Desta forma, concluímos que o estresse por calor e/ou inflamação intestinal de origem infecciosa ou química ativam o eixo HPA por mecanismo que envolve o eixo cérebro-intestinal, reduzindo os sinais clínicos da NE por interferir na patogênese do C. perfringens e da Eimeria spp / Diseases such as necrotic enteritis (NE) are coming back not only as a consequence of the intensive farming procedures now being used but also as a consequence of the restrictions imposed by the European Union countries to the use of antimicrobials as feed additives. NE is a disease that affects poultry production; its primary etiologic agent is Clostridium perfringens type A. Little is known about the mechanisms by which stress modulates the development of NE. Thus, to evaluate the effects of heat stress on NE development, sevenstudies were done using experimental models of NE that used C. perfringens infection per se or in combination with Eimeria spp. Heat stress was used throughout the experiments, being applied continuously or intermittently but always for long-term. Five experiments were performed using animals reared in isolator chambers and two others employing animals reared in sheds. Evaluations of systemic immunity, secondary lymphoid organs and small intestine portions were used to determine the immunomodulatory effects of the infections and/or of the heat stress. Neuroimmune effects were assessed using an integrative approach of the observed immune, Central Nervous System (CNS) and/or hypothalamic-pituitary-adrenal (HPA) axis changes. Quantitative and semi-quantitative techniques were utilized to measure and compare the different degrees of tissue damage resulting from the infectious processes in the presence and absence of heat stress. Microbiological techniques were also used to determine C. perfringens and Eimeria spp. proliferations. Results showed that heat stress: reduced intestinal inflammation and tissue damage in the NE model that used C. perfringens together with thioglycolate broth culture medium intake; reduced the formation of splenic and intestinal germinal centers with subsequent production of serum and secretory immunoglobulins; activated some brain areas related to animals behavior and HPA axis activity; modified the brain-gut axis relationship during NE development; reduced Eimeria spp. infection leading to a subsequent reduction in the NE development and in the scores of tissue injury; together with NE, modified neuronal brain-amine systems activity and, as a consequence, changed animals behavior, HPA axis activity and brain amine systems fuction within some brain areas; predisposed the birds to C. perfringens infection in the presence or absence of NE inducing factors; reduced the tissue damages observed in the course of C. perfringens and Eimeria spp.co-infection; modulated cytokines to a Th2 pattern in animals infected or not; altered the splenic and peripheral blood lymphocytes subpopulations and, changed the proliferative function of immune cells and cytokine expression.Thus, we conclude that the heat stress and/or intestinal inflammation of infectious or chemical origin activate the HPA axis by a mechanism involving the brain-gut axis, reducing the clinical signs of NE by interfering in the pathogenesis of C. perfringens and Eimeria spp

Foram realizados dois experimentos de metabolismo para a determinação da energia metabolizável aparente (EMA), energia metabolizável aparente corrigida para nitrogênio (EMAn) e digestibilidade aparente (DG) de diferentes gorduras para as fases pré-inicial, inicial, crescimento e final de frangos de corte. Um terceiro experimento foi realizado para avaliar o ganho de peso, consumo de ração, conversão alimentar e viabilidade de frangos de corte alimentados com dietas suplementadas com gorduras com valores energéticos determinados no experimentos de metabolismo. Nos experimentos de metabolismo os tratamentos consistiram de uma dieta referência e 5 dietas obtidas pela substituição de 10%, peso por peso, da dieta referência pelas seguintes gorduras e suas misturas: óleo de soja (OS), óleo ácido (OA), óleo de vísceras de aves (OV), 50% de óleo de soja com 50% de óleo ácido (OS50/OA50), 50% de óleo de soja com 50% de óleo de vísceras de aves (OS50/OV50) no primeiro experimento e as misturas: 75% de óleo de vísceras de aves com 25% óleo soja (OV75/OS25), 75% óleo de vísceras de aves com 25% óleo ácido (OV75/OA25), 50% de óleo ácido com 50% óleo de vísceras de aves (OA50/OV50), 75% de óleo ácido com 25% óleo de vísceras de aves (OA75/OV25), 75% de óleo ácido com 25% de óleo de soja (OA75/OS25) no segundo experimento. A dieta referência era baseada em milho e farelo de soja, formuladas sem gordura suplementar. Em cada experimento foram realizados 4 ensaios correspondentes às fases de criação. Utilizaram-se 4 repetições por tratamento em delineamento inteiramente ao acaso. No primeiro experimento os valores de EMA, EMAn e DG do OA mostraram-se inferiores (p<0,05) às demais gorduras. A EMA, EMAn e a DG do OS50/OA50 e do OS50/OV50 não apresentaram diferenças (p>0,05) em relação ao OV e OS nas fases pré-inicial, inicial e crescimento, porém na fase final, essas misturas resultaram em energias metabolizáveis similares ao OV, menores que o OS e superiores ao OA. A DG das dietas com misturas de gordura não diferiu (p>0,05) das dietas com OS e OV em todas as fases estudadas. No experimento 2 os valores de EMA, EMAn e DG para as misturas OA75/OV25, OA75/SO25, OA50/OV50 foram inferiores as demais gorduras nas fases pré-inicial, inicial e crescimento. A EMA, EMAn e a DG do OV75/OS25 foram superiores nas fases pré-inicial, inicial e crescimento. Em ambos os experimentos, os valores de EMA e EMAn das gorduras na fase pré-inicial foram inferiores quando comparados às demais fases. No terceiro experimento utilizaram-se as mesmas fases de criação e os valores de EMAn determinados nos experimentos anteriores. Os tratamentos selecionados foram OA, OS, OV, 75OA/25OS, 50OA/50OS e 50OV/50OS, com 6 repetições e 40 aves por parcela, alimentadas com rações isoprotéicas e isoenergéticas a base de milho e farelo de soja. Foram determinados o desempenho, peso e rendimento da carcaça, peito, coxa, sobrecoxa, gordura abdominal e fígado. O OS resultou em inferior desempenho, peso da carcaça, peito, coxa e sobrecoxa em relação aos demais tratamentos. Não houve diferenças significativas entre os tratamentos no acúmulo de gordura, peso do fígado, rendimentos da carcaça e das partes. / Two metabolism trials were carried out to determine the apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) of fats and their mixtures. In trial 1 the treatments consisted of a basal diet and 5 diets obtained by substituting, weight by weight, 10% of the basal diets with the fat sources: soybean oil (SO), acidulated soapstock (AS), poultry offal fat (PF), 50% soybean oil and 50% acidulated soapstock (SO50/AS50), 50% soybean oil and 50% poultry offal fat (SO50/PF50). In trial 2, the following mixtures were fed: 75% poultry offal fat and 25% soybean oil (PF75/SO25), 75% poultry offal fat and 25% acidulated soapstock (PF75/AS25), 50% soapstock and 50% poultry offal fat (AS50/PF50), 75% acidulated soapstock and 25% poultry offal fat (AS75/PF25) and 75% acidulated soapstock and 25% soybean oil (AS75/SO25). The basal diet was based on corn and soybean meal, formulated with no added fat. Each treatment was replicated 4 times in a completely randomized design. In each trial there were 4 assays corresponding to the pre-starter (0-10 days), starter (11-21 days), grower (22-35 days) and finisher (36-42 days) phases. In trial 1, AME and AMEn values for AS were lower (p<0.05) than those for the other fats in all phases; this can be due to the elevated level of free fatty acids in AS. AME and AMEn of the mixture SO50/AS50, as well as the mixture (SO50/PF50), were not different from those of SO and PF in the pre-starter, starter and grower phases; however, in the finisher phase these mixtures resulted in metabolizable energy similar to PF (p>0.05), lower than SO and higher than AS (p<0.05). In trial 2, AME and AMEn values were lower in the pre-starter, starter and grower phases for the mixtures AS75/PF25, AS75/SO25 and AS50/SO50 (p<0.05). AME and AMEn were higher for PF75/SO25 in the pre-starter, starter and grower phases (p<0.05). In both trials the metabolizable energy was lower for birds in the pre-starter phase than in the other phases. In a performance trial diets were formulated using the AMEn of fats previously determined for pre-starter, starter, grower and finisher phases. Selected treatments were AS, SO, PF, AS75/SO25, AS50/SO50 and PF50/SO50 with 6 replicates and 40 birds per pen. Diets were isoproteic and isoenergetic. Growth performance and carcass and parts yield were determined. Treatments did not result in significant differences (p>0.05), except for SO which was inferior to the other treatments.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-24T13:37:53Z No. of bitstreams: 1 2011- Veronica da Silva Cardoso.pdf: 2067813 bytes, checksum: a52c401412243d162e7030dda12cdf48 (MD5) / Made available in DSpace on 2016-08-24T13:37:53Z (GMT). No. of bitstreams: 1 2011- Veronica da Silva Cardoso.pdf: 2067813 bytes, checksum: a52c401412243d162e7030dda12cdf48 (MD5) Previous issue date: 2011-04-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Piperine interference (amide extracted from black pepper) added to the diet of broiler chickens experimentally intoxicated by aflatoxin B1 (mycotoxin of great importance in the poultry sector) and it?s chemoprotective capacity were the main goal of this work. The experiment was divided into two assays: (i) The first assay was carried out to determine the effects of different concentrations of piperine (0, 60, 120, 180 ppm) and it?s possible toxicity in broiler chickens diets. Ninety six male chicks (Cobb), seven days old were used, being randomly allocated into four experimental groups (n=24) during 35 consecutive days. The following parameters were evaluated: biochemical, hematological, histopathological (proventriculus, gizzard, liver, kidney), histomorphometric (small intestine) and zootecnic. The concentration of 60 ppm of piperine in the diet was safe for broilers, showing better performance of broilers on period from 36 to 42 days old. The concentration of 180 ppm caused leukopenia and concentrations of 120 and 180 ppm was observed decrease in the number of heterophils and monocytes. Hepatotoxicity was observed by elevated AST enzyme activity, histopathological changes and decreased absorption surface in the segments (jejunum and ileum) of small intestine were observed for both 120 and 180 ppm concentrations. (ii) In the second assay, 60 broilers with nine days old divided into four groups: control, piperine (60 ppm added to diet), aflatoxin B1 (0.5 mg of aflatoxin B1.Kg-1 of body weight, orally) and piperine associated aflatoxin B1, were evaluated by effect chemoprotector of piperine against toxics effects of aflatoxin B1 being evaluated for zootecnic, biochemical, histopathological and histomorphometric parameters, toxic heterophils in peripheral blood and genotoxic by comet assay and micronucleus were also determined. No changes in the performance parameters were observed after this experiment. Broiler chickens intoxicated with AFB1 (0.5 mg of aflatoxin B1.kg-1 of body weight ) showed: decreased body weight gain and increased feed conversion; reduced carcass and cuts yields; liver toxicity, with increased relative weight of the liver and heart, macroscopic variations of hepatic parenchyma and increase of liver enzymes activity; kidney enzymes increase without evidence of renal tissue damage macroscopic or microscopic; leukopenia with significant reduction of lymphocytes and heterophils; reduction in absorptive surface due to the reduction of the length and width of the villi of all studied segments of small intestine; presence of toxic heterophils. The cytotoxic and genotoxic effects of aflatoxin B1 described above were significantly reduced or absent in the group of broiler intoxicated with aflatoxin B1 and fed with with piperine. No significant difference between piperine associated aflatoxin B1 in control and piperine groups were observed. The addition of 60 ppm of piperine in the diet of broiler chickens was safe, promoting beneficial effect both in zootecnic parameters and in poultry health, preventing toxic effects of aflatoxin B1in broiler chickens. / A interfer?ncia da piperina (amida extra?da da pimenta do reino) adicionada ? ra??o de frangos de corte intoxicados experimentalmente por aflatoxina B1 (micotoxina de grande relev?ncia no setor av?cola) e sua capacidade quimioprotetora foram o principal objetivo deste trabalho. O experimento foi dividido em dois ensaios: (i) O primeiro ensaio foi realizado para determinar os efeitos de diferentes concentra??es de piperina (0, 60, 120 e 180 ppm) foram avaliados e sua poss?vel toxicidade. Noventa e seis pintos (Cobb), com 7 dias de idade foram divididos aleatoriamente em 4 grupos (n=24), por 35 dias consecutivos. Os par?metros avaliados foram: hematol?gicos, bioqu?micos, histopatol?gicos (proventr?culo, moela, f?gado e rim), histomorfom?trico (intestino delgado) e par?metros zoot?cnicos. A concentra??o de 60 ppm de piperina adicionada ? ra??o foi segura para frangos de corte, tendo ainda resultado em melhor desempenho dos frangos na fase final (36-42 dias de idade). A concentra??o de 180 ppm promoveu leucopenia e nas concentra??es de 120 e 180 ppm foi observada diminui??o do n?mero de heter?filos e mon?citos; hepatotoxicidade, com eleva??o da enzima AST e altera??es histopatol?gicas em ambas as concentra??es; diminui??o da superf?cie de absor??o nos segmentos (jejuno e ?leo) do intestino delgado, por?m, sem altera??o dos par?metros zoot?cnicos. (ii) Para o segundo ensaio com a concentra??o de 60ppm de piperina: 60 frangos com 9 dias de idade, foram divididos em 4 grupos (n=15): grupo controle, grupo aflatoxina B1 (0,5 mg aflatoxina B1.kg-1 de peso vivo por via oral), grupo piperina (60 ppm adicionada ? ra??o) e grupo piperina associada a aflatoxina B1, determinando-se a capacidade quimioprotetora da piperina sendo avaliados os par?metros zoot?cnicos, hematol?gicos, bioqu?micos, histopatol?gicos, histomorfom?tricos, os efeitos genot?xicos da aflatoxina B1 pelo teste do cometa e do micron?cleo, presen?a de heter?filos t?xicos no sangue perif?rico. Os frangos intoxicados com aflatoxina B1 (0,5 mg de aflatoxina B1.Kg-1 de peso vivo) apresentaram: diminui??o do ganho m?dio de peso e piora da convers?o alimentar; diminui??o do rendimento de carca?a e cortes; hepatotoxicidade, com aumento de peso relativo do f?gado e cora??o, varia??es macrosc?picas do par?nquima hep?tico e eleva??o das enzimas hep?ticas; aumento das enzimas renais, sem evid?ncia de les?es macrosc?picas e microsc?picas no tecido renal; leucopenia, com diminui??o significativa de linf?citos e heter?filos; diminui??o da superf?cie de absor??o em fun??o da redu??o do comprimento e largura das vilosidades de todos os segmentos estudados do intestino delgado; presen?a de heter?filos t?xicos. Os efeitos citot?xicos e genot?xicos da aflatoxina B1 foram significativamente reduzidos ou ausentes no grupo piperina associada a aflatoxina B1, sem diferen?a significativa entre o grupo controle e piperina. A ra??o de frangos de corte com 60 ppm de piperina foi segura, promovendo efeito ben?fico tanto nos par?metros zoot?cnicos avaliados, como na sanidade av?cola, por impedir os efeitos t?xicos da aflatoxina B1 em frangos de corte.