Background: Recent research has demonstrated the presence of heat being an effective stimulus for increasing skeletal muscle and strength. The exposure of increased environmental temperature combined with resistance training has been shown to amplify muscle adaptation for hypertrophy and strength. However, research into the potential effects of using heat stress combined with resistance training to increase performance criteria, such as speed and agility, are minimal. Utilizing a hot environment coupled with an intense exercise regime has been considered as a potential aid for sport preparation given the evidence that heat stress has on promoting hypertrophy and strength. The desired result is to enhance athletic performance. Aim: The aim of this study was to examine if (a) performing resistance training in a hot environment for 10 weeks induces greater increases in muscle mass and (b) whether this combination improves performance in speed, agility and strength compared to resistance training in a standard temperate environment. Methods: 17 healthy male adults, who have undergone a consistent regime of resistance training in the six months leading up to the study, were distributed at random into two groups; (1) Intervention group (Heat n=8) training in 40°C and (2) control group (Con, n=9) training in 23°C. Each group would follow a 10-week resistance exercise protocol. To monitor time-course adaptations, lean body mass, speed, agility and strength were measured at baseline, week 5 and week 10. Results: Over the selected training period, there was no statistically significant difference observed between the two groups or time x group interaction, over the 10-week exercise duration with respect to lean body mass, speed, agility or strength. Conclusion: Compared to the resistance training regime in the standard temperature condition of 23°C (group two), training results suggest heat stress in the hot environment at 40°C (group one) had no effective stimulus in amplifying hypertrophic adaptations in skeletal muscle nor in increasing performance in speed, agility or strength. Certain hypothetical factors were implicated for heat stress being ineffective such as potential counter-productive aspects from heat exposure or flawed methodology. / Heat Effects on Adaptations to Resistance Training, Victoria University

A aquisição de sinais cerebrais de bovinos adultos, utilizando um equipamento de transmissão telemétrica dos dados e eletrodos de superfície, foi avaliada neste trabalho através de técnicas de processamento digital de sinais. Foram estudados a melhor disposição dos eletrodos, diferentes métodos de remoção de artefatos e as características em freqüência do sinal. A remoção de artefatos foi feita de duas maneiras: (1) uso de um filtro que substituía valores extremos do sinal por seu valor médio e (2) decomposição utilizando a capacidade de multiresolução das ondaletas. Os resultados obtidos mostraram que apenas trechos de sinal livres de artefatos podem ser processados. O processamento indicou faixas de freqüências em acordo com a literatura. A metodologia usada neste trabalho mostrou-se suficiente para concluir que é possível monitorar e analisar sinais cerebrais de bovinos adultos que podem se mover livremente, sem acrescentar ao experimento o estresse característico de contenção / Acquisition of brain electrical activity from grown bovines, using a telemetric data transmitter system and scalp electrodes, was evaluated in this work. Electrodes placement, different artifact removal methodologies and signal frequency component were studied. Artifacts removal was carried out in two different ways: (1) by means of a filter that replaced elevated amplitude points for the signal’s mean value and (2) decomposition using wavelet multiresolution capability. Results using filters show that only artifact-free signal stretches can be processed. The processing indicated that frequency ranges are in agreement with literature. The methodology applied in this work is enough to conclude that it is possible to analyze brain electrical signal from grown bovines that can move freely, without add restrain stress factors to experiment

O estresse de calor prejudica o crescimento e reprodução dos organismos vegetais, ao alterar a permeabilidade de membranas biológicas e desnaturar proteínas, limitando o metabolismo primário. Dentre as respostas ao estresse abiótico, está a síntese de metabólitos secundários. Braquicerina é um alcaloide monoterpeno indólico com ação antioxidante, protetora contra UV e antimutagênica sintetizado por partes aéreas de Psychotria brachyceras. O objetivo deste trabalho é investigar o metabolismo de braquicerina sob estresse de calor. Assim, espera-se contribuir para o conhecimento acerca do metabolismo secundário nas respostas ao estresse de calor, descrever a função in planta do composto, e fornecer ferramentas para obtenção do alcaloide para fins farmacêuticos. O acúmulo de braquicerina foi induzido em discos foliares mantidos a 40ºC por três dias, tanto em regime de elevação abrupta como gradual da temperatura. Baixa temperatura (10ºC) não afetou o acúmulo do alcaloide. Discos foliares de Psychotria carthagenensis, uma espécie que não sintetiza alcaloides monoterpeno indólicos, foram também desafiados por estresse de calor. Clorofila total, teor de peróxido de hidrogênio e peroxidação lipídica foram quantificados em ambas as espécies. P. carthagenensis foi relativamente tolerante ao calor, o que pode estar relacionado à sua elevada concentração de antocianinas, fortemente induzidas por choque térmico de 50ºC por 6h. Peroxidação lipídica foi reduzida nas amostras de P. brachyceras sob estresse de calor agudo ou gradual em comparação à condição controle, sendo este parâmetro inalterado nas duas condições em P. carthagenensis. O teor de peróxido de hidrogênio foi menor em P. brachyceras submetida a choque de térmico em relação ao controle, enquanto o mesmo parâmetro não foi alterado em P. carthagenensis. Discos foliares das espécies sensíveis ao calor Brugmansia suaveolens e Brassica oleracea, pré-tratadas com braquicerina em concentrações similares às encontradas em P. brachyceras, adquiriram fenótipo tolerante ao choque térmico. A expressão do gene que codifica a enzima triptofano descarboxilase (TDC), envolvida na biossíntese de braquicerina em P. brachyceras, foi fortemente inibida em discos foliares submetidos à 40ºC por 6h, 12h e 24h, sugerindo que o efeito da temperatura na estimulação de acúmulo de alcaloide ocorra em nível pós-transcricional. Em conjunto, os dados indicam que a exposição ao calor é um meio efetivo de aumentar o rendimento de braquicerina, cuja acumulação contribui para proteção contra os danos oxidativos associados. / Heat stress impairs plant growth and reproduction by altering membrane permeability and promoting protein denaturation, which limits primary metabolism. Secondary metabolites often take part in protection against abiotic stress responses. Brachycerine is a monoterpene indole alkaloid with antioxidant, UV protectant, and antimutagenic activity synthesized by Psychotria brachyceras shoots. Brachycerine metabolism was analyzed under heat stress, in order to shed light on brachycerine‘s in planta function and to provide potential tools to improve alkaloid yields for pharmaceutical analysis. Accumulation was induced in leaf disks kept at 40ºC for three days, both by abrupt and stepwise temperature increase. Brachycerine concentration was not affected by low temperature (10ºC) exposure. Leaf disks of Psychotria carthagenensis, a species devoided of alkaloids, were also challenged by heat. Total chlorophyll, hydrogen peroxide and lipid peroxidation concentrations were determined in both species. P. carthagenensis was relatively tolerant to heat treatments which may be explained by its high anthocyanin concentration, strongly induced by heat shock of 50ºC for 6h. Brugmansia suaveolens and Brassica oleracea, pre-treated with brachycerine in concentrations equivalent to those found in P. brachyceras, had a heat shock tolerant phenotype, based on chlorophyll content. Expression of the TRYPTOPHAN DECARBOXYLASE gene, which encodes for an enzyme involved in alkaloid biosynthesis (TDC) was strongly repressed in leaf disks exposed to 40ºC for 6h, 12h e 24h, suggesting that temperature effect may occur at post-transcriptional level. Taken together, data indicate that heat exposure is an effective means to increase yields of brachycerine, whose accumulation contributes to protect against associated oxidative damage.

<p>Animal behavior observation is a widely used method of detecting when animals are ill or injured, but there are limitations to using behavioral observations. Behavioral observations can be labor-intensive, subjective and unreliable. The development of technologies such as accelerometers, which record acceleration and activity-based data in 3D space, enables faster, more accurate and quantitative methods of detecting changes in animal behavior. Previous research has demonstrated the utility of using accelerometers to detect changes in animals’ health and well-being. However, limited information is available on the use of accelerometers to detect changes in behavior due to heat stress, which is a major poultry welfare concern, or to detect changes in activity levels of turkeys. The overall objective of this study was to determine whether micro-acceleration data loggers (accelerometers) can be used to detect changes in turkeys’ activity levels and to identify changes in turkey behavior that are indicative of changes in turkey well-being. Two trials were conducted. Specific objectives for Trial 1 were to: 1) determine the effects of accelerometers and habituation to accelerometers on turkey gait and welfare, 2) determine age-related changes in gait and welfare, and 3) evaluate the validity of the accelerometers. Thirty-six male commercial turkeys were randomly assigned to one of five groups: accelerometer and habituation period (AH), accelerometer and no habituation (AN), VetRap bandage (no accelerometer) and habituation (VH), bandage (no accelerometer) and no habituation (VN), and nothing on either leg (C). Welfare was assessed prior to video-recording birds as they walked across a Tekscan® pressure pad at 8, 12 and 16 wk to determine effects of treatment on number of steps, cadence, gait time, gait distance, gait velocity, impulse, gait cycle time, maximum force, peak vertical pressure, single support time, contact time, step length, step time, step velocity, stride length, total double support time, and duty factor. Accelerometer validity and reliability were determined by comparing the number of steps detected with the accelerometer to the number of steps determined from video recordings. Several age-related changes in turkey gait were found regardless of habituation, including a slower cadence at 16 wk, shorter gait distance at 8 wk, and slower gait velocity at 16wk. Habituation to the accelerometer and bandage had limited effects on turkey gait: non-habituated turkeys (VN and AN) spent more time standing on two feet (total double support time) compared to C birds, but did not differ from habituated (VH and AH) birds. Accelerometer validity and reliability were affected by both age and treatment. Validity and reliability were lowest for non-habituated birds (AN). Precision and sensitivity of accelerometers decreased with age but were unaffected by treatment. False discovery rate increased, and accuracy and specificity decreased with age. Results demonstrated that micro-data loggers do not adversely affect turkey welfare, but habituation to wearing accelerometers affects accelerometer reliability and validity. Accelerometer validity and turkey gait are also greatly affected by the age of the turkeys. </p> <p> </p> <p>The second experiment used the validated accelerometers to assess changes in walking activity when turkeys were under an immune challenge or mild heat stress. Another objective of Experiment 2 was to identify changes in welfare and behavior associated with mild heat stress and a mild immune challenge. A total of 92 tom turkeys (trial 1: 51 turkeys; trial 2: 41 turkeys) were assigned to 3 different treatments in a crossover design: control (C; no heat stress or immune challenge), heat stress (HS), and immune challenge (IC). HS treatment was induced by slowly heating rooms to a peak temperature before slowly returning the rooms to normal temperatures. IC treatment was induced by a live-virus hemorrhagic enteritis vaccine which was added to the drinking water. Video (walking, sitting, standing, eating, drinking, preening, feather pecking, aggression and heat-stress related behavior) and accelerometer (steps/hr) data were recorded for 5 days at 10, 12, and 14 wk of age in order to gather behavior and walking activity data pre and post treatment, which occurred on day 3 of the 5 day period. Steps/hr decreased with age, treatments HS and IC had lower step counts compared to control groups, and each day proved to have a different step count regardless of whether a treatment was imposed. On the day of the imposed treatments, steps/hr were lower for both HS and IC turkeys. Welfare analysis indicated that tail and wing feather condition was worse at 14 wk compared to 10 and 12 wk. Behaviorally, the amount of time spent sitting increased as birds aged. Treatment also affected behavior: HS and IC turkeys performed less standing and walking compared to C birds on the day of the imposed treatment. Turkeys under a heat stress treatment performed more aggressive interactions and were observed performing heat-stress related behavior, including panting and sitting with their wings spread apart. </p> <p> </p> <p>Results from both trials indicated that accelerometers can be useful tools to assess walking activity of turkeys and that accelerometers have the potential to detect changes in behavior that may be associated with conditions that negatively impact turkey welfare. The process of wearing an accelerometer on the leg did not adversely affect turkey welfare, but habituation is important to ensure that accelerometers are accurately and reliably recording turkeys’ steps. In addition, it was determined that changes in behavior, such as decreased walking and standing, can be indicative of potential welfare issues, such as heat stress and an immune challenge in turkeys. Further research is needed to explore the best step threshold for particular turkey ages in order to get the most accurate data in future analysis of walking activity. Furthermore, sex differences were not a factor in these studies as only male turkeys were used which may differ from females in terms of gait and behavior under heat stress and an immune challenge. It may also be beneficial to further explore turkey gait as there were discrepancies in the literature and this study concerning age related differences in gait (duty factor). Future research should focus on the early detection potential accelerometers can provide to the turkey industry for welfare concerns. As shown by our results, walking activity decreases under both a mild heat stress and immune challenge, so future studies should now determine if this decrease in activity level is detectable before overt visual behavioral signs. If accelerometers can detect signs of stress more objectively, accurately, and quicker than visual inspection, then both farmers and researchers could benefit from utilizing these devices to improve animal welfare in the future.</p>

Les éléments transposables (ETs) sont des composants ubiquitaires des génomes eucaryotes, parfois prépondérants chez les plantes. Ce sont des séquences mobiles, potentiellement mutagènes, reconnues comme des acteurs de l’évolution des génomes. Cependant, la plupart des ETs sont aujourd’hui inactifs car réprimés par des mécanismes épigénétiques très efficaces. Néanmoins, ces derniers peuvent être relâchés par des stress, conduisant à la réactivation d’ETs. De tels stress sont-ils suffisants pour activer la transposition dans les populations naturelles? L’application répétée d’un stress peut-elle expliquer les pics d’activité transpositionnelle qui ont eu lieu en conditions naturelles? De récents travaux chez un mutant d’Arabidopsis thaliana, affecté dans une voie de répression d’ETs, le RdDM (RNA-directed DNA Methylation), ont démontré qu’un stress thermique conduisait à la réactivation transpositionnelle d’un ET. Mes travaux de thèse portent sur l’étude de riz sauvage et d’un mutant non décrit, affecté dans le RdDM, cultivés en conditions normales ou de stress thermique sur plusieurs générations. Les objectifs de mes travaux ont été de déterminer (1) l’impact de la mutation sur les différentes étapes d’activation rétrotranspositionnelle et (2) l’activation rétrotranspositionnelle en réponse à un stress thermique. Une part importante de ce travail a été consacrée au développement et à la comparaison de méthodes d’identification des mouvements d’ETs et différentes approches « omiques » ont été utilisées. La réactivation de 5 ETs dans les plantes mutantes, dont la mobilité n’avait pas encore été observée, suggère que la voie RdDM est impliquée dans le contrôle de leur répression. De plus, nos résultats confirment que les ETs ne sont pas tous réprimés par les mêmes voies de régulation. / Transposable elements (TEs) are ubiquitous among eukaryotic genomes sometimes overriding in plants. Due to their ability to replicate and transpose, they are potentially mutagenic and recognized as actors of genome evolution. However, the analysis of the transpositional activity of TEs in different plant species have shown that most of them are maintained in a transcriptionally inactive state through powerful and specific epigenetic mechanisms. These silencing processes can nevertheless be allievated under stress conditions, leading to TE reactivation. Are these stress sufficient to activate transposition in natural populations? Are repeated heat stress able to trigger transposition and therefore lead to bursts of transposition? In recent reports, reactivation of retrotransposons has been shown in Arabidopsis thaliana mutants impaired in the RdDM pathway (RNA-directed DNA Methylation) and submitted to heat stress. My PhD works reports the study of of a wild rice and a new rice mutant, affected in the RdDM, cultivated under optimal or heat stress conditions over generations. Here, we propose to determine (1) the impact of the mutation at the different levels leading to the retrotranspositional activation and (2) the retrotranspositional activity in response to heat stress. An important part of this work has been devoted to the development and the comparison of different methods to identify TE movements, and different -omics approaches have been used. The reactivation of 5 new TEs in mutants, suggests that the RdDM pathway is involved in the control of the repression of these TEs. Furthermore, our result confirm that all TEs are not regulated through the same pathways but are under the control of different lock.

O objetivo desse estudo foi avaliar se a baixa fertilidade de vacas Holandesas repetidoras de serviço [RS; comparativamente a novilhas (NOV) e vacas próximas ao pico de lactação (PL)] está associada com comprometimento da qualidade oocitária e se esta condição é agravada pelo estresse térmico. Fêmeas das três categorias foram tratadas com o mesmo protocolo de sincronização da emergência de onda folicular. Cinco dias após o início do protocolo, a ovum pick-up (OPU) foi realizada e foram avaliados (Capítulo; Cap. 1) o número de folículos ovarianos, de oócitos totais e viáveis, temperatura retal (TR), temperatura de superfície cutânea (TC) e frequência respiratória (FR). Os oócitos viáveis foram utilizados para a produção in vitro de embriões (Cap. 2) e avaliações biomoleculares (Cap. 3). No Cap. 2, foram avaliados o desenvolvimento embrionário (taxa de clivagem, de blastocisto e de eclosão) e a qualidade dos embriões produzidos (número de células e frequência de núcleos fragmentados). No Cap. 3, realizou-se a extração de RNA e DNA de parte dos oócitos coletados para a quantificação relativa e absoluta de DNA mitocondrial (mtDNA) e a avaliação da expressão de genes relacionados à replicação/transcrição do mtDNA (PPARGC1A, NRF1, POLG, POLG2, TFAM e MT-CO1), à apoptose (BAX, BCL2 e ITM2B) e ao estresse térmico (HSP90AA1 e HSPA1AB). No Cap. 4, a taxa de concepção após IATF foi avaliada em ambas as estações do ano e nas três categorias quando o mesmo protocolo de sincronização para IATF e a mesma partida de sêmen foram utilizados. No Cap. 1, vacas RS e PL aumentaram sua FR e TR no verão em relação ao inverno (P<0,0001), enquanto as NOV mantiveram essas variáveis constantes em ambas as estações. Nas três categorias houve aumento (P<0,0001) da TC no verão, mas esta sempre foi superior (P<0,001) em vacas RS e PL do que nas NOV, independente da estação. O número de folículos e de oócitos totais e viáveis declinou nas RS e PL durante o verão, mantendo-se semelhante em NOV em ambas as estações. No Cap. 2, a taxa de clivagem foi semelhante entre categorias e estações. Já a taxa de blastocisto foi reduzida no verão nas três categorias, sendo essa queda mais acentuada nas RS. A taxa de eclosão e o número de células dos blastocistos foram menores no verão (independente de categoria). Menor número de células foi observado em embriões de RS e PL (independente da estação). Além disso, a porcentagem de núcleos fragmentados foi maior nos blastocistos das RS no verão. No Cap. 3, a expressão de ITM2B e BAX foi maior em RS durante o verão. Ainda, detectaram-se indícios da ativação de mecanismos pró-apoptóticos nos oócitos de RS (maior relação BAX/BCL-2) comparadas a PL e de mecanismos compensatórios da deficiência da função mitocondrial (menor conteúdo de mtDNA e maior expressão de PPARGCC1, NRF1, TFAM, POLG e POLG2) nas RS durante o verão em relação as demais categorias. No Cap. 4, menor taxa de concepção foi observada em RS e durante o verão. Os resultados geram evidências de que o baixo desempenho reprodutivo de vacas RS durante o verão deva estar relacionado ao comprometimento da qualidade de seus oócitos, demonstrado pelo seu reduzido conteúdo de mtDNA e elevada expressão de genes relacionados a replicação/transcrição do mtDNA, apoptose e síntese de chaperonas, culminado em baixa taxa de blastocisto e alta fragmentação nuclear destes. / The aims of the present study were to evaluate whether lower fertility of repeat-breeder (RB) Holstein cows [compared to peak lactation cows (PL) and heifers (H)] is associated with oocyte quality and whether this condition is aggravated by summer heat stress. Females of the three categories were treated with same protocol for synchronization of follicular wave emergence during summer and winter. Five days after the protocol onset, the ovum pick-up (OPU) was performed. The following variables were evaluated in Chapter 1: number of ovarian follicles before OPU, number of total and viable oocytes, rectal temperature (RT), cutaneous temperature (CT) and respiration rate (RR). Viable oocytes were sent forThe aims of the present study were to evaluate whether lower fertility of repeat-breeder (RB) Holstein cows [compared to peak lactation cows (PL) and heifers (H)] is associated with oocyte quality and whether this condition is aggravated by summer heat stress. Females of the three categories were treated with same protocol for synchronization of follicular wave emergence during summer and winter. Five days after the protocol onset, the ovum pick-up (OPU) was performed. The following variables were evaluated in Chapter 1: number of ovarian follicles before OPU, number of total and viable oocytes, rectal temperature (RT), cutaneous temperature (CT) and respiration rate (RR). Viable oocytes were sent for in vitro embryo production (Chapter 2) and bimolecular evaluation (Chapter 3). In Chapter 2, embryo development (rates of cleavage, blastocyst and hatching) and quality (total number of nuclei and frequency of nuclear fragmentation) were assessed. In Chapter 3, part of the oocytes were subjected to DNA and RNA extraction to allow relative and absolute quantification of mitochondrial DNA (mtDNA), and the evaluation of the expression of genes related to mtDNA replication/transcription (PPARGC1A, NRF1, POLG, POLG2, TFAM and MT-CO1), apoptosis (BAX, BCL2 and ITM2B) and heat stress (HSP90AA1 e HSPA1AB). In Chapter 4, RB, PL and H were subjected to same protocol for fixed-time AI using the same batch of semen of a single sire in order to evaluate their P/AI during summer and winter. In Chapter 1, RB and PL had increased (P<0.0001) RR and RT during summer compared to winter; while H maintained similar RR and RT in both seasons. CT was greater (P<0.0001) during summer than winter in all categories, but it was always higher (P<0.001) in RB and PL than H, regardless of season. The numbers of follicles and total and viable oocytes were lower in RB and PL during summer than winter, and maintained stable in H in both seasons. In Chapter 2, cleavage rate was similar among categories and between seasons. However, blastocyst rate was invariably reduced during summer, but more pronouced in RB. Hatching rate and the total number of nuclei were decreased during summer, regardless of category. Lower number of nuclei was observed in RB and PL embryos compared to H, regardless of the season. Furthermore, the percentage of fragmented nuclei was greater in RB blastocysts during the summer. In Chapter 3, expressions of ITM2B and BAX were greater in RB oocytes collected during summer. Also, the activation of pro-apoptotic mechanisms (greater BAX/BCL2 ratio) was suggested in RB heat stressed-oocytes compared with PL. Activation of compensatory mechanisms of deficient mitochondrial function (low number of copies of mtDNA and increased expression of PPARGCC1, NRF1, TFAM, POLG and POLG2) were also observed in RB heat stressed-oocytes compared with PL and H. In Charpter 4, lower P/AI was observed in RB and under summer heat stress. These data provide evidences that the lower reproduction performance observed in RB during heat stress may be due to impaired oocyte quality, as shown by their reduced mtDNA content and upregulation of several genes related to mtDNA replication/transcription, apoptosis and chaperones synthesis, resulting in lower blastocyst rate and higher nuclear fragmentation of embryos.

A alta variabilidade na resposta aos tratamentos superovulatórios e na produção de embriões tem sido relacionada a causas multifatoriais. Além disso, são restritas as informações que relacionam fatores correlatos ao embrião à concepção. Dessa forma, o objetivo do presente estudo foi avaliar a influência de variáveis relacionadas às doadoras (categoria animal e época do ano de produção do embrião) na eficiência de programas de superovulação (SOV), assim como na eficiência reprodutiva de receptoras em programas de transferência de embrião. Foram avaliados dados de 1.562 protocolos de SOV (609 em vacas em lactação e 953 em novilhas da raça Holandesa) e 4.076 transferências de embrião (receptoras Holandesas em lactação). A taxa de SOV (número de doadoras com dois ou mais CL) foi semelhante entre novilhas e vacas em lactação (89,7 vs. 91,9%, respectivamente; P = 0,26). A época do ano, também, não influenciou a taxa de SOV (época quente = 89,3% vs. época não quente = 92,2%; P = 0,09). Doadoras lactantes apresentaram maior número de CL (10,6 ± 0,6 vs. 7,5 ± 0,4; P < 0,0001), de estruturas recuperadas (7,6 ± 0,6 vs. 4,6 ± 0,4; P < 0,0001) e taxa de recuperação (77,6 vs. 58,7%; P < 0,0001) que novilhas. Doadoras superovuladas na época quente apresentaram menor número de CL (8,3 ± 0,5 vs. 9,7 ± 0,5; P = 0,03), de estruturas recuperadas (5,3 ± 0,5 vs. 6,7 ± 0,5; P = 0,04) e taxa de recuperação (65,7 vs. 72,3 %; P = 0,007) que doadoras superovuladas na época não quente. A taxa de fertilização (47,9 vs. 82,4%; P < 0,0001), de embriões viáveis (31,5 vs. 67,4%; P < 0,0001) e embriões viáveis grau I e II (15,4 vs. 42,1%; P < 0,0001) foram inferiores em doadoras lactantes. Semelhantemente, inferiores taxas de embriões viáveis (44,6 vs. 54,0%; P = 0,002) e embriões viáveis grau I e II (21,4 vs. 32,8%; P < 0,0001) foram verificadas durante a época quente do ano. No entanto, a queda na taxa de embriões grau I e II durante a época quente foi mais acentuada em doadoras lactantes (21,7 e 10,7%), quando comparada à observada em novilhas (46,2 e 38,1%; P = 0,02). Apesar da época do ano não ter influenciado a taxa de fertilização (época quente = 64,9 vs. época não quente = 70,0%; P = 0,07), foi observado relação negativa com a temperatura máxima média durante os 15 dias do protocolo de SOV (P = 0,006). A taxa de embriões viáveis também se mostrou negativamente relacionada com a temperatura máxima durante os 15 dias do protocolo de SOV (P = 0,03). O número de embriões viáveis foi semelhante entre as categorias (novilhas = 3,8 ± 0,3 vs. vacas em lactação = 3,3 ± 0,4; P = 0,16), porém foi inferior quando produzido durante a época quente (2,8 ± 0,3 vs. 4,4 ± 0,4; P = 0,03). A taxa de concepção dos embriões oriundos de doadoras em lactação foi maior aos 31 (36,0 vs. 30,7%; P = 0,001) e aos 45 dias de gestação (28,3 vs. 23,1%; P = 0,001). No entanto, a categoria da doadora não influenciou a perda gestacional (novilhas = 18,2% vs. vacas em lactação = 16,6%; P = 0,49). Ainda, as taxas de concepção aos 31 dias (30,5 vs. 31,7%: P = 0,47) e aos 45 dias (25,3 vs. 25,1%; P = 0,94) e perda gestacional (17,4 vs. 22,1%; P = 0,07) das receptoras não diferiram conforme a época de produção dos embriões, época quente e não quente, respectivamente. Também não foi verificado diferença nas taxas de concepção aos 31 dias (31,5 vs. 30,5%: P = 0,66) e aos 45 dias (25,1 vs. 25,4%; P = 0,89) e perda gestacional (18,4 vs. 16,5%; P = 0,49) das receptoras conforme a época de transferência dos embriões, época quente e não quente, respectivamente. Porém, a taxa de concepção aos 31 (P = 0,02) e aos 45 dias (P = 0,02) tiveram relação negativa com a média da temperatura máxima entre o estro e a TE. Em conclusão, apesar das doadoras em lactação apresentarem maior resposta superovulatória, as novilhas apresentaram semelhante número de embriões viáveis, porém maior taxa de embriões viáveis. A resposta ao tratamento superovulatório e a produção de embriões foram inferiores durante a época quente do ano. Embriões originados de doadoras Holandesas lactantes apresentaram maior taxa de concepção aos 31 e aos 45 dias de gestação do que embriões originados de novilhas. Apesar da época do ano não influenciar na taxa de concepção e na perda gestacional, verificou-se relação negativa da temperatura máxima entre o estro e a TE na taxa de concepção. / The high variability in the response to superovulatory treatments and embryo production has been related to multifactorial causes. Furthermore, there are restricted data that correlates factors related to the embryo to the conception. Thus, the objective of the present study was to evaluate the influence of variables related to donors (animal type and season of embryo production) in the efficiency of superovulation (SOV) programs and reproductive performance of dairy cows submitted to embryo transfer. We evaluated data from 1,562 SOV protocols (609 in lactating Holstein cows and 953 in heifers) and 4,076 embryo transfers (lactating Holstein recipient). The SOV rate (number of donor with two or more CL) was similar among lactating cows and heifers (89.7 vs. 91.9%, respectively; P = 0.26). Also, the season did not influence the SOV rate (warm season = 89.3% vs. not warm season = 92.2%; P = 0.09). Lactating donor had higher number of CL (10.6 ± 0.6 vs. 7.5 ± 0.4; P <0.0001), of recovered structures (7.6 ± 0.6 vs. 4.6 ± 0.4; P <0.0001) and recovery rate (77.6 vs. 58.7%; P <0.0001) than heifers. Donors superovulated during warm season had fewer number of CL (8.3 ± 0.5 vs. 9.7 ± 0.5; P = 0.03), of recovered structures (5.3 ± 0.5 vs. 6, 7 ± 0.5; P = 0.04) and recovery rate (65.7 vs. 72.3%; P = 0.007). The fertilization rate (47.9 vs. 82.4%; P <0.0001), viable embryos rate (31.5 vs. 67.4%; P <0.0001) and embryos grade I and II rate (15.4 vs. 42.1%; P <0.0001) were lower in lactating donor. Similarly, lower viable embryos rate (44.6 vs. 54.0%; P = 0.002) and embryos grade I and II rate (21.4 vs. 32.8%; P <0.0001) were observed during the warm season. However, the decrease in the embryos grade I and II rate during the warm period was more pronounced in lactating donors (21.7 and 10.7%) compared to that observed in heifers (46.2 and 38.1%; P = 0.02). Although the season did not influence fertilization rate (warm season = 64.9 vs. not warm season = 70.0%, P = 0.07), it was observed a negative relationship with the average maximum temperature during the 15 days of the SOV protocol (P = 0.006). The viable embryos rate was also negatively correlated with the maximum temperature during the 15 days of the SOV protocol (P = 0.03). The number of viable embryos was similar between categories (heifers = 3.8 ± 0.3 vs. lactating cows = 3.3 ± 0.4; P = 0.16), but was lower when produced during the warm season (2.8 ± 0.3 vs. 4.4 ± 0.4; P = 0.03). The conception rate of embryos from lactating donors was higher at 31 (36.0 vs. 30.7%; P = 0.001) and at 45 days of pregnancy (28.3 vs. 23.1%; P = 0.001). However, the donor category did not influence pregnancy loss (heifers = 18.2% vs. lactating cows = 16.6%; P = 0.49). Still, the recipients conception rate at 31 days (30.5 vs. 31.7%; P = 0.47) and at 45 days of pregnancy (25.3 vs. 25.1%; P = 0.94) and pregnancy loss (17.4 vs. 22.1%; P = 0.07) did not differ according to the embryo production season; warm and not warm season, respectively. Also,no difference was verified in recipients conception rates at 31 days (31.5 vs. 30.5%; P = 0.66) and at 45 days (25.1 vs. 25.4%; P = 0.89) and pregnancy loss (18.4 vs. 16.5%; P = 0.49) according to the embryo transfer season; warm and not warm season, respectively. However, conception rate at 31 (P = 0,02) and 45 days (P = 0.02) had a negative relationship with the average maximum temperature between estrus and TE. In conclusion, despite the lactating donors had higher superovulatory response, heifers presented similar number of viable embryos, but higher viable embryos rate. The superovulatory response and the embryo production were lower during the warm season. Embryos from lactating Holstein donors had higher conception rate at 31 and 45 days of gestation than embryos from heifers. Although the season did not influence the conception and pregnancy loss rates, there was a negative relationship between average maximum temperature during estrus and TE and conception rate.

O estresse é uma realidade na produção avícola mundial. Sabe-se que ambientes estressores prejudicam o bem-estar, os parâmetros produtivos e a imunidade de frangos de corte. Sabe-se, também, que o estresse por calor diminui a atividade de macrófagos em frangos de corte e, que existem, inúmeros estressores ambientais que insidem sobre a produção animal e podem aumentar a susceptibilidade às doenças. A Salmonella spp. é uma das maiores zoonoses do mundo, causando mais de 1 bilhão de casos de infecção. Nesse sentido, o presente trabalho analisa os efeitos do estresse por calor (31±1°C) sobre os índices zootécnicos, a imunidade, a invasão bacteriana e a integridade intestinal em frangos de corte infectados com Salmonella enteritidis; os dados obtidos foram discutidos dentro de uma perspectiva neuroimune. Os frangos foram divididos em quatro grupos: 1) Controle (C); 2) Estresse por Calor a 31±1 °C (HS31°C); 3) Controle infectados com Salmonella enteritidis (Controle Positivo [PC]) e; 4) Estresse por calor a 31±1 °C e infectados com Salmonella (PHS31°C). Nossos resultados mostraram que o estresse por calor em uma situação de infecção experimental por Salmonella enteritidis (grupo PHS31°C) 1) diminuiu os índices zootécnicos; especificamente, diminuiu o ganho de peso, consumo de alimento e a conversão alimentar; 2) diminuiu os níveis plasmáticos de INF-&gamma; e IgA; 3) diminuiu a expressão de, IL-6 e IL-12 em baço e diminui IL1- &beta;, IL-10 e TGF-&beta; em tonsila cecal; 4) diminuiu a expressão de AvBD-4 e AvBD-6 em tonsila cecal e; 5) diminuiu a expressão de TLR-2 em baço e tonsila cecal. Observamos, também, 6) aumento dos níveis séricos de corticosterona nos animais dos grupos HS31°C e PHS31°C e; 7) piora no quadro de enterite produzida pela Salmonella enteritidis, quando os animais foram estressados por calor, caracterizando-se uma enterite moderada ao longo de todo o intestino delgado. Finalmente, 8) observamos que o estresse por calor aumentou a migração de Salmonella enteritidis para baço das aves do grupo PHS31°C, porém esse aumento não foi observado no fígado; observamos, também, presença de Salmonella na medula osssea dos animais estressados e infectado com essa bactéria. Os dados obtidos sugerem que a somatória dos fatores estresse por calor e infecção por Samonella prejudicou os parâmetros produtivos, a integridade intestinal, a imunidade e, em especial a ativação e atividade de macrófagos, possibilitando um aumento da migração de Salmonella enteritidis para o baço e medula óssea dos frangos de corte. Neste sentido, o estresse por calor teria prejudicado a qualidade da barreira imune intestinal, via ativação do eixo HPA e aumento dos níveis de corticosterona, diminuindo a imunidade inata proporcionando a migração das bactérias patogênicas através da mucosa intestinal para o baço e a medula óssea das aves estressadas. / Stress is a reality in the world poultry production. Environmental stressors impair both welfare, performance parameters and immunity in broiler chickens. Heat stress decreases macrophage activity in broiler chickens and many environmental stressors that impact animal production increases animal\'s susceptibility to diseases. Samonella spp is one of the most endemic zoonotic diseases of the world, inducing more than 1 billion infection cases per year. In this way, we studied the effects of 31±1°C heat stress on performance parameters, immunity, bacteria invasion and intestinal integrity in broiler chickens experimentally infected with Salmonella enteritidis; the data were discussed under a neuroimmune perspective. The broiler chickens were divided into four different groups: 1) Control group (C); 2) 31±1 °C heat stressed group (HS31°C); 3) Control group infected with Salmonella enteritidis Positive control (PC) and; 4) 31±1 °C heat stressed and Salmonella enteritidis infected group (PHS31°C). We showed the heat stress applied in the course of Salmonella enteritidis infection (PHS31°C group) decreased poultry performance parameters; specifically, it decreased the body weight gain, the feed intake and the food conversion; 2) decresead INF-&gamma; and IgA plasmatic levels; 3) decreased the mRNA expression of IL-6 and IL- 12 in spleen and the mRNA expression of IL1-&beta;, IL-10 and TGF-&beta; in cecal tonsil; 4) decreased the mRNA expression of AvBD-4 and AvBD-6 in cecal tonsil and; 5) decreased the mRNA expression of TLR-2 in spleen and cecal tonsil. We also observed 6) an increase in corticosterone serum levels in the animals of the HS31°C and the PHS31°C groups and, 7) more severe intestinal inflamation produced by Salmonella enteritidis in heat stressed chickens, characterized by a moderate enteritis throughout all the small intestine mucosa (PHS31°C group). Finally, 8) we showed that the heat stress increased splenic Salmonella enteritides invasion in PHS31°C broiler chickens; we also observed the presence of Salmonella in the bone marrow of stressed and infected broiler chickens. These data suggest that heat stress and Salmonella infection working together impair chicken\'s performance parameters, intestinal integrity and immunity (specially the macrophage activity), increasing ate the same time splenic and bone marrow Salmonella enteritidis invasion. Thus, heat stress could have impared the intestinal immunity barrier quality, via HPA axis activation and corticosterone serum levels release, decreasing the inate immunity and, providing pathogenic bacteria migration through the intestinal mucosa for spleen and bone marrow of the heat stressed chickens.

A alta variabilidade na resposta aos tratamentos superovulatórios e na produção de embriões tem sido relacionada a causas multifatoriais. Além disso, são restritas as informações que relacionam fatores correlatos ao embrião à concepção. Dessa forma, o objetivo do presente estudo foi avaliar a influência de variáveis relacionadas às doadoras (categoria animal e época do ano de produção do embrião) na eficiência de programas de superovulação (SOV), assim como na eficiência reprodutiva de receptoras em programas de transferência de embrião. Foram avaliados dados de 1.562 protocolos de SOV (609 em vacas em lactação e 953 em novilhas da raça Holandesa) e 4.076 transferências de embrião (receptoras Holandesas em lactação). A taxa de SOV (número de doadoras com dois ou mais CL) foi semelhante entre novilhas e vacas em lactação (89,7 vs. 91,9%, respectivamente; P = 0,26). A época do ano, também, não influenciou a taxa de SOV (época quente = 89,3% vs. época não quente = 92,2%; P = 0,09). Doadoras lactantes apresentaram maior número de CL (10,6 ± 0,6 vs. 7,5 ± 0,4; P < 0,0001), de estruturas recuperadas (7,6 ± 0,6 vs. 4,6 ± 0,4; P < 0,0001) e taxa de recuperação (77,6 vs. 58,7%; P < 0,0001) que novilhas. Doadoras superovuladas na época quente apresentaram menor número de CL (8,3 ± 0,5 vs. 9,7 ± 0,5; P = 0,03), de estruturas recuperadas (5,3 ± 0,5 vs. 6,7 ± 0,5; P = 0,04) e taxa de recuperação (65,7 vs. 72,3 %; P = 0,007) que doadoras superovuladas na época não quente. A taxa de fertilização (47,9 vs. 82,4%; P < 0,0001), de embriões viáveis (31,5 vs. 67,4%; P < 0,0001) e embriões viáveis grau I e II (15,4 vs. 42,1%; P < 0,0001) foram inferiores em doadoras lactantes. Semelhantemente, inferiores taxas de embriões viáveis (44,6 vs. 54,0%; P = 0,002) e embriões viáveis grau I e II (21,4 vs. 32,8%; P < 0,0001) foram verificadas durante a época quente do ano. No entanto, a queda na taxa de embriões grau I e II durante a época quente foi mais acentuada em doadoras lactantes (21,7 e 10,7%), quando comparada à observada em novilhas (46,2 e 38,1%; P = 0,02). Apesar da época do ano não ter influenciado a taxa de fertilização (época quente = 64,9 vs. época não quente = 70,0%; P = 0,07), foi observado relação negativa com a temperatura máxima média durante os 15 dias do protocolo de SOV (P = 0,006). A taxa de embriões viáveis também se mostrou negativamente relacionada com a temperatura máxima durante os 15 dias do protocolo de SOV (P = 0,03). O número de embriões viáveis foi semelhante entre as categorias (novilhas = 3,8 ± 0,3 vs. vacas em lactação = 3,3 ± 0,4; P = 0,16), porém foi inferior quando produzido durante a época quente (2,8 ± 0,3 vs. 4,4 ± 0,4; P = 0,03). A taxa de concepção dos embriões oriundos de doadoras em lactação foi maior aos 31 (36,0 vs. 30,7%; P = 0,001) e aos 45 dias de gestação (28,3 vs. 23,1%; P = 0,001). No entanto, a categoria da doadora não influenciou a perda gestacional (novilhas = 18,2% vs. vacas em lactação = 16,6%; P = 0,49). Ainda, as taxas de concepção aos 31 dias (30,5 vs. 31,7%: P = 0,47) e aos 45 dias (25,3 vs. 25,1%; P = 0,94) e perda gestacional (17,4 vs. 22,1%; P = 0,07) das receptoras não diferiram conforme a época de produção dos embriões, época quente e não quente, respectivamente. Também não foi verificado diferença nas taxas de concepção aos 31 dias (31,5 vs. 30,5%: P = 0,66) e aos 45 dias (25,1 vs. 25,4%; P = 0,89) e perda gestacional (18,4 vs. 16,5%; P = 0,49) das receptoras conforme a época de transferência dos embriões, época quente e não quente, respectivamente. Porém, a taxa de concepção aos 31 (P = 0,02) e aos 45 dias (P = 0,02) tiveram relação negativa com a média da temperatura máxima entre o estro e a TE. Em conclusão, apesar das doadoras em lactação apresentarem maior resposta superovulatória, as novilhas apresentaram semelhante número de embriões viáveis, porém maior taxa de embriões viáveis. A resposta ao tratamento superovulatório e a produção de embriões foram inferiores durante a época quente do ano. Embriões originados de doadoras Holandesas lactantes apresentaram maior taxa de concepção aos 31 e aos 45 dias de gestação do que embriões originados de novilhas. Apesar da época do ano não influenciar na taxa de concepção e na perda gestacional, verificou-se relação negativa da temperatura máxima entre o estro e a TE na taxa de concepção. / The high variability in the response to superovulatory treatments and embryo production has been related to multifactorial causes. Furthermore, there are restricted data that correlates factors related to the embryo to the conception. Thus, the objective of the present study was to evaluate the influence of variables related to donors (animal type and season of embryo production) in the efficiency of superovulation (SOV) programs and reproductive performance of dairy cows submitted to embryo transfer. We evaluated data from 1,562 SOV protocols (609 in lactating Holstein cows and 953 in heifers) and 4,076 embryo transfers (lactating Holstein recipient). The SOV rate (number of donor with two or more CL) was similar among lactating cows and heifers (89.7 vs. 91.9%, respectively; P = 0.26). Also, the season did not influence the SOV rate (warm season = 89.3% vs. not warm season = 92.2%; P = 0.09). Lactating donor had higher number of CL (10.6 ± 0.6 vs. 7.5 ± 0.4; P <0.0001), of recovered structures (7.6 ± 0.6 vs. 4.6 ± 0.4; P <0.0001) and recovery rate (77.6 vs. 58.7%; P <0.0001) than heifers. Donors superovulated during warm season had fewer number of CL (8.3 ± 0.5 vs. 9.7 ± 0.5; P = 0.03), of recovered structures (5.3 ± 0.5 vs. 6, 7 ± 0.5; P = 0.04) and recovery rate (65.7 vs. 72.3%; P = 0.007). The fertilization rate (47.9 vs. 82.4%; P <0.0001), viable embryos rate (31.5 vs. 67.4%; P <0.0001) and embryos grade I and II rate (15.4 vs. 42.1%; P <0.0001) were lower in lactating donor. Similarly, lower viable embryos rate (44.6 vs. 54.0%; P = 0.002) and embryos grade I and II rate (21.4 vs. 32.8%; P <0.0001) were observed during the warm season. However, the decrease in the embryos grade I and II rate during the warm period was more pronounced in lactating donors (21.7 and 10.7%) compared to that observed in heifers (46.2 and 38.1%; P = 0.02). Although the season did not influence fertilization rate (warm season = 64.9 vs. not warm season = 70.0%, P = 0.07), it was observed a negative relationship with the average maximum temperature during the 15 days of the SOV protocol (P = 0.006). The viable embryos rate was also negatively correlated with the maximum temperature during the 15 days of the SOV protocol (P = 0.03). The number of viable embryos was similar between categories (heifers = 3.8 ± 0.3 vs. lactating cows = 3.3 ± 0.4; P = 0.16), but was lower when produced during the warm season (2.8 ± 0.3 vs. 4.4 ± 0.4; P = 0.03). The conception rate of embryos from lactating donors was higher at 31 (36.0 vs. 30.7%; P = 0.001) and at 45 days of pregnancy (28.3 vs. 23.1%; P = 0.001). However, the donor category did not influence pregnancy loss (heifers = 18.2% vs. lactating cows = 16.6%; P = 0.49). Still, the recipients conception rate at 31 days (30.5 vs. 31.7%; P = 0.47) and at 45 days of pregnancy (25.3 vs. 25.1%; P = 0.94) and pregnancy loss (17.4 vs. 22.1%; P = 0.07) did not differ according to the embryo production season; warm and not warm season, respectively. Also,no difference was verified in recipients conception rates at 31 days (31.5 vs. 30.5%; P = 0.66) and at 45 days (25.1 vs. 25.4%; P = 0.89) and pregnancy loss (18.4 vs. 16.5%; P = 0.49) according to the embryo transfer season; warm and not warm season, respectively. However, conception rate at 31 (P = 0,02) and 45 days (P = 0.02) had a negative relationship with the average maximum temperature between estrus and TE. In conclusion, despite the lactating donors had higher superovulatory response, heifers presented similar number of viable embryos, but higher viable embryos rate. The superovulatory response and the embryo production were lower during the warm season. Embryos from lactating Holstein donors had higher conception rate at 31 and 45 days of gestation than embryos from heifers. Although the season did not influence the conception and pregnancy loss rates, there was a negative relationship between average maximum temperature during estrus and TE and conception rate.

abstract: This study investigated the effect of environmental heat stress on physiological and performance measures during a ~4 mi time trial (TT) mountain hike in the Phoenix metropolitan area. Participants (n = 12; 7M/5F; age 21.6 ± 2.47 [SD]) climbed ‘A’ mountain (~1 mi) four times on a hot day (HOT; wet bulb globe temperature [WBGT] = 31.6°C) and again on a moderate day (MOD; WBGT = 19.0°C). Physiological and performance measures were made before and throughout the course of each hike. Mean pre-hike hydration status (urine specific gravity [USG]) indicated that participants began both HOT and MOD trials in a euhydrated state (1.016 ± 0.010 and 1.010 ± 0.008, respectively) and means did not differ significantly between trials (p = .085). Time trial performance was impaired by -11% (11.1 minutes) in the HOT trial (105 ± 21.7 min), compared to MOD (93.9 ± 13.1 min) (p = .013). Peak core temperatures were significantly higher in HOT (38.5 ± 0.36°C) versus MOD (38.0 ± 0.30°C) with progressively increasing differences between trials over time (p < .001). Peak ratings of perceived exertion were significantly higher in HOT (14.2 ± 2.38) compared to MOD (11.9 ± 2.02) (p = .007). Relative intensity (percent of age-predicted maximal heart rate [HR]), estimated absolute intensity (metabolic equivalents [METs]), and estimated energy expenditure (MET-h) were all increased in HOT, but not significantly so. The HOT condition reduced predicted maximal aerobic capacity (CRFp) by 6% (p = .026). Sweat rates differed significantly between HOT (1.38 ± 0.53 L/h) and MOD (0.84 ± 0.27 L/h) (p = .01). Percent body mass loss (PBML) did not differ significantly between HOT (1.06 ± 0.95%) and MOD (0.98 ± 0.84%) (p = .869). All repeated measures variables showed significant between-subjects effects (p < .05), indicating individual differences in response to test conditions. Heat stress was shown to negatively affect physiological and performance measures in recreational mountain hikers. However, considerable variation exists between individuals, and the degree of physiological and performance impairment is probably due, in part, to differences in aerobic fitness and acclimatization status rather than pre- or during-performance hydration status. / Dissertation/Thesis / Masters Thesis Exercise and Wellness 2019