Immunological indices of Giant African Land snails (Archachatina marginata) improved with fixed dose of vitamin C during acute heat stress

The study determined immunological indices of Giant African Land snail (Archachatina marginata) improved with fixed dose of vitamin C under acute heat stress (AHS). Prior to the AHS, vitamin C was administered for four weeks to two treatment groups, while other two treatment groups were not. Each treatment was monitored, haemolymph collected at 0, 30 and 60 minutes exposure times. Immunological cytokines: interferon gamma (IFN-γ) and interleukin 2 (IL-2); and total haemocyte counts (THC) were determined. Under AHS, vitamin C elevated (p <0.05) IFN-γ production (606.33 ± 302.86) compared to other groups with or without vitamin C administration (7.20 ± 1.58 vs. 73.20 ± 32.23 vs. 7.80 ± 1.36). IL-2 was not affected (p >0.05) by vitamin C under AHS. Highest (p <0.05) THC values was obtained with vitamin C administration under AHS, but reduced under no AHS. Exposure time affected (p <0.05) IFN-γ production and THC values, but not IL-2 (p >0.05). With fixed dose of vitamin C and exposure time, highest (p <0.05) IFN-γ values were obtained under AHS with vitamin C administration at 30 minutes and at 60 minutes in THC, compared to other groups. The study concluded that fixed dose of vitamin C at 150 mg kg-1 of feed was appropriate under AHS to boost the immune system of the animals.(AU)

Cumulative effect of different acute stressors on physiological and hormonal responses and milk yield in lactating Saanen goats / Efeito cumulativo de diferentes estressores agudos sobre as respostas fisiológicas, hormonais e produção de leite de cabras Saanen em lactação

This study addresses the hypothesis that acute stress can cumulatively cause a decrease in milk yield in Saanen goats. In fact, dairy animals are subject to several environmental and management challenges that may cause acute stress during the same lactation. However, the cumulative effect of acute stress on milk yield remains unclear. Thus, the objective of this study was to evaluate the effects of different acute stressors on milk yield and milk quality in goats. Thirty Saanen goats were either maintained on their usual routine and comfort conditions (control group) or subjected to different environmental stressors (heat stress, adrenocorticotropic hormone [ACTH] administration, hoof care, and rain). These stressful challenges were performed sequentially, one challenge per day, on four consecutive days to evaluate the influence of the challenge on milk yield and milk quality. The acute stress imposed on goats caused significant changes in respiratory rate, rectal temperature, cortisol, insulin, triiodothyronine, insulin-like growth factor 1, and glucose concentrations when compared to the control group. Although these acute-stress-triggered physiological responses are fundamental to restoring homeostasis, the cumulative effects of different imposed challenges caused a change in hormone release, an increase in somatic cell count (SCC), and a decrease in milk yield. In this context, the results of this study indicate that farmers should avoid concurrently subjecting goats to management and environmental challenges that can induce acute stress because these stressors have a negative and cumulative impact on SCC and milk yield.(AU)

Este estudo aborda a hipótese de que o estresse agudo pode causar cumulativamente uma diminuição na produção de leite de cabras Saanen. De fato, os animais leiteiros estão sujeitos a vários desafios ambientais e de manejo que podem causar estresse agudo durante a mesma lactação. No entanto, o efeito cumulativo do estresse agudo na produção de leite ainda não está claro. Assim, o objetivo deste estudo foi avaliar os efeitos de diferentes estressores agudos na produção e qualidade de leite de cabras Saanen. Trinta cabras Saanen foram mantidas em sua rotina habitual e condições de conforto (grupo controle) ou submetidas a diferentes estressores ambientais (estresse por calor, administração de hormônio adrenocorticotrófico [ACTH], cuidados com os cascos e chuva). Esses desafios estressantes foram realizados sequencialmente, um desafio por dia, em quatro dias consecutivos para avaliar a influência do desafio na produção e qualidade do leite. O estresse agudo imposto as cabras causou alterações significativas na frequência respiratória, temperatura retal, cortisol, insulina, triiodotironina, fator de crescimento semelhante à insulina 1 e concentrações de glicose quando comparado ao grupo controle. Embora essas respostas fisiológicas desencadeadas pelo estresse agudo sejam fundamentais para restaurar a homeostase, os efeitos cumulativos de diferentes desafios impostos causaram uma mudança na liberação de hormônios, um aumento na contagem de células somáticas (CCS) e uma diminuição na produção de leite. Neste contexto, os resultados deste estudo indicam que os produtores devem evitar submeter as cabras concomitantemente a desafios de manejo e ambientais que possam induzir estresse agudo, pois esses estressores têm impacto negativo e cumulativo na CCS e na produção de leite.(AU)

Impact of an acute heat shock during in vitro maturation on interleukin 6 and its associated receptor component transcripts in bovine cumulus-oocyte complexes

An acute heat stress event after the LH surge increased interleukin 6 (IL6) levels in the follicular fluid of the ovulatory follicle in hyperthermic cows. To examine direct consequences of a physiologically-relevant elevated temperature (41.0°C) on the cumulus-oocyte complex (COC), IL6 transcript abundance and related receptor components were evaluated throughout in vitro maturation. Heat-induced increases in IL6 were first noted at 4 hours of in vitro maturation (hIVM); peak levels occurred at 4.67 versus 6.44 hIVM for 41.0 and 38.5°C COCs, respectively (SEM = 0.23; P < 0.001). Peak IL6ST levels occurred at 6.95 versus 8.29 hIVM for 41.0 and 38.5°C, respectively (SEM = 0.23; P < 0.01). Transcript for LIF differed over time (P < 0.0001) but was not affected by 41.0°C exposure. Blastocyst development after performing IVF was not affected by 41.0°C exposure for 4 or 6 h. When limiting analysis to when IL6 was temporally produced, progesterone levels were only impacted by time and temperature (no interaction). Heat-induced shift in the temporal production of IL6 and IL6ST along with its impact on progesterone likely cooperate in heat-induced hastening of meiotic progression described by others.

Impact of an acute heat shock during in vitro maturation on interleukin 6 and its associated receptor component transcripts in bovine cumulus-oocyte complexes

An acute heat stress event after the LH surge increased interleukin 6 (IL6) levels in the follicular fluid of the ovulatory follicle in hyperthermic cows. To examine direct consequences of a physiologically-relevant elevated temperature (41.0°C) on the cumulus-oocyte complex (COC), IL6 transcript abundance and related receptor components were evaluated throughout in vitro maturation. Heat-induced increases in IL6 were first noted at 4 hours of in vitro maturation (hIVM); peak levels occurred at 4.67 versus 6.44 hIVM for 41.0 and 38.5°C COCs, respectively (SEM = 0.23; P < 0.001). Peak IL6ST levels occurred at 6.95 versus 8.29 hIVM for 41.0 and 38.5°C, respectively (SEM = 0.23; P < 0.01). Transcript for LIF differed over time (P < 0.0001) but was not affected by 41.0°C exposure. Blastocyst development after performing IVF was not affected by 41.0°C exposure for 4 or 6 h. When limiting analysis to when IL6 was temporally produced, progesterone levels were only impacted by time and temperature (no interaction). Heat-induced shift in the temporal production of IL6 and IL6ST along with its impact on progesterone likely cooperate in heat-induced hastening of meiotic progression described by others.(AU)

Techniques to Minimize the Effects of Acute Heat Stress or Chronic in Broilers

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.(AU)

Techniques to Minimize the Effects of Acute Heat Stress or Chronic in Broilers

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.

Efeito do estresse térmico calórico agudo e crônico sobre a qualidade oocitária de bovinos de raças adaptadas / Effect of acute and chronic caloric heat stress on oocyte quality of adapted breeds cattle

Nos trópicos, o uso de raças adaptadas tem sido uma estratégia para minimizar o efeito do estresse térmico calórico (ETC). No entanto, faltam informações que quantifiquem o estresse e o seu efeito sobre a reprodução dessas raças. O objetivo deste estudo foi avaliar a qualidade do oócito recuperado e alguns parâmetros fisiológicos indicadores de ETC em bovinos de raças adaptadas. Animais Bos taurus x Bos indicus (n=6) e Bos taurus (raça Pantaneira; n=12), localizados na região de transição entre o Cerrado e o Pantanal brasileiro, foram submetidos à aspiração folicular guiada por ultrassonografia (OPU) em diferentes condições climáticas. Foram realizadas oito sessões de OPU, com intervalo mínimo de sete dias e máximo de 54 dias entre as coletas. Para caracterização climática, foi realizado o cálculo do índice de temperatura e umidade (ITU). Foram quantificados os ITUs do dia da OPU, sete dias antes e 60 dias antes de cada sessão. Os parâmetros fisiológicos e a viabilidade oocitária de fêmeas das raças Girolando e Pantaneira não foram afetados negativamente por ITUs entre 72 e 78. O ETC crônico (60 dias) parece afetar a viabilidade oocitária de doadoras na raça Pantaneira quando ITU é superior a 75.(AU)

In tropical regions, the use of adapted breeds has been a strategy to minimize the effect of heat stress (HS) in cattle. However, information quantifying stress and its effect on reproduction of these breeds is lacking. The aim of this study was to evaluate the quality of the recovered oocyte and some physiological parameters that indicate HS in adapted breed. Bos taurus x Bos indicus (n=6) and Pantaneira (n=12) cows, located in the transition region between Cerrado and Brazilian Pantanal, underwent follicular aspiration guided by ultrasound (OPU) in different weather conditions. Eight sessions of OPU were carried out, with a minimum interval of 7 days and maximum 54 days between sessions. For weather characterization, the temperature and humidity index (THI) was calculated. THI of the day of OPU, 7 days before and 60 days before each session were calculated. The physiological parameters and oocyte viability of Girolando and Pantaneira cows were not negatively influenced under ITU between 72 and 78. The chronic HS (60 days)may affect the oocyte viability of Pantaneira donors when ITU is over 75.(AU)

Efeito do estresse térmico calórico agudo e crônico sobre a qualidade oocitária de bovinos de raças adaptadas / Effect of acute and chronic caloric heat stress on oocyte quality of adapted breeds cattle

Nos trópicos, o uso de raças adaptadas tem sido uma estratégia para minimizar o efeito do estresse térmico calórico (ETC). No entanto, faltam informações que quantifiquem o estresse e o seu efeito sobre a reprodução dessas raças. O objetivo deste estudo foi avaliar a qualidade do oócito recuperado e alguns parâmetros fisiológicos indicadores de ETC em bovinos de raças adaptadas. Animais Bos taurus x Bos indicus (n=6) e Bos taurus (raça Pantaneira; n=12), localizados na região de transição entre o Cerrado e o Pantanal brasileiro, foram submetidos à aspiração folicular guiada por ultrassonografia (OPU) em diferentes condições climáticas. Foram realizadas oito sessões de OPU, com intervalo mínimo de sete dias e máximo de 54 dias entre as coletas. Para caracterização climática, foi realizado o cálculo do índice de temperatura e umidade (ITU). Foram quantificados os ITUs do dia da OPU, sete dias antes e 60 dias antes de cada sessão. Os parâmetros fisiológicos e a viabilidade oocitária de fêmeas das raças Girolando e Pantaneira não foram afetados negativamente por ITUs entre 72 e 78. O ETC crônico (60 dias) parece afetar a viabilidade oocitária de doadoras na raça Pantaneira quando ITU é superior a 75.(AU)

In tropical regions, the use of adapted breeds has been a strategy to minimize the effect of heat stress (HS) in cattle. However, information quantifying stress and its effect on reproduction of these breeds is lacking. The aim of this study was to evaluate the quality of the recovered oocyte and some physiological parameters that indicate HS in adapted breed. Bos taurus x Bos indicus (n=6) and Pantaneira (n=12) cows, located in the transition region between Cerrado and Brazilian Pantanal, underwent follicular aspiration guided by ultrasound (OPU) in different weather conditions. Eight sessions of OPU were carried out, with a minimum interval of 7 days and maximum 54 days between sessions. For weather characterization, the temperature and humidity index (THI) was calculated. THI of the day of OPU, 7 days before and 60 days before each session were calculated. The physiological parameters and oocyte viability of Girolando and Pantaneira cows were not negatively influenced under ITU between 72 and 78. The chronic HS (60 days)may affect the oocyte viability of Pantaneira donors when ITU is over 75.(AU)

Upregulation of tlr4 mrna expression levels in broiler chickens under acute heat stress

Toll-like receptors (TLRs) are well-characterized in mice and rats, but little is known on their role in broiler chickens during acute heat stress (AHS). The aim of the present study was to estimate the change in TLR4 mRNA expression in the liver, kidney's pleen, heart, and small intestine of broiler chickens under AHS. A total of 240 healthy Arbor Acres (AA) broiler chickens were randomly divided into four groups: control group (22±1°C; 0h), HS2, HS5 and HS10 (38±1°C; 2h, 5h and 10h of heat stress, respectively). As AHS duration increased, TLR4 mRNA expression slightly decreased at HS2 and HS5, but was dramatically elevated in HS10 (p 0.001) compared with the control group in the small intestine, as well as in the spleen at HS2 (p=0.001) and HS10 (p 0.001). The mRNA expression levels of TLR4 significantly increased in the liver, heart, and kidneys (p 0.001) at HS10, and in the kidneys at HS5 (p=0.003). It is found that TLR4 mRNA expression at HS10 in different organs was significantly higher (p 0.001) compared with HS2 and HS5. The results of the present study suggest that AHS may modulate the functional responses of the liver, kidney, spleen, heart, and small intestine of broilers by regulating TLR4 mRNA expression.

Upregulation of tlr4 mrna expression levels in broiler chickens under acute heat stress

Toll-like receptors (TLRs) are well-characterized in mice and rats, but little is known on their role in broiler chickens during acute heat stress (AHS). The aim of the present study was to estimate the change in TLR4 mRNA expression in the liver, kidney's pleen, heart, and small intestine of broiler chickens under AHS. A total of 240 healthy Arbor Acres (AA) broiler chickens were randomly divided into four groups: control group (22±1°C; 0h), HS2, HS5 and HS10 (38±1°C; 2h, 5h and 10h of heat stress, respectively). As AHS duration increased, TLR4 mRNA expression slightly decreased at HS2 and HS5, but was dramatically elevated in HS10 (p 0.001) compared with the control group in the small intestine, as well as in the spleen at HS2 (p=0.001) and HS10 (p 0.001). The mRNA expression levels of TLR4 significantly increased in the liver, heart, and kidneys (p 0.001) at HS10, and in the kidneys at HS5 (p=0.003). It is found that TLR4 mRNA expression at HS10 in different organs was significantly higher (p 0.001) compared with HS2 and HS5. The results of the present study suggest that AHS may modulate the functional responses of the liver, kidney, spleen, heart, and small intestine of broilers by regulating TLR4 mRNA expression.(AU)

Efeito de diferentes estressores na produção de leite de cabras Saanen e suas relações com estresse oxidativo na glândula mamária

A exploração da Caprinocultura vem crescendo e sendo considerada uma opção rentável, principalmente para exploração leiteira, pois o leite de cabra é considerado um alimento de alto valor nutritivo e indicado nos casos em que indivíduos possuem problemas digestivos ou intolerância ao leite de vaca. A melhoria na qualidade do leite, manutenção e aumento da produção leiteira são os principais elementos deste agronegócio. Em geral, as cabras são descritas como robustas em comparação com outras espécies de gado em condições adversas do meio ambiente e manejo. No entanto, o estresse altera sua homeostase com consequências negativas na produção de leite. Por outro lado, a maioria dos estudos relacionados ao estresse em zootecnia é realizado apenas com um estressor, e esses estudos não consideram que o estresse pode ser cumulativo e agravar as perdas produtivas. Por essas razões, o presente estudo analisou os efeitos do estresse agudo cumulativo causado por diferentes estressores na produção de leite, na qualidade do leite e sua influência na expressão de células epiteliais mamárias em 30 cabras Saanen em final de lactação. Os animais foram expostos a diferentes estressores ambientais e de manejo ou mantidos em condições de conforto (grupo controle). Os estressores foram estresse por calor, administração de hormônio adrenocorticotrófico (ACTH), cuidados com os cascos e chuva durante quatro dias consecutivos em dezembro de 2018 e fevereiro de 2019. Embora, as cabras submetidas aos diferentes estressores foram capazes de restabelecer a homeostase, a exposição aos desafios ambientais e de manejo (calor, ACTH, cuidado do casco e chuva) diminuíram a produção de leite das cabras, demonstrando um efeito cumulativo dos estressores agudos. De fato, houve efeitos significativos dos estressores na frequência respiratória, temperatura retal, cortisol, insulina, triiodotironina e nas concentrações de fator de crescimento semelhante à insulina 1 das cabras (P 0,005) em comparação com o observado no grupo controle. Houve efeito significativo do estresse sobre a glicose, ureia, triglicerídeos, colesterol, lipoproteína de alta densidade e lipoproteína de baixa densidade. Os estressores também aumentaram significativamente a expressão dos genes GR, CAT, SOD e IFN- no tecido mamário das cabras Saanen. Por essas razões, os estressores resultaram em um aumento da contagem de células somáticas (CCS) no leite e uma diminuição na produção de leite em comparação às cabras controle. Nesse contexto, os resultados deste estudo indicam que os produtores devem evitar os efeitos cumulativos dos estressores agudos, pois eles têm um impacto negativo na produção de leite.

Goat husbandry is considered a profitable option to farmers mainly for dairy, in fact goat's milk have a high nutritional value and is indicated when people have digestive problems or intolerance to cow's milk. However, the improvement of production and quality of milk are the main goal of this agribusiness. In general, goats are described to be more robust compared to other livestock species to adverse environmental conditions and management. However, the stress changes its homeostasis having negative consequences on milk production. By other way, most of studies related to stress in animal science are performed with just a stressor, and these studies not considering that stress may be cumulative and aggravate productive losses. For these reasons, the present study analyzed the effects of cumulative acute stress caused by different stressors on milk yield, milk quality and its influence on the expression of mammary epithelial cells in in 30 Saanen goats at the end of lactation. The animals were exposed to different environmental and management stressors or maintained under conditions of comfort (control group). The stressors were heat stress, adrenocorticotropic hormone (ACTH) administration, hoof care and rain during four consecutive days in December 2018 and February 2019. Although, goats subjected to different stressors were able to restore homeostasis, the exposure of goats to environmental and management challenges (heat stress, ACTH, hoof care, and rain) decreased the milk yield of Saanen goats, demonstrating a cumulative effect of the acute stressors. In fact, there were significant effects of the stressors on respiratory rate, rectal temperature, cortisol, insulin, triiodothyronine and insulin-like growth factor 1 concentrations of the goats (P 0.05) compared with that observed in control group. There was a significant stress effect on glucose, urea, triglycerides, cholesterol, highdensity lipoprotein and low-density lipoprotein. The stressors also significantly increased the expression of GR, CAT, SOD and IFN- genes in the mammary tissue of Saanen goats. For these reasons, the stressors resulted in an increase of somatic cell count (SCC) in milk and a decrease of milk yield in comparison to the control goats. In this context, the results of this study indicate that farmers should avoid the cumulative effects of acute stressors because they have a significant negative impact on milk production.

The Strategic Application of Electrolyte Balance to Minimize Heat Stress in Broilers

Several physiological and metabolic changes are triggered in broilers submitted to high environmental temperatures, resulting in performance losses. Feed formulation manipulation of the dietary electrolyte balance may be applied to reduce the negative impact of heat stress on broiler performance. This experiment was carried out to evaluate the effect of the manipulations of dietary electrolytes by combining changes in the electrolyte (Na++K+-Cl-) balance (EB) and in the [(K++Cl-)/Na+] ratio (ER) in broiler feeds. In total, 1575 male broilers between 21 and 46 days old were allotted to 15 treatments in a 5x3 factorial arrangement, consisting of five diets with different EB/ER combinations (150/3, 250/2, 250/3, 250/4, and 350/3). Birds were submitted to heat stress at 25 or 35 days old. Live performance, mortality rate, and carcass traits were evaluated. The strategic formulation of diets with different EB and ER improves live performance and minimize the effect of heat stress on broilers. Under thermoneutral conditions, an EB of 250 mEq/kg and an ER of 3 are recommended, whereas under heat stress, and EB of 350 mEq/kg and an ER of 3 should be applied.(AU)

The Strategic Application of Electrolyte Balance to Minimize Heat Stress in Broilers

Several physiological and metabolic changes are triggered in broilers submitted to high environmental temperatures, resulting in performance losses. Feed formulation manipulation of the dietary electrolyte balance may be applied to reduce the negative impact of heat stress on broiler performance. This experiment was carried out to evaluate the effect of the manipulations of dietary electrolytes by combining changes in the electrolyte (Na++K+-Cl-) balance (EB) and in the [(K++Cl-)/Na+] ratio (ER) in broiler feeds. In total, 1575 male broilers between 21 and 46 days old were allotted to 15 treatments in a 5x3 factorial arrangement, consisting of five diets with different EB/ER combinations (150/3, 250/2, 250/3, 250/4, and 350/3). Birds were submitted to heat stress at 25 or 35 days old. Live performance, mortality rate, and carcass traits were evaluated. The strategic formulation of diets with different EB and ER improves live performance and minimize the effect of heat stress on broilers. Under thermoneutral conditions, an EB of 250 mEq/kg and an ER of 3 are recommended, whereas under heat stress, and EB of 350 mEq/kg and an ER of 3 should be applied.

Effects of Heat Stress on the Daily Behavior of Wenchang Chickens

One-day old chicks were randomly distributed into acute heat stress (AHS) or persistent heat stress (PHS) groups. Each group was further divided into control (CK), and three AHS ages (1, 2,or 3 weeks of age) experimental subgroups. The chicks in AHS subgroups were submitted to acute heat stress (40oC for two hours between 12:00 and 14:00 hours during the weekend) and the effects of heat stress on several daily behaviors were observed. At 8 days of age, the chicks of PHS subgroups were submitted to heat stress (40oC daily). The heat treatment ceased during the weekends and the effects on the behavior were observed three times daily for three consecutive days. The results showed that, compared with the CK group, the duration and frequency of drinking and lying-down behaviors of the AHS birds increased, whereas the duration of feeding and standing significantly decreased (p 0.01). The time spent walking by PHS birds was significantly longer than that of the CK groups (p 0.01), and drinking was also significantly longer than that of the CK group and was significantly different when birds were three weeks old (p=0.05). When heat stress lasted for two and three weeks in PHS group, the duration of lying down was longer compared with the CK group; however, this behavior was significantly shorter than the CK group when birds were three weeks old (p 0.05). These results indicate that heat stress significantly affects the daily behavior of broilers, including feeding, drinking, lying, standing, and walking.

Effects of Heat Stress on the Daily Behavior of Wenchang Chickens

One-day old chicks were randomly distributed into acute heat stress (AHS) or persistent heat stress (PHS) groups. Each group was further divided into control (CK), and three AHS ages (1, 2,or 3 weeks of age) experimental subgroups. The chicks in AHS subgroups were submitted to acute heat stress (40oC for two hours between 12:00 and 14:00 hours during the weekend) and the effects of heat stress on several daily behaviors were observed. At 8 days of age, the chicks of PHS subgroups were submitted to heat stress (40oC daily). The heat treatment ceased during the weekends and the effects on the behavior were observed three times daily for three consecutive days. The results showed that, compared with the CK group, the duration and frequency of drinking and lying-down behaviors of the AHS birds increased, whereas the duration of feeding and standing significantly decreased (p 0.01). The time spent walking by PHS birds was significantly longer than that of the CK groups (p 0.01), and drinking was also significantly longer than that of the CK group and was significantly different when birds were three weeks old (p=0.05). When heat stress lasted for two and three weeks in PHS group, the duration of lying down was longer compared with the CK group; however, this behavior was significantly shorter than the CK group when birds were three weeks old (p 0.05). These results indicate that heat stress significantly affects the daily behavior of broilers, including feeding, drinking, lying, standing, and walking.(AU)

ESTRESSE, IMUNIDADE, SISTEMA ANTIOXIDANTE E METABOLISMO EM PEIXES EM CONDIÇÕES SIMULADAS COMUNS DA CRIAÇÃO

Muitas situações inerentes da piscicultura intensiva desencadeiam resposta de estresse nos animais, podendo causar perdas na produtividade. Manejos como a perseguição e o transporte e alterações na qualidade de água como baixos níveis de oxigênio dissolvido (OD) e mudanças na temperatura são exemplos de condições estressantes para os peixes. O conhecimento do impacto dessas condições na fisiologia dos peixes é importante para antever respostas e melhorar a saúde e bem-estar dos peixes, evitando, em consequência, perdas na produção. O uso de imunoestimulantes, como o -glucano, na aquicultura, é uma alternativa para minimizar os efeitos negativos do estresse, incluindo prejuízos no sistema imune. Além disso, tanto as respostas metabólicas do estresse quanto as respostas do sistema imune são energeticamente caras e podem ter efeito no sistema de produção de energia e balanço redox intracelular. Neste contexto, esta tese é composta por três experimentos que objetivaram avaliar o efeito de situações estressantes na resposta de estresse, metabólica, imune e antioxidante de peixes imunoestimulados ou não com -glucano. No primeiro experimento, juvenis de pacu, alimentados com -glucano, foram submetidos à estresse crônico (perseguição) ou/e agudo (transporte), e inoculação com Aeromonas hydrophila inativada pelo calor. No segundo experimento, que originou dois capítulos desta tese, salmões foram mantidos por seis semanas em hipóxia (40% OD) e posteriormente foram inoculados com Aeromonas salmonicida inativada com formalina. No terceiro experimento, pacus foram alimentados com -glucano e passaram por um desafio térmico, com queda severa na temperatura da água antes da inoculação com lipopolissacarídeo (LPS). Todos os estressores utilizados neste estudo desencadearam uma resposta de estresse nos peixes, prejudicando a resposta imune, antioxidante e metabólica. Enquanto os estressores agudos (transporte e estresse térmico) provocaram aumento na concentração plasmática de cortisol e/ou glicose, os estressores crônicos (perseguição e hipóxia) fadigaram a responsividade do eixo HPI. A imunoestimulação, seja por LPS ou por bactéria potencializou os efeitos negativos dos estressores, especialmente na resposta antioxidante. O -glucano apresentou efeito protetor, diminuindo picos na concentração plasmática de cortisol e evitando a redução na atividade do sistema antioxidante.

Many inherent situations in intensive fish farming trigger stress response on animals, which can cause productivity losses. Chase, transport and changes in water quality, as low dissolved oxygen (DO) levels and alterations in water temperature are examples of stressful conditions for fish. Understanding the impact of stressful situations on fish physiology is important to predict responses and improving fish health and well-being, preventing production losses. The use of immunostimulants, as -glucan, in aquaculture, is an alternative to minimize the negative impacts of stress, including those in immune system. In addition, both metabolic and immune system responses are of high energy cost, and can affect the cellular system of energy production and the intracellular redox balance. In this context, this thesis is composed of three experiments that aimed to evaluate the effects of stressful situations on the stress, immune, metabolic and antioxidant response of non-immunestimulated or glucan-immunestimulated fish. In the first experiment, pacu juveniles fed with -glucan were subjected to chronic (chase) or/and acute (transport) stress and heat-killed Aeromonas hydrophila. In the second experiment, present in two chapters of this thesis, salmon were kept in hypoxia (40% DO) for six weeks before injection with formalin-killed Aeromonas salmonicida. In the third experiment, pacu fed with -glucan were thermal challenged, with severe reduction in water temperature prior lipopolysaccharide (LPS) inoculation. All stressors applied in this study triggered a stress response in fish, impairing the immune, antioxidant and metabolic responses. While acute stressors (transport and thermal challenge) increased plasma cortisol and/or glucose concentration, chronic stressors (chase and hypoxia) reduced the responsiveness of HPI axis. Immunostimulation, either by LPS or bacteria, potentiated the negative effects of stressors, especially in the antioxidant response. The glucan showed a protective effect, reducing peaks in plasma cortisol concentrations and avoiding a decrease in antioxidant system activity.

EXPRESSÃO DIFERENCIAL DE GENES RELACIONADOS À TERMOTOLERÂNCIA EM FRANGOS SUBMETIDOS AO ESTRESSE POR CALOR

No Brasil, a avicultura tem grande impacto econômico e o país se destaca como o maior exportador e o segundo maior produtor de carne de frango. Essa potencialização do agronegócio ocorreu devido à intensa seleção genética dessas aves, que aperfeiçoaram suas características produtivas. Entretanto, a capacidade de adaptação dessas aves diminuiu. Em contrapartida, as raças naturalizadas como a Peloco e a Caneluda, são rústicas e estão mais adaptadas aos diversos ambientes e, por ser criadas no sistema de avicultura familiar que não exigem sistemas de criação sofisticados representam uma boa alternativa para a região Nordeste por. Muitos dessas aves encontram-se ameaçadas de extinção, necessitando de pesquisas que identifiquem seu potencial zootécnico e garanta sua conservação. Genes de resposta ao estresse por calor e ao estresse foram identificados em diversos organismos, um exemplo são as Proteínas de Choque Térmico (HSPs), que desempenham papéis cruciais na proteção de células em condição de estresse. Esses genes podem ser expressos em diferentes fases e tecidos do animal. A PCR quantitativa em tempo real (RTqPCR) é uma das principais técnicas para verificar a expressão dos genes ligados ao estresse. Diante disso, o objetivou-se com esse trabalho estabelecer um gene de referência, à partir de oito primers selecionados na literatura e, avaliar e comparar os níveis de expressão de genes relacionados ao estresse térmico (HSF1, HSF3, HSP70, HSP90) e genes codificadores de enzimas antioxidantes (CASP, CAT, SOD e GPx) em fragmentos do rim dos ecótipos Peloco e Caneluda e da linhagem comercial Coob500 em situação de conforto e estresse por calor agudo. O gene MRPS30 foi considerado o mais estável no rim para os fatores avaliados e, por isso, foi utilizado como o normalizador dos genes alvos. Em relação à expressão relativa dos genes alvos pôde-se observar que o ecótipo Peloco apresentou diferenças significativas de expressão quando comparado aos outros grupos genéticos. Assim, nos genes HSF1 e HSF3, o ecótipo Peloco teve sua expressão aumentada e nos genes HSP70 e HSP90, sua expressão diminuiu. No gene HSP90, o ecótipo Caneluda mostrou ter expressão significativamente diferente dos outros grupos, e Peloco apresentouix diferenças de expressão em relação ao fator ambiente. Já análises referentes dos genes relacionados ao estresse oxidativo mostraram uma expressão relativa bem parecida, não evidenciando diferenças estatísticas entre os fatores estudados. A exceção foi o gene CATALASE que demonstrou diferença de expressão desse gene quando comparamos Peloco e os outros grupos genéticos no ambiente conforto. Os genes relacionados ao estresse do retículo endoplasmático (GRP78; EI2F; IRE1 e ATF6) apresentaram divergências nos níveis de expressão nos diferentes tecidos de dois grupos de frangos. O gene GRP78 no Coração da Cobb 500® evidenciou um aumento no nível de expressão após o estresse térmico. Por outro lado, no fígado e no rim, notamos que grupo peloco expressou níveis maiores do que Cobb 500® no em ambiente conforto. Além disso, dentro da linhagem comercial níveis significativamente maiores foram detectados após o estresse térmico no rim. Em relação ao gene EI2F, os tecidos coração e músculo do mRNA não expressaram diferenças significaticvas após os tratamentos. No fígado a linhagem Cobb 500® expressou níveis maiores do que o grupo Peloco após estresse térmico e, no rim, contrariamente o ecótipo Peloco que aumentou consideravelmente após estresse térmico. A expressão do mRNA do IRE1 apresentou diferenças significativas apenas no rim, no qual o grupo Peloco expressou níveis maiores que Cobb 500® após o estresse térmico. Além disso, podemos afirmar que o estresse térmico ativou a via do IRE1 para o ecótipo Peloco em relação aos animais em conforto térmico. No fígado, a expressão do ATF6, foi maior na linhagem comercial em relação ao ecótipo Peloco após o estresse térmico. Inversamente, no rim do grupo Peloco houve maior expressão em relação linhagem comercial. Já no coração, o estresse térmico reduziu significativamente a expressão desse gene no ecótipo Peloco. Em relação à Caspase6, não observamos divergências entre as raças, nem entre os tratamentos. Os resultados aqui mostraram o ecótipo Peloco está mais adaptada as altas temperaturas do que o ecótipo caneluda, bem como a linhagem comercial.

In Brazil, poultry has a great economic impact and the country stands out as the largest exporter and the second largest producer of chicken meat. This potentiation of agribusiness occurred due to the intense genetic selection of these birds, which improved their productive characteristics. However, the adaptability of these birds has decreased. In contrast, naturalized breeds such as Peloco and Caneluda, are rustic and are more adapted to different environments and, being raised in the family poultry system that do not require sophisticated breeding systems, represent a good alternative for the Northeast region. Many of these birds are threatened with extinction, requiring research that identifies their zootechnical potential and ensures their conservation. Genes of response to heat stress and stress have been identified in several organisms, one example being Thermal Shock Proteins (HSPs), which play crucial roles in protecting cells in stress conditions. These genes can be expressed in different phases and tissues of the animal. Real-time quantitative PCR (RTqPCR) is one of the main techniques for verifying the expression of stress-linked genes. Therefore, the objective of this work was to establish a reference gene, from eight primers selected in the literature, and to evaluate and compare the levels of expression of genes related to thermal stress (HSF1, HSF3, HSP70, HSP90) and genes coders of antioxidant enzymes (CASP, CAT, SOD and GPx) in fragments of the kidney of the Peloco and Caneluda ecotypes and of the commercial strain Coob500 in a situation of comfort and stress due to acute heat. The MRPS30 gene was considered the most stable in the kidney for the factors evaluated and, therefore, it was used as the normalizer of the target genes. Regarding the relative expression of the target genes, it was observed that the Peloco ecotype showed significant differences in expression when compared to other genetic groups. Thus, in the HSF1 and HSF3 genes, the Peloco ecotype had its expression increased and in the HSP70 and HSP90 genes, its expression decreased. In the HSP90 gene, the Caneluda ecotype showed expression significantly different from the other groups, and Peloco showed differences in expression in relation to the environment factor. Relative analyzes of genes related to oxidative stress showed a very similarxi relative expression, not showing statistical differences between the factors studied. The exception was the CATALASE gene, which showed a difference in expression of this gene when we compared Peloco and the other genetic groups in the comfort environment.The stress-related genes of the endoplasmic reticulum (GRP78; EI2F; IRE1 and ATF6) showed differences in the levels of expression in the different tissues of two groups of chickens. The GRP78 gene in the Cobb 500® Heart showed an increase in the level of expression after thermal stress. On the other hand, in the liver and kidney, we noticed that the peloco group expressed higher levels than Cobb 500® in the comfort environment. In addition, within the commercial strain, significantly higher levels were detected after heat stress in the kidney. Regarding the EI2F gene, the heart and muscle tissues of the mRNA did not express significant differences after the treatments. In the liver, the Cobb 500® strain expressed higher levels than the Peloco group after thermal stress and, in the kidney, unlike the Peloco ecotype, which increased considerably after thermal stress. The expression of the IRE1 mRNA showed significant differences only in the kidney, in which the Peloco group expressed levels greater than Cobb 500® after thermal stress. In addition, we can say that thermal stress activated the IRE1 pathway for the Peloco ecotype in relation to animals in thermal comfort. In the liver, the expression of ATF6 was greater in the commercial strain compared to the Peloco ecotype after thermal stress. Conversely, in the kidney of the Peloco group, there was greater expression in relation to commercial lineage. In the heart, thermal stress significantly reduced the expression of this gene in the Peloco ecotype.Regarding Caspase6, we did not observe any divergences between races or treatments. The results here showed the Peloco ecotype is more adapted to high temperatures than the fluted ecotype, as well as the commercial strain.

EFEITO DE Lactobacillus spp. EM FRANGOS DE CORTE EXPOSTOS AO DESOXINIVALENOL

A avicultura contribui com importante parcela do produto interno bruto brasileiro, devido a 10 sua crescente eficiência, em que se destacam os avanços em genética, nutrição e sanidade. A 11 saúde animal pode ser afetada pela ingestão aguda ou crônica de micotoxinas, metabólitos 12 produzidos por fungos, que contaminam 80% dos grãos mundialmente. Estratégias para 13 mitigar os danos induzidos por estes compostos, como a biotransformação, podem contribuir 14 com a produção e sanidade avícola. O objetivo deste estudo foi avaliar o efeito da utilização 15 de um pool de Lactobacillus spp. em diferentes apresentações sobre a saúde de frangos de 16 corte alimentados com uma dieta contaminada por desoxinivalenol (DON) a uma concentração de 19,3 mg kg-1 17 . Para tanto frangos de corte (n 50) com um dia de vida (dv) foram divididos em cinco tratamentos: controle, DON (19,3 mg kg-1 18 ), Lactobacillus spp. 19 viável + DON (LV+DON), Lactobacillus spp. inativado pelo calor + DON (LI+DON) e 20 Lactobacillus spp. sobrenadante de cultura + DON (LS+DON). A ingestão da dieta 21 contaminada iniciou-se aos 7 dv. O pool de Lactobacillus spp. foi fornecido via gavagem a 22 partir do segundo dv. Aos 14 dv, os animais foram eutanasiados e fragmentos de duodeno, 23 jejuno, íleo, ceco, fígado e rins foram colhidos para avaliação histomorfométrica. A resposta 24 ao estresse oxidativo foi avaliada por meio dos testes Thiobarbituric Acid Reactive 25 Substances (TBARS) e Nitro Blue Tetrazolium (NBT); e a resposta antioxidante por meio dos 26 testes reducing of 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric 27 reducing ability (FRAP) e reduced glutathione (GSH). A ingestão de DON induziu lesões 28 intestinais e hepáticas significativas em comparação com os demais tratamentos, enquanto 29 que os tratamentos com Lactobacillus spp. (TL) permaneceram semelhantes ao controle. 30 Redução na altura de vilosidades e aumento na profundidade de criptas intestinais foram 31 observadas no grupo DON em comparação ao controle. Todos os TL apresentaram 32 profundidade de cripta similar ao controle, e uma maior relação vilo:cripta no duodeno e 33 jejuno. No íleo apenas LV+DON melhorou a relação vilo:cripta. A ingestão de dieta com 34 DON aumentou a contagem de células caliciformes no íleo, todos TL apresentaram uma 35 menor contagem em relação ao grupo DON. Exposição ao DON aumentou a contagem de 36 linfócitos intraepiteliais no jejuno e íleo, entretanto LV+DON apresentou uma redução 37 comparado aos demais tratamentos em ambos segmentos intestinais. DON elevou os níveis de 38 TBARS no jejuno, porém os tratamentos LV+DON e LI+DON permaneceram similar ao 39 grupo controle. Uma redução nos níveis de GSH e ABTS foi observada no jejuno. No fígado, 40 DON aumentou os níveis de NBT e reduziu os níveis de FRAP, os TL permaneceram 41 similares ao grupo controle. No rim, TBARS e NBT não foram alterados por DON. Em geral, 42 a capacidade de resposta ao estresse oxidativo no rim se manteve semelhante entre os 43 tratamentos. O pool de Lactobacillus spp. utilizado foi capaz de melhorar a saúde intestinal 44 após a exposição ao DON e reduzir o dano induzido pelo estresse oxidativo, principalmente 45 no jejuno e fígado.

The aviculture contributes to an important portion of Brazils gross domestic product due to 10 its increasing efficiency, which highlights advances in genetics, nutrition, and sanity. The 11 animal health can be affected by acute or chronic mycotoxins ingestion, which are metabolites 12 produced by fungi, that contaminates 80% of the grains worldwide. Strategies to mitigate the 13 damage induced by these compounds, such as biotransformation, can contribute to poultry 14 production and health. The aim of this study was to evaluate the effects of the utilization of a 15 Lactobacillus spp. pool in different presentations on the health of broilers fed a diet contaminated by deoxynivalenol (DON) at a concentration of 19.3 mg kg-1 16 . For this purpose 17 broilers (n 50) with one day of age (da) were divided into five treatments: control; DON (19,3 mg kg-1 18 ); viable Lactobacillus spp. + DON (VL+DON); heat-inactivated Lactobacillus spp. + 19 DON (HIL+DON) and Lactobacillus spp. culture supernatant + DON (LCS+DON). The 20 intake of the contaminated diet began at 7 da. The pool of Lactobacillus spp. was provided via 21 oral gavage starting at the second da. At 14 da, the animals were euthanized and fragments of 22 duodenum, jejunum, ileum, caecum, liver, and kidneys were collected for the 23 histomorphometrical evaluation. The oxidative stress response was evaluated by the tests 24 Thiobarbituric Acid Reactive Substances (TBARS) and Nitro Blue Tetrazolium (NBT); and 25 the antioxidant response by the tests reducing of 2,2'-azino-bis 3-ethylbenzothiazoline-6- 26 sulphonic acid (ABTS), ferric reducing ability (FRAP) and reduced glutathione (GSH). The 27 ingestion of DON induced significativilly intestinal and liver lesions compared with the other 28 treatments, while the Lactobacillus spp. treatments (LT) kept similar to control. Reduction of 29 the villi height and an increase in the intestinal crypt depth were observed in the DON group 30 compared to control. All LT presented similar crypt depth to the control and a higher 31 villi:crypt ratio in the duodenum and jejunum. In the ileum, only VL+DON improved the 32 villi:crypt ratio. Ingestion of DON-contaminated diet induced an increase in goblet cells in the 33 ileum, all LT presented a lower count in relation to the DON group. DON exposure increased 34 intraepithelial lymphocyte count in the jejunum and ileum, however, VL+DON decreased 35 compared to other treatments in both intestinal segments. DON raised the levels of TBARS in 36 the jejunum, but the treatments LV+DON and HIL+DON remained similar to the control 37 group. A reduction in GSH and ABTS levels was observed in the jejunum. In liver, DON 38 increased NBT levels and reduced the FRAP levels the LT kept similar to the control group. 39 In the kidney, TBARS and NBT were not altered by DON. In general, the oxidative stress 40 response in the kidney remained similar among the treatments. The pool of Lactobacillus spp. 41 used was able to improve intestinal health after DON exposure and reduce the damage 42 induced by oxidative stress, especially in the jejunum and liver.

Protocolos para indução de artrite em leitões na fase de aleitamento e avaliação do óleo essencial de laranja microencapsulado após o desmame

Artrites são inflamações articulares que geram atraso no desenvolvimento de leitões, perda de peso, resposta inflamatória e estresse oxidativo. Considerando a necessidade de padronização de um método para indução de artrite em leitões, para uso em pesquisas que busquem mitigar seus efeitos, o presente estudo foi realizado com objetivo de determinar uma metodologia de indução de artrite na fase de lactação e posterior utilização dietética de óleo de laranja microencapsulado em substituição total ou parcial a antibiótico, por ser um produto com alto teor de polifenóis e flavonoides, com potencial de mitigar os efeitos secundários da inflamação articular, devido às suas propriedades antimicrobianas e antioxidantes. Experimento I: Foram utilizadas 48 fêmeas suínas mestiças (Topigs x AGPIC 425), com idade inicial de 7 dias e peso médio inicial de 1,76 ± 0,28 kg. Metade desses animais (n=24) foi submetida à indução de artrite, na articulação tarso-falange do membro posterior direito, através de injeção intradérmica de adjuvante completo de FREUND (Mycobacterium tuberculosis derivadas de cepa humana H37Rv e inativadas pelo calor, suspendidas em óleo mineral 0,5% (w/v)). Foram testados os protocolos de aplicação I (7 dias de idade - 0,1 mL de adjuvante), II (7 e 14 dias de idade - 0,2 mL de adjuvante), III (14 e 21 dias de idade - 0,2 mL de adjuvante) e IV (7, 14 e 21 dias de idade - 0,3 mL de adjuvante). A outra metade dos animais (n=24) foi submetida ao mesmo manejo, porém com aplicações de soro fisiológico (0,9%). Todos os animais foram desmamados aos 21 dias de idade e alojados individualmente em baias de creche por 15 dias, para as avaliações pós-desmame. O delineamento experimental foi em blocos casualizados, com quatro protocolos de indução do grupo positivo (adjuvante) e quatro do controle (soro fisiológico), com 6 repetições por tratamento e um animal por unidade experimental. As avaliações de peso vivo, temperatura superficial e morfologia articular foram realizadas no dia do desmame (dia 0), aos 3, 6, 9, 12 e 15 dias pós desmame. No último dia, foram realizadas as coletas de sangue para determinação plasmática de GSH, TAC, tióis e proteínas carboniladas, e dosagem sérica das proteínas de fase aguda, além de coleta de fígado para determinação da catalase, SOD e proteínas carboniladas, e de líquido sinovial para a contagem de leucócitos. Todos os protocolos de indução resultam na manifestação da doença na fase pós-desmame. A aplicação de adjuvante aos 7 dias é o protocolo indicado, devido à viabilidade técnica, pois os animais são mais leves, de fácil contenção e utiliza-se apenas uma dose de adjuvante. Experimento II: Foram utilizadas 64 fêmeas suínas com peso médio inicial de 5,67 ± 0,18 kg, desmamadas aos 21 dias. Os animais foram distribuídos em delineamento experimental de blocos ao acaso, em esquema fatorial 2 X 4, cujos tratamentos consistiram na indução de artrite por adjuvante ou não e 4 rações experimentais. Foram utilizadas 8 repetições por tratamento e um animal por unidade experimental. Os tratamentos avaliados foram: controle negativo (ração sem adição de antibiótico ou limoneno), controle positivo (ração com antibiótico: 300 ppm de lincomicina 44%), limoneno (ração com limoneno: 500 ppm de D-limoneno 12,38%) e limoneno + antibiótico (ração com limoneno: 250 ppm de D-limoneno 12,38% + antibiótico: 150 ppm de lincomicina 44%). Foram mensuradas variáveis de desempenho, parâmetros morfológicos, bioquímicos, hematológicos e de estado oxidativo no sangue dos leitões recém-desmamados. A indução de artrite por adjuvante na lactação resulta em queda de peso vivo ao desmame, piora no desempenho, estresse inflamatório e oxidativo, elevação de temperatura superficial e das variáveis morfológicas da articulação. O uso de Limoneno microencapsulado (500 ppm de D-limoneno 12,38%) ou de Limoneno microencapsulado + Antibiótico (250 ppm de D-limoneno 12,38% + 150 ppm de lincomicina 44%) mitigam os efeitos do estresse oxidativo em animais na fase pós-desmame gerados pela artrite induzida na fase de lactação.

Arthritis is joint inflammation that causes piglet development delay, weight loss, inflammatory response and oxidative stress. Need for standardization of a method to induce arthritis in piglets, for use in research that seeks to mitigate its effects, the present study was carried out with the objective of determining an arthritis induction methodology in the lactation phase and subsequent dietary use of orange oil microencapsulated to replace antibiotics, as it is a product with a high content of polyphenols and flavonoids, with the potential to mitigate the effects of joint inflammation, due to its antimicrobial and antioxidant properties. Experiment I: 48 crossbred gilts (Topigs x AGPIC 425) were used, with an initial age of 7 days and an average initial weight of 1.76 ± 0.28 kg. Half of these animals (n = 24) were submitted to arthritis induction, in the tarsophalange joint of the right posterior limb, through intradermal injection of complete FREUND adjuvant (Mycobacterium tuberculosis derived from human H37Rv strain and inactivated by heat, suspended in oil mineral 0.5% (w / v)). Application protocols I (7 days old - 0.1 ml of adjuvant), II (7 and 14 days of age - 0.2 ml of adjuvant), III (14 and 21 days of age - 0.2 mL of adjuvant) and IV (7, 14 and 21 days of age - 0.3 mL of adjuvant). The other half of the animals (n = 24) were submitted to the same management, but with saline applications (0.9%). All animals were weaned at 21 days of age and housed individually in a swine nursery for 15 days, for post-weaning assessments. The experimental design was in randomized blocks, with four protocols for induction of the positive group (adjuvant) and four of the control (saline), with 6 replicates per treatment and one animal per experimental unit. Assessments of live weight, surface temperature and joint morphology were performed on the day of weaning (day 0), at 3, 6, 9, 12 and 15 days after weaning. On the last day, blood samples were taken for plasma determination of GSH, TAC, thiols and carbonylated proteins, and serum measurement of acute phase proteins, in addition to liver collection for the determination of catalase, SOD and carbonylated proteins and synovial fluid for leukocyte count. All arthritis induction protocols for piglets in the lactation phase result in the manifestation of the disease in the post-weaning phase. The application of adjuvant at 7 days is the indicated protocol, due to the technical feasibility, as the animals are lighter, easy to contain and only one dose of adjuvant is used. Experiment II: 64 gilts with an average initial weight of 5.67 ± 0.18 kg were used, weaned at 21 days. The animals were distributed in a randomized block design, in a 2 X 4 factorial scheme, whose treatments consisted of inducing arthritis by adjuvant or not and 4 experimental diets. Eight replicates per treatment and one animal per experimental unit were used. The evaluated treatments were: negative control (ration without addition of antibiotic or limonene), positive control (ration with antibiotic: 300 ppm of lincomycin 44%), limonene (ration with limonene: 500 ppm of D-limonene 12.38%) and limonene + antibiotic (diet with limonene: 250 ppm of D-limonene 12.38% + antibiotic: 150 ppm of lincomycin 44%). Performance variables, morphological, biochemical, hematological parameters and oxidative status were measured in the blood of newly weaned piglets. The induction of arthritis by adjuvant in lactation results in a drop in live weight at weaning, worsening in performance, inflammatory and oxidative stress, elevation of surface temperature and joint morphological variables. The use of microencapsulated Limonene (500 ppm D-limonene 12.38%) or microencapsulated Limonene + Antibiotic (250 ppm D-limonene 12.38% + 150 ppm lincomycin 44%) mitigate the effects of oxidative stress in animals in the postweaning phase generated by arthritis induced in the lactation phase.

PERFIL GÊNICO DE MEDIADORES DE ESTRESSE TÉRMICO E OXIDATIVO DO ECOTIPO PELOCO E FRANGO DE LINHAGEM COMERCIAL

A agricultura familiar possui grande importância para o desenvolvimento regional, sendo a base de subsistência de muitas famílias. Em algumas regiões no interior da Bahia, existe um ecotipo de frango que foi introduzida no Brasil, denominada Peloco, que se caracteriza pela resistência à alta temperatura, adaptabilidade e rusticidade. Esta ave encontra-se em número reduzido, havendo a necessidade de pesquisas para a conservação dessas características e de seu material genético. Existem genes que estão relacionados à resistência ao estresse por calor e genes relacionados ao estresse oxidativo que podem ser expressos em diferentes fases do desenvolvimento e tecidos do animal. A técnica de RT-qPCR verifica a expressão dos genes ligados ao estresse térmico e oxidativo, porém é necessário realizar a padronização e escolha de um gene de referência para normalização dos genes alvos. Tendo isso em vista, objetivou-se com esse trabalho identificar genes de referência estáveis para a normalização de genes alvos no tecido coração e fígado de ecotipos Peloco e frangos de linhagem comercial Cobb 500®, submetidos ao conforto térmico e estresse térmico agudo, bem como, avaliar e comparar os efeitos do calor elevado sobre os níveis de expressão de genes relacionados ao estresse térmico e oxidativo nesses tecidos nos dois grupos genéticos de frangos. Vinte e quatro aves (12 Peloco e 12 Cobb 500®) foram submetidas ao ambiente de conforto térmico (23°C) e de estresse térmico agudo (39,5°C, por 1 hora), posteriormente, foram abatidos e coletados fragmentos de fígado e coração para estudo de expressão gênica. Três algoritmos estatísticos foram utilizados para avaliar a estabilidade da expressão dos genes de referência no grupo de amostras (BestKeeper, GeNorm e NormFinder). Após as análises, o gene considerado mais estável foi o RPL5 em ambos tecidos estudados. Nas análises de expressão relativa, os genes HSP70 e HSF1 tiveram aumento de expressão estatisticamente significativo no tecido fígado dos frangos submetidos ao estresse térmico agudo. O HSP90 apresentou aumento de expressão estatisticamente significativo nos dois tecidos dos animais submetidos ao estresse por calor (p<0,05). O gene CAT revelou aumento de expressão significativo no fígado dos animais Cobb 500® submetidos à alta temperatura, já o SOD foi mais expresso apenas no tecido coração da Peloco e o GPX apresentou aumento de expressão significativa nos dois ii tecidos nos animais Peloco submetidos ao estresse térmico agudo. Diante disso, foi possível concluir que existe variação de expressão dos genes entre os frangos submetidos ao estresse térmico agudo, e que os genes relacionados ao estresse térmico e oxidativo revelaram aumento de expressão no ecotipo Peloco, conferindo maior resistência ao calor elevado.

Family farming has great importance for regional development, being the base of subsistence for many families. In some regions in the interior of Bahia, there is an ecotype of chicken that was introduced in Brazil, called Peloco, which is characterized by high temperature resistance, adaptability and rusticity. This bird is in small numbers, and there is a need for research for the conservation of these characteristics and their genetic material. There are genes that are related to resistance to heat stress and genes related to oxidative stress that can be expressed at different stages of development and tissues of the animal. The RT-qPCR technique verifies the expression of genes linked to thermal and oxidative stress, but it is necessary to standardize and select a reference gene for normalization of target genes. The objective of this work was to identify stable reference genes for the normalization of target genes in the heart and liver tissue of Peloco ecotypes and commercial Cobb 500® broilers subjected to thermal comfort and acute thermal stress, as well as , to evaluate and compare the effects of high heat on the expression levels of genes related to thermal and oxidative stress in these tissues in the two genetic groups of chickens. Twenty-four birds (12 Peloco and 12 Cobb 500®) were submitted to the thermal comfort environment (23 ° C) and acute thermal stress (39.5 ° C, for 1 hour), subsequently fragments of liver and heart to study gene expression. Three statistical algorithms were used to evaluate the expression stability of the reference genes in the sample group (BestKeeper, GeNorm and NormFinder). After the analysis, the gene considered more stable was RPL5 in both tissues studied. In the relative expression analyzes, the HSP70 and HSF1 genes had statistically significant expression increase in the liver tissue of chickens submitted to acute thermal stress. HSP90 presented a statistically significant increase in expression in the two tissues of the animals submitted to heat stress (p <0.05). The CAT gene revealed significant increase in liver expression of Cobb 500® animals subjected to high temperature, since SOD was more expressed only in the heart tissue of Peloco and GPX showed significant increase of expression in the two tissues in Peloco animals submitted to thermal stress acute. Therefore, it was possible to conclude that there is variation of gene expression among chickens iv submitted to acute thermal stress, and that the genes related to thermal and oxidative stress revealed an increase in expression in the Peloco ecotype, conferring greater resistance to high heat.