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Background: Bungarus multicinctus is one of the most dangerous venomous snakes prone to cardiopulmonary damage with extremely high mortality. In our previous work, we found that glutamine (Gln) and glutamine synthetase (GS) in pig serum were significantly reduced after Bungarus multicinctus bite. In the present study, to explore whether there is a link between the pathogenesis of cardiopulmonary injury and Gln metabolic changes induced by Bungarus multicinctus venom. We investigated the effect of Gln supplementation on the lung and heart function after snakebite. Methods: We supplemented different concentrations of Gln to mice that were envenomated by Bungarus multicinctus to observe the biological behavior, survival rate, hematological and pathological changes. Gln was supplemented immediately or one hour after the venom injection, and then changes in Gln metabolism were analyzed. Subsequently, to further explore the protective mechanism of glutamine on tissue damage, we measured the expression of heat-shock protein70 (HSP70), NF-κB P65, P53/PUMA by western blotting and real-time polymerase in the lung and heart. Results: Gln supplementation delayed the envenoming symptoms, reduced mortality, and alleviated the histopathological changes in the heart and lung of mice bitten by Bungarus multicinctus. Additionally, Gln increased the activity of glutamine synthetase (GS), glutamate dehydrogenase (GDH) and glutaminase (GLS) in serum. It also balanced the transporter SLC7A11 expression in heart and lung tissues. Bungarus multicinctus venom induced the NF-κB nuclear translocation in the lung, while the HO-1 expression was suppressed. At the same time, venom activated the P53/PUMA signaling pathway and the BAX expression in the heart. Gln treatment reversed the above phenomenon and increased HSP70 expression. Conclusion: Gln alleviated the glutamine metabolism disorder and cardiopulmonary damage caused by Bungarus multicinctus venom. It may protect lungs and heart against venom by promoting the expression of HSP70, inhibiting the activation of NF-κB and P53/PUMA, thereby delaying the process of snake venom and reducing mortality. The present results indicate that Gln could be a potential treatment for Bungarus multicinctus bite.

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Short-term grazing behavior variables are sensitive to the canopy structure and have an impact on daily forage intake. This study evaluated the effect of pre- and post-grazing canopy heights on the forage harvesting process at a patch scale in a mixture of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. syn. Urochloa brizantha R.D. Webster cv. Marandu (palisade grass) and Arachis pintoi Krapov. & W.C. Greg. cv. Belomonte (forage peanut). Treatments were allocated to a split-plot arrangement in a completely randomized design. The plots, in their entirety, consisted of two pre-grazing canopy heights: 25 cm (CH25) and 35 cm (CH35); subplots consisted of three levels of defoliation severity: no defoliation (DS0); 20% depletion of pre-grazing canopy height (DS20); and 40% depletion of pre-grazing canopy height (DS40), with eight replications. Heifers were allowed to graze the patches (0.7 × 0.7 m) and their grazing behavior was recorded. Canopy structure measurements were taken both before and after grazing. Patches from CH35 presented greater stem mass for grass (p = 0.001) and legume (p = 0.002) than did patches from CH25. Bite rate, bite mass and instantaneous intake rate were greater for CH25 than for CH35 (p < 0.001, p = 0.068, and p = 0.074), and bite mass and instantaneous intake rate were lower for DS20 compared to DS0 (p = 0.032 and p = 0.016). Greater stem mass in the grazing strata negatively influenced the instantaneous intake rate.

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In Brazil, snakebites are often cited as a cause of mortality in ruminants, but there are discrepancies in the literature regarding its actual prevalence, either by lack of diagnosis or by mistakes in the differential diagnosis. Among the factors that hinder the diagnosis are included the inconsistencies to distinguish between accidents caused by Bothrops and Crotalus, responsible for over 90% of the cases. For the diagnosis of accidents involving Lachesis muta, both the neurotropic and the proteolytic/hemolytic effects must be considered, similar to what is described in Crotalus scutulatus. This article describes the main clinical, pathological, and laboratory findings observed in envenoming by the aforementioned snakes and suggests procedures for establishing the diagnosis and differential diagnosis starting from a logical sequence, based on epidemiological evidence, clinical, laboratory, and pathological findings.

No Brasil, acidentes ofídicos são frequentemente citados como causa de mortalidade em ruminantes, mas existem discrepâncias em relação a sua atual prevalência, seja por falta de diagnóstico ou por erros no diagnóstico diferencial. Entre os fatores que dificultam o diagnóstico estão as inconsistências para distinguir entre os acidentes causados por Bothrops e Crotalus, responsáveis por mais de 90% dos casos. Para o diagnóstico de envenenamentos por Lachesis muta, devem ser considerados os efeitos neurotrópico e proteolítico/hemolíticos concomitantes, a exemplo do que ocorre com algumas cascavéis norte-americanas (Crotalus scutulatus, entre elas). Este artigo descreve os principais achados clinicopatológicos e laboratoriais observados em casos de envenenamento pelas serpentes citadas e sugere um roteiro simplificado para o estabelecimento do diagnóstico e diagnóstico diferencial, a partir de uma sequência lógica, baseada em evidências epidemiológicas e achados clínicos, laboratoriais e patológicos.

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Short-term grazing behavior variables are sensitive to the canopy structure and have an impact on daily forage intake. This study evaluated the effect of pre- and post-grazing canopy heights on the forage harvesting process at a patch scale in a mixture of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. syn. Urochloa brizantha R.D. Webster cv. Marandu (palisade grass) and Arachis pintoi Krapov. & W.C. Greg. cv. Belomonte (forage peanut). Treatments were allocated to a split-plot arrangement in a completely randomized design. The plots, in their entirety, consisted of two pre-grazing canopy heights: 25 cm (CH25) and 35 cm (CH35); subplots consisted of three levels of defoliation severity: no defoliation (DS0); 20% depletion of pre-grazing canopy height (DS20); and 40% depletion of pre-grazing canopy height (DS40), with eight replications. Heifers were allowed to graze the patches (0.7 × 0.7 m) and their grazing behavior was recorded. Canopy structure measurements were taken both before and after grazing. Patches from CH35 presented greater stem mass for grass (p = 0.001) and legume (p = 0.002) than did patches from CH25. Bite rate, bite mass and instantaneous intake rate were greater for CH25 than for CH35 (p < 0.001, p = 0.068, and p = 0.074), and bite mass and instantaneous intake rate were lower for DS20 compared to DS0 (p = 0.032 and p = 0.016). Greater stem mass in the grazing strata negatively influenced the instantaneous intake rate.

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Background: Although scorpionism is recorded worldwide, some regions such as Iran present a higher incidence. Due to the great prevalence of scorpion stings in Khuzestan province, southwestern Iran, the present study examined the relationship between different climate parameters and the scorpion sting rate in this area from April 2010 to March 2015. Methods: In this cross-sectional descriptive-analytical study, we considered all scorpion sting cases recorded in the Department of Infectious Diseases, Ahvaz Jundishapur University of Medical Sciences. Data were analyzed using statistics, frequency distribution and Pearson's correlation coefficient. Results: A total of 104,197 cases of scorpion stings was recorded from 2010 to 2015. The cumulative incidence of scorpion sting was 2.23%. The spatial distribution of scorpion stings showed that most cases occurred in the Dehdez district (4,504 scorpion stings/100,000 inhabitants) and the Masjed Soleyman county (4,069 scorpion stings/100,000 inhabitants). A significant association was found between climate factors (temperature, evaporation rate, sunshine duration, humidity, and precipitation) and the scorpion sting rate. An increase in rainfall and humidity coincided with a reduction in scorpion stings whereas an increase in temperature, evaporation, and sunshine duration was accompanied by a growth of scorpion stings. No significant correlation was found between wind velocity/direction and the incidence rate of stings. Moreover, the seasonal peak incidence of scorpion stings was recorded in summer (an average of 8,838 cases) and the lowest incidence was recorded during winter (an average of 1,286 cases). The annual trend of scorpion sting cases decreased during the period from 2010 to 2015. Conclusion: Climate variables can be a good index for predicting the incidence of scorpion stings in endemic regions. Since they occur mostly in the hot season, designing preventive measures in the counties and districts with a high incidence of scorpion stings such as Dehdez and Masjed Soleyman can minimize mortality and other burdens.(AU)

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The objective of this study was to evaluate the feeding and agonistic behavior of Quarter Horses kept in different types of stalls in the semiarid region of Minas Gerais. A completely randomized design with two treatments (two types of stalls) and seven replicates (seven days of evaluation) was used. Four Quarter Horse mares and four stallions were used per treatment. Behavioral observations were made at 10-minute intervals for 24 hours. The stall environment was characterized by the following variables: air temperature, relative humidity, and black globe temperature for subsequent estimation of the wet-bulb globe temperature. Feeding behavior variables included: time spent eating concentrate and time spent eating roughage (hours), bite rate (bites/min), and the number of daily bites (bites/day). Zinc-roofed stalls had higher air temperatures than clay-roofed stalls and the external environment, averaging 28.2, 27.0, and 27.4 ºC, respectively, while relative humidity was significantly lower in the external environment (65.80%). Horses housed in zinc-roofed stalls had longer feeding times (8.32 h) than animals kept in clay-roofed stalls (7.22 h). Approximately 94% of the total feeding time was spent eating roughage and 73% of the time was spent resting and walking, regardless of the covering type. Although environmental variables showed thermal discomfort, the roofing material did not alter the feeding behavior of stabled horses in the semiarid region of Minas Gerais, suggesting an adaptation to the studied conditions. The feeding frequency should be increased to avoid a long resting time.

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Aiming to compare integrated crop, livestock (ICL) and forest (ICLF) systems in relation to ingestive behavior of dairy heifers, a 2 × 2 crossover trial was conducted with two periods and two systems. Eight Girolando (3/4holstein × 1/4 Gyr) heifers were evaluated in pasture of Xaraés palisade grass (Urochloa brizantha 'Xaraes' syn Brachiaria brizantha) managed with intermittent stocking. The ICLF systemhad eucalyptus trees planted in tiers with 65% crown cover. Ingestive behavior parameters were obtained using acoustic data collected with mP3 recorders for 48hours. Statistical analysis was performed using the mixed procedure of SAS, and means were compared using the Tukey-Kramer test at 5% significance. The dry mater intake (DMI), number of daily grazing sessions, and the duration of the grazing sessions did not differ (P<0.05) between systems. A higher (P<0.05) bite rate and total daily bites and lower (P<0.05) bite mass was observed in the ICLF system in relation to ICL. Heifers in shaded pasture change their ingestive behavior in comparison with those in full-sun pasture.(AU)

Com o objetivo de comparar sistemas de integração lavoura-pecuária (ILP) e lavoura-pecuária-floresta (ILPF) em relação ao comportamento ingestivo de novilhas leiteiras, conduziu-se um ensaio em delineamento crossover 2 × 2, com dois períodos e dois sistemas. Oito novilhas Girolando foram mantidas em pastagens de capim-xaraés (Urochloa brizantha 'Xaraes' syn Brachiaria brizantha) manejadas com lotação intermitente. No sistema ILPF, havia renques de eucalipto com 65% de cobertura de copa. O comportamento ingestivo foi avaliado pela análise de áudios coletados com gravadores de Mp3, durante 48 horas. As análises estatísticas foram realizadas utilizando-se Proc mixed SAS. As médias foram comparadas pelo teste Tukey-Kramer, ao nível de 5% de significância. A ingestão de matéria seca (IMS), o número de sessões de pastejo por dia e a duração das sessões de pastejo não diferiram (P<0,05) entre os sistemas. As maiores (P<0,05) médias de taxa de bocado e de número de bocados por dia e a menor (P<0,05) média de massa de bocado foram observadas no ILPF quando comparado ao ILP. Novilhas em pastagem sombreada alteram seu comportamento ingestivo quando comparadas àquelas que são mantidas em pastagem a pleno sol.(AU)

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The objective of this study was to evaluate the feeding and agonistic behavior of Quarter Horses kept in different types of stalls in the semiarid region of Minas Gerais. A completely randomized design with two treatments (two types of stalls) and seven replicates (seven days of evaluation) was used. Four Quarter Horse mares and four stallions were used per treatment. Behavioral observations were made at 10-minute intervals for 24 hours. The stall environment was characterized by the following variables: air temperature, relative humidity, and black globe temperature for subsequent estimation of the wet-bulb globe temperature. Feeding behavior variables included: time spent eating concentrate and time spent eating roughage (hours), bite rate (bites/min), and the number of daily bites (bites/day). Zinc-roofed stalls had higher air temperatures than clay-roofed stalls and the external environment, averaging 28.2, 27.0, and 27.4 ºC, respectively, while relative humidity was significantly lower in the external environment (65.80%). Horses housed in zinc-roofed stalls had longer feeding times (8.32 h) than animals kept in clay-roofed stalls (7.22 h). Approximately 94% of the total feeding time was spent eating roughage and 73% of the time was spent resting and walking, regardless of the covering type. Although environmental variables showed thermal discomfort, the roofing material did not alter the feeding behavior of stabled horses in the semiarid region of Minas Gerais, suggesting an adaptation to the studied conditions. The feeding frequency should be increased to avoid a long resting time.(AU)

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Feeding behavior analysis provides information about the relationships between animals and pastures. Therefore, this review aims to describe some aspects of the feeding behavior profiles of both sheep and goats in grazing systems. The structure of the pasture is a key factor in the feeding behavior of grazing animals. The amount of feed consumed in a given period of time is affected by the number of meals, duration and velocity of swallowing, changes in grazing time, bite rate, bite weight, and quality of ingested forage. The different phenological stages of forage also influence the animals’ strategies to optimize their intake, which consequently changes their behavioral activities. Sheep and goats tend to be more selective than cattle, and young animals are more selective than older animals; this selectivity characteristicis one of the most important aspects to be observed in pasture management. According to the degree of selectivity, the animals will intake forages of higher or lower nutritive quality. In addition, the intensity and distribution of their daily activities (grazing, ruminating, and resting)are influenced by several factors, such as the availability and nutritive value of the pasture, its management, the animal activity in the group, and the predominant climatic conditions of the region.

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Between 40,000-70,000 people die yearly of rabies, an incurable disease. Besides post-bite vaccination, no treatment is available for it. Methods: First, virus dilution for antiviral effects in mice was determined. Then, animals were treated as follows: control (NaCl 250 µL/animal/day); bufotenine (0.63, 1.05 and 2.1 mg in 250 µL of NaCl/animal/day); rabies (10-6,82CVS dilution); and test (10-6,82 CVS dilution and bufotenine, in the above-mentioned doses). Animals were observed daily for 21 days or until the 3rd stage of rabies infection. Twitch-tension and liposome studies were applied to understand the possible interaction of bufotenine with receptors, particularly acetylcholine. Results: Bufotenine was able to increase the survival rate of intracerebrally virus-infected mice from 15 to 40%. Bufotenine did not seem to interfere with the acetylcholine response in the skeletal muscle, indicating that its mechanism of action is not blocking the virus entrance due to nAChR antagonism. By analyzing liposomes, we could observe that bufotenine did not passively penetrates cell membranes, indicating the necessity of complementary structures to cell penetration. Conclusions: Bufotenine is a promising candidate for drug development. After further chemical modification, it might be possible to dissociate minor side effects, increase efficiency, efficacy and pharmacokinetics, yielding a true anti-rabies drug.(AU)

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Background: Rabies is an infectious disease that is important in the “One Health” worldwide with high lethality rate. The etiological agent is a neurotropic virus, genus Lyssavirus, transmitted mainly through the saliva of infected animals. For equines, the bite of hematophagous bats is the main source of infection. Piauí is an important state for equestrian sports and the increase in the number of horses with neurological clinical signs without diagnosis has increased in recent years. In this context, the aim of this study is to report to the scientific community a confirmed case of equine rabies in the Santa Luz county, Southernmost state of Piauí, Brazil. Case: A 3-year-old female non-defined breed horse, was admitted to the Hospital Veterinário da Universidade Federal do Piauí (UFPI/CPCE). The equine had difficulty walking 2 days ago, in the panoramic inspection was restless and disoriented in the paddock. Rectal temperature of 38.2°C, heart rate of 60 bpm, respiratory rate of 40 mpm, congested mucosa and dyspnea were verified. With the progression of the neurological signals, it positioned itself in a lateral decubitus with pedaling movements, hyperesthesia, dysphagia and paralysis of the hindlimbs. The clinical suspicion was rabies and the Agência de Defesa Agropecuária do Piauí (ADAPI) was communicated to euthanize the animal and collect samples for diagnosis in accordance with official standards of the Ministério da Agricultura, Pecuária e Abastecimento (MAPA). At necropsy, there was slight brain hyperemia, with no other significant organ changes. Fragments of the cerebellum, cortex, hippocampus and spinal cord were collected and sent at a temperature of 4°C to perform the Direct Immunofluorescence (DIF) assay. Samples for histopathology were not collected because they do not include assay for confirmatory diagnosis of rabies. The DIF technique with...

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This study evaluated how changing the structure of Brachiaria brizantha cv. Marandu pasture under different forage allowances (FA) of 4, 7, 10 and 13kg DM/100kg BW (body weight) affected animal behavior over a two-year evaluation period. The experiment was conducted as a randomized block design with three replications (paddock). Sward height, total forage, and stem mass were lower for pastures managed with lower FA. Lower leaf mass was observed for lower FA in the second year. In hand-plucked samples, leaf and stem percentages remained unchanged in the morning but leaf percentage increased while stems decreased in the afternoon. Permanence time decreased linearly with increasing FA. In turn, a quadratic effect was observed for displacement rate. The bite rate was similar among different FAs. The results demonstrate that FA varying between 7 and 10kg DM/100kg BW are more suitable to balance the amounts of leaves and stems in the sward. The studied FA levels do not limit forage availability. Permanence time decreases and displacement rate increases as FA increases.(AU)

O objetivo foi avaliar como mudanças na estrutura de pastos de Brachiaria brizantha cv. Marandu, sob diferentes ofertas de forragem (OF) de 4, 7, 10 e 13kg MS/100kg PC, afetam o comportamento animal durante um período de avaliação de dois anos. O delineamento utilizado foi em blocos ao acaso, com três repetições (piquetes). A altura do dossel, a massa de forragem total e de colmos foram menores em pastos manejados com menores OF. A menor massa de folhas foi observada na menor OF no segundo ano. Nas amostras de pastejo simulado, as porcentagens de folhas e colmos não diferiram pela manhã, mas a porcentagem de folhas aumentou, enquanto a de colmos diminuiu à tarde. O tempo de permanência dos animais diminuiu linearmente com o aumento das OF. Efeito quadrático foi observado para taxa de deslocamento. A taxa de bocados foi similar entre as OF. Os resultados demonstram que variar as OF entre 7 e 10kg MS/100kg PC é mais adequado para balancear as quantidades de folhas e colmos no dossel forrageiro. Os níveis de OF estudados não limitam a forragem disponível. O tempo de permanência diminuí e a taxa de deslocamento aumenta com o aumento das OF.(AU)

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This studyaimed to assess the influence of three pre-grazing heights of Massai grass on the ingestive behavior of sheep under rotational stocking. Eighteen Dorper x nondescript crossbred sheep were used under rotational stocking on Massai grass at pre-grazing heights. The animal stocking was estimated to ensure a reduction of approximately 50% of the initial height. Behavior assessments were performed from 6 to 18 h at the entrance and exit of animals from paddocks. The longest activity was grazing, followed by rumination and other activities, and the period from 6 to 10 h showed the longest grazing.In the other periods, the animals in the 35-cm treatment grazed less when compared to those ofthe other treatments. Rumination in all treatments was more significant in the period from 14 to 18 h, but the animals in the 45-cm treatment spent more time doing this activity, which gave them a higher time of rumination of the food bolus, as well as ruminating chews. The bite rate was higher for the 25-cm treatment, followed by the 45 and 35-cm treatments, respectively.

O objetivo foi avaliar a influência de três alturas pré-pastejo do capim Massai sobre o comportamento ingestivo de ovinos sob lotação rotativa. Foram utilizados 18 ovinos mestiços Dorper x sem padrão racial definido (SPRD) sob lotação rotativa em capim Massai nas alturas pré-pastejo de 45, 35 e 25 cm. A lotação animal foi estimada para garantir a redução de aproximadamente 50% da altura inicial. As avaliações de comportamento foram feitas das 6 às 18 h na entrada e na saída dos animais dos piquetes. A maior atividade de forma geral realizada foi a de pastejo, seguida de ruminação e outras atividades, sendo o período de 6 às 10 h o que apresentou maior atividade de pastejo. Nos demais períodos, os animais no tratamento com 35 cm pastejaram menos que os animais dos outros tratamentos. A ruminação, em todos os tratamentos, foi mais significativa no período das 14 às 18 h, mas os animais no tratamento com 45 cm foram os que passaram maior tempo realizando esta atividade. Os animais no tratamento com 45 cm apresentaram maior tempo de ruminação do bolo alimentar e maior número de mastigações merícicas. A taxa de bocados foi superior para o tratamento com 25 cm, seguido do com 45 e 35 cm respectivamente.

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This study aimed to evaluate the performance and ingestive behavior of growing goats grazing on Tanzania guinea grass and fed diets containing 40% carnauba or tucum fruits. Twenty-one male castrated goats were distributed into three groups, one exclusively on pasture and the other two on pasture and fed diet supplemented at the level of 1.5% body weight (BW) in a completely randomized design. The intake of the supplements was obtained by difference between the amount supplied and the leftovers, with weighing performed every seven days, while pasture intake was determined using titanium dioxide (TiO2) as external indicator. Ingestive behavior was evaluated for three days. The supplement containing carnauba fruit resulted in a greater intake of neutral detergent fiber (0.137 kg NDF/day), with a reduction of 8.61% in the pasture dry matter (DM) intake of goats. Associated with the intake of pasture nutrients, the tucum fruit diet met the protein (0.103 kg CP/day) and energetic (0.547 kg TDN/day) requirements of goats with intake set at 0.124 kg CP/day and 0.572 kg TDN/day, with higher weight gain (0.111 kg/day) and larger loin eye area (12.76 cm2). The supplementation with fruits influenced the grazing behavior of goats, increasing the idle time by 1 h in relation to animals not supplemented. The supplementation of growing goats grazing on Tanzania guinea grass pasture with a diet containing 40% tucum fruit, in the proportion of 1.5% BW, did not meet the nutritional requirements for gain of 150 g/day; however, it met requirements for maintenance and average gain of 111 g/day. Energy supplementation reduces the grazing time of goats; thus, it is necessary to consider the level and formulation of supplements, with the possibility of increasing the stocking rate and productivity per unit area.(AU)

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A leishmaniose é uma doença endêmica sendo comum em regiões pobres de países em desenvolvimento. Essa parasitose é causada por protozoários do gênero Leishmania, pertencentes à família Trypanosomatidae e responsável pela segunda maior taxa de mortalidade mundial. Dentre os hospedeiros vertebrados há uma grande variedade de mamíferos, e a transmissão ocorre principalmente por meio da picada de fêmeas de flebotomíneos do gênero Lutzomyia, principais vetores no Brasil. Nos hospedeiros mamíferos a forma amastigota intracelular coloniza principalmente os macrófagos, os quais atuam na eliminação do patógeno. Contudo, para se manter vivo, o parasita evita os mecanismos de defesa, os quais podem ser regulados por processos epigenéticos dos macrófagos. Dentre esses, destacam-se os RNAs longos não-codificadores (lncRNA), que apresentam diversas funções incluindo o controle da expressão de genes alvos próximos ou distantes. Considerando a capacidade regulatória deste protozoário, identificar a relação na expressão de lncRNAs e seus possíveis alvos, em macrófagos infectados com Leishmania, é importante para o entendimento do papel dos processos epigenéticos no diálogo parasita-hospedeiro, na leishmaniose.

Leishmaniasis an endemic disease common in poor regions of developing countries, caused by protozoa of the genus Leishmania, belonging to the Trypanosomatidae family, it is the parasitic disease responsible for the second highest mortality rate worldwide. Among the vertebrate hosts there is a wide variety of mammals, and transmission occurs mainly by the bite of female sandflies of the genus Lutzomyia, the most important vector in Brazil. In mammalian hosts, the intracellular amastigote form colonizes mainly macrophages, which try to eliminate the pathogen. However, to stay alive, the parasite avoids the macrophage defense mechanisms, which can be regulated by epigenetic processes. Among these, long non-coding RNAs (lncRNA) several roles, including controlling the paly expression of nearby or distant target genes. Considering the lncRNA capacity for gene regulation, understanding the relationship of lncRNAs and their possible targets, in macrophages infected with Leishmania, is important in to understand the role of epigenetic processes in the host-parasite relationship Leishmaniasis.

Resumo

Objetivou-se avaliar o desempenho e o comportamento de novilhas de primeira cria e a estrutura de uma pastagem natural manejada em pastoreio rotativo com intervalos de descanso baseados em parâmetros ecofisiológicos de grupos de gramíneas nativas do bioma Pampa. O estudo durou 174 dias durante a primavera/verão de 2019/2020. A área experimental foi dividida em dois tratamentos baseados nos intervalos de descanso da pastagem determinados pelo acúmulo térmico de 375 e 750 graus dia. As variáveis estruturais do pasto, % de Folhas, % de MM e % de Outros, apresentaram interação tratamento x período. A % de MM foi semelhante entre os tratamentos durante a primavera com média de 49%. No verão, o tratamento 375 GD apresentou 72,3% de MM e o 750 GD apresentou 50% de MM. A % de Outros contribuiu com menos de 3% na massa de forragem. A % de folhas no período de primavera foi semelhante entre os tratamentos com média de 53%. No verão, observou-se diferença entre os tratamentos com o tratamento 750 GD apresentando 49% de folhas e o tratamento 375 GD 35% de folhas. Dentre as variáveis relacionadas ao desempenho animal, Lotação instantânea (Linst) (kg.ha-1) e GMD (kg.dia-1) não diferiram para tratamento e estação, apresentando medias de 3143 kg ha-1 e 0,285 kg/dia respectivamente. O GPA/dia também não apresentou diferença entre tratamentos e estações, obtendo uma média de 0,59 kg de PC.dia.-1ha-1. A variável Lotmed diferiu entre os tratamentos, onde o tratamento 375 GD apresentou um valor de 912 em kg.ha-1 e o tratamento 750 GD, 719 kg.ha-1. A Oferta de folhas foi diferente entre os tratamentos e entre os períodos. Para o tratamento 375 GD os valores foram superiores apresentando uma oferta de 15%. Dentre as variáveis relacionadas à qualidade da forragem nenhuma apresentou diferença entre os tratamentos. Quando realizada a comparação entre períodos, apenas PB diferiu, com valores de 8,5, 6,3 e 5,6 para os períodos 1, 2 e 3 respectivamente. Das variáveis de comportamento ingestivo apenas a taxa de bocado apresentou interação tratamento e período. No primeiro período, o tratamento 375 apresentou uma taxa de bocado média de 17 bocados/minuto enquanto o tratamento 750 apresentou uma taxa de 46 bocados/minuto. Quanto às estações alimentares, os animais do tratamento 375 percorreram 1,9 estações/ minuto a mais do que os animais do tratamento 750. Quanto aos períodos, os animais percorreram mais estações no primeiro e segundo período do que no terceiro período. Em se tratando dos passos entre estações, no primeiro e terceiro períodos, os animais percorreram uma média de 1,45 passos entre estações, enquanto no segundo período foram 2,02 passos entre estações . O manejo proporcionou valores satisfatórios de desempenho individual e de produtividade, com valores superiores para o tratamento 375 GD. Os diferentes intervalos de pastejo baseados na soma térmica de 375 graus-dia e 750 graus-dia influenciaram o comportamento ingestivo das novilhas.

This study aimed to evaluate the performance and behavior of first-calf heifers and the structure of a natural pasture under the rotational grazing method with rest intervals based on ecophysiological parameters of the main groups of native grasses of the Pampa biome. This experiment lasted 174 days during the spring/summer of 2019/2020 and was conducted at the Federal University of Santa Maria. The experimental area was divided into two treatments based on the rest interval of the pasture which were determined by the thermal accumulation of 375 and 750 degrees day, favoring grass species from different functional groups. Among the pasture structural variables, % of Leaves, % of MM and % of Others showed treatment x period interaction. The % MM was similar between treatments during spring with a mean of 49%. In the summer, the 375 GD treatment presented 72.3% of MM and the 750 GD presented 50% of MM. The % of Others contributed less than 3% of the forage mass. The % of leaves in the spring period was similar between treatments with an average of 53%. In the summer, there was a difference between the treatments with the treatment 750 GD presenting 49% of leaves and the treatment 375 GD 35% of leaves. Among the variables related to animal performance, Instantaneous stocking (Linst) (kg.ha-1) and ADG (kg.ha-1) did not differ for treatment and season, with averages of 3143 kg ha-1 and 0.285 kg/day, respectively. GPA/day also showed no difference between treatments and seasons, obtaining an average of 0.59 kg of BW.ha-1. The variable Lotmed differed between treatments, where the treatment 375 GD presented a value of 912 in kg.ha-1 and the treatment 750 GD 719 kg.ha- 1. Leaves allowance was different between treatments and between periods. For the 375 GD treatment, the values were higher, presenting an allowance of 15%. Among the variables related to forage quality, none showed a difference between treatments. When comparing periods, only crude protein differed, with values of 8.5, 6.3 and 5.6 for periods 1, 2 and 3 respectively. Of the ingestive behavior variables, only the bite rate showed interaction between treatment and period. In the first period, treatment 375 had an average bite rate of 17 bites/minute while treatment 750 had an average bite rate of 46 bites/minute. As for the feeding stations, the animals of treatment 375 traveled 1.9 stations/minute more than the animals of the treatment 750. As for the periods, the animals traveled more stations in the first and second period than in the third period. In terms of steps between stations, in the first and third periods, the animals walked an average of 1.45 steps between stations, while in the second period there were 2.02 steps between stations. The management provided satisfactory values.of individual performance and productivity, with higher values for the 375 GD treatment. The different grazing intervals based on the thermal sum of 375 degree-days and 750 degree-days influenced the ingestive behavior of heifers.

Resumo

A anestesia geral inalatória é recomendada para manutenção anestésica em tartarugas-marinhas; contudo, questiona-se a influência do oxigênio puro (100% de fração inspirada de oxigênio) nas prolongadas recuperações anestésicas comumente reportadas. Este estudo objetivou comparar o tempo de recuperação de tartarugas- verdes (Chelonia mydas) anestesiadas com sevofluorano diluído em oxigênio puro (FI100) ou ar ambiente (FI21), e avaliar o impacto cardiorrespiratório e ácido-base produzido por ambas as frações. Em um design aleatorizado, encoberto e cruzado, onze indivíduos foram anestesiados (FI100 ou FI21; uma semana de intervalo). Após propofol intravenoso (5 mg/kg) e intubação endotraqueal, foram mecanicamente ventilados com sevofluorano por 90min. Foram analisadas a frequência cardíaca (FC), a pressão parcial de CO2 expirado (PETCO2) e a fração expirada de sevofluorano (FESEVO) a cada 10min. A oximetria de pulso (SpO2) foi obtida a cada 30min. A FESEVO foi mantida em 3,5%. Aos 90min, o sevofluorano foi descontinuado e registrou-se os tempos de bicar o abre-bocas, primeiro movimento muscular, primeira tentativa de extubação e extubação. Gases sanguíneos venosos foram analisados 10min antes da indução (MBa), 90min do transanestésico (MAn) e após extubação (MExt). O único tempo de recuperação anestésica distinto entre grupos foi bicar o abre-bocas (FI100: 51 [39 58] min e FI21: 44 [31 53] min; p = 0,03). A SpO2 foi maior em FI100 do que FI21 em todos os momentos avaliados (p < 0,01). A FC e o PETCO2 não diferiram entre grupos, porém ambos reduziram ao longo do tempo (p < 0,05). Os gases sanguíneos não diferiram entre os grupos em nenhum dos momentos. O pH aumentou (p < 0,001) e o PvCO2 reduziu (p < 0,0001) em MAn e MExt em relação a MBa em ambos os grupos. O oxigênio puro não influencia o tempo de recuperação anestésica e não impacta em parâmetros cardiorrespiratórios em relação ao ar ambiente em tartarugas- verdes anestesiadas com sevofluorano.

The inhalation anesthesia is recommended for anesthetic maintenance in sea turtles; however, the role of pure oxygen (100% fraction of inspired oxygen) on the prolonged anesthetic recoveries commonly reported in sea turtle anesthesia has been questioned. This study aimed to compare recovery times in sevoflurane-anesthetized green turtles (Chelonia mydas) receiving pure oxygen (FI100) or room air (FI21), and to evaluate the impact of both fractions on cardiorespiratory and blood gas variables. In a randomized, blinded and cross-over design, eleven turtles were anesthetized (FI100 or FI21; one-week interval). Following intravenous propofol (5 mg/kg) and endotracheal intubation, animals were mechanically ventilated with sevoflurane for 90min. Heart rate (HR), partial pressure of expired CO2 (PETCO2) and expired sevoflurane fractions (FESEVO) were analyzed every 10min, and pulse oximetry (SpO2) every 30min. The FESEVO was set at 3.5%. At 90min of anesthesia, sevoflurane delivery ceased and times to beak the bite block, first muscle movement, first attempt to extubate and extubation were registered. Venous blood gas analysis was performed at 10min before anesthesia induction (MBa), 90min during anesthesia (MAn) and immediately following extubation (MExt). Time to beak the bite block was the only recovery variable different between groups (FI100: 52 ± 14.57 min and FI21: 44.64 ± 14.42 min; p = 0.03). The SpO2 was higher in FI100 than in FI21 at all timepoints of analysis (p < 0.01). The PETCO2 and HR did not vary between groups, though both reduced over time (p < 0.05). Blood gases were not different between groups. The pH increased (p < 0.001) and PvCO2 reduced (p < 0.0001) in MAn and MExt compared to MBa in both groups. Pure oxygen does not influence time to recovery from anesthesia nor does it impair cardiorrespiratory variables in comparison to room air in sevoflurane- anesthetized green turtles.

Resumo

Essa tese tem como objetivo avaliar a efetividade do corte de amostras na altura de resíduo para estimar o valor nutritivo de dietas compostas de capim-marandu e amenodim forrageiro pastejados até três alturas de resíduo; e determinar a densidade de desfolhação que favorece o consumo de forragem de maior qualidade, aumentando a eficiência de utilização de nitrogênio aparente. O experimento foi conduzido na Universidade Federal de Lavras, MG, Brasil por dois anos consecutivos. A área foi dividida em 12 unidades experimentais (piquetes) com três intensidades de desfolhação (severa, moderada e leve). A área experimental era consituída de capim-marandu (Urochloa brizantha cv. Marandu) e amendoim forrageiro (Arachis pintoi cv. Mandobi). Para comparar o valor nutritivo de amostras coletadas por pastejo simulado e corte na altura do resíduo, foram testadas duas hipóteses: H0: 0 = 0 e H0: 1 = 1. Também foi realizada uma análise de correlação de Pearson para testar se a composição química de cada metodologia é correlacionada. A hipótese H0: 0 = 0 foi aceita para as concentrações de proteína bruta (PB), fibra em detergente neutro livre de cinzas e proteína (FDN) e matéria orgânica (MO) de capim-marandu e amendoim forrageiro. A hipótese H0: 1 = 1 foi rejeitada para as concentrações de PB, FDN e MO de capim-marandu, e para as concentrações de PB e MO de amendoim forrageiro (P<0.01), mas não para concetração de FDN do amendoim forrageiro (P=0.24). O coeficiente de correlação de Pearson não foi significativo para nenhum componente químico avaliado (P>0.05). Intensidade de desfolhação (ID), estação (E) e a interação entre intensidade de desfolhação e estação (ID×E) foram consideradas como efeito fixo, ano e repetição foram considerados como efeito aleatório. A desfolhação leve apresentou maior oferta de forragem e menor taxa de lotação que as outras intensidades (6.3 kg MS/kg PV e 1.3 UA/ha). Tempo de pastejo não diferiu no primeiro dia de ocupação (390 min; P=0.15) e nem no último dia (440 min; P=0.20). Durante o último dia, a desfolhação leve apresentou 70% maior taxa de ingestão (33,0 g MS/min) que a média dos outros tratamentos, relacionada com a maior taxa de bocados (38,0 bocados/min) e peso do bocado (0,9 g MS/bocado). O consumo total de forragem e de gramínea (CMS; %PV) foram maiores para desfolhações moderada e leve, mas o consumo de leguminosa foi menor para desfolhações moderada e severa. A eficiência de síntese de proteína microbiana (ESPM) foi 100 g de PM/kg MOD maior durante o verão comparado com a primavera, mas não variou de acordo com a ID (P=0.80). O corte de amostras de pastos mistos na altura do resíduo não é uma metodologia eficiente para avaliar o valor nutritivo de dietas consumidas porque não é capaz de incorporar o hábito de seleção e as heterogeneidades espaciais e morfológicas. A desfolhação moderada aumenta a taxa de lotação sem reduzir o CMS.

This dissertation aims to evaluate the effectiveness of clipping samples at stubble height to estimate the nutritive value of diets composed by marandu palisade grass and pintoi peanut grazed at three stubble heights; and to determine a defoliation intensity that would favor forage intake with more quality, increasing the apparent efficiency of nitrogen utilization. The trial was conducted at the Universidade Federal de Lavras, MG, Brazil for two consecutive years. The area was divided into 12 experimental units (paddocks) with three defoliation intensities (severe, moderate and light). The experimental area was constituted by marandu palisade grass (Urochloa brizantha cv. Marandu) and pintoi peanut (Arachis pintoi cv. Mandobi). In order to compare the nutritive value of samples from hand-plucking and clipping at stubble height, two hypotheses were tested: H0: 0 = 0 and H0: 1 = 1. Pearsons correlation analysis was performed to test if chemical composition of each methodology were correlated. The hypothesis H0: 0 = 0 was accepted for crude protein (CP), ash and protein-free neutral detergent fiber (NDF), and organic matter (OM) concentrations for marandu palisade grass and pintoi peanut. Hypothesis H0: 1 = 1 was rejected for CP, NDF, and OM concentrations for marandu palisade grass and for CP and OM of pintoi peanut (P<0.01), but not for NDF concentration of pintoi peanut (P = 0.24). The averages for CP, NDF, and OM for marandu palisade grass by hand-plucking were 7.9, 74.5, and 91.4 g/100 g DM and by clipping were 7.7, 68.7, and 90.7 g/100 g DM. For pintoi peanut the averages for CP, NDF, and OM by hand-plucking were 15.6, 63.5, and 92.0 g/100 g DM and by clipping were 15.9, 49.3, and 90.8 g/100 g DM. The Pearsons correlation coefficient was not significant for any chemical compound evaluated regardless the species; thus, the methodologies were not correlated (P>0.05). Defoliation intensity (DI), season (S) and the interaction between the two (DI×S) were considered fixed effects, year and replicate were considered random effects. Light defoliation showed greater forage allowance and lower stocking rate than the other intensities (6.3 kg DM/kg LW and 1.3 AU/ha). Grazing time did not differ in the first (390 min; P=0.15) or the last occupation day (440 min; P=0.20). During the last day, light defoliation showed 70% greater intake rate (33.2 g DM/min) than the average of the other treatments, related to greater biting rate (38.0 bites/min) and bite weight (0.9 g DM/bite). Grass and total dry matter intake (DMI; %LW) were greater for moderate and light defoliations, but legume intake was lower for severe and moderate defoliation. The efficiency of microbial synthesis (EMS) was 100 g of microbial protein/kg DOM greater during summer compared to spring but did not vary according to DI (P=0.80). Clipping mixed pasture at stubble height is not an efficient methodology to evaluate the nutritive value of the diet consumed because it is not capable of incorporating grazing selection, spatial and morphological heterogeneity. Moderate defoliation increases SR without reducing DMI.

Resumo

The objective of this study was to evaluate the forage-intake process of goats feeding on Massai grass pastures with different heights (40, 50, 60, and 70 cm). The experimental design was completely randomized, with treatments corresponding to four sward heights with two replicates over time and space. Collected data were related to the forage-intake process and the chemical and morphological composition of the pasture. Grazing trials (45 min) were performed with four Anglo-Nubian crossbred goats. Total forage mass intake, bite mass, and intake rate were expressed in relation to animal weight. Pasture density, forage mass, and leaf blade increased as forage height increased. The chemical composition of forage at the evaluated heights was similar, except for reduced crude protein content at 70-cm height. Bite rate, intake rate, and time per bite had a quadratic relationship with increasing sward height. The greatest intake rate was observed at 54.7 cm of height, with 0.136 g DM min-1 kg-1 LW. Bite rate exhibited a linear and positive correlation with increase in intake. At the 50-cm height, goats harvested a mass of 3.65 g DM bite-1 kg-1 LW, when they performed 34.5 bites per minute. Adult goats had a greater forage intake on 50-cm high Massai grass pastures because they could obtain a greater bite mass in a shorter time per bite.

Objetivou-se avaliar os processos de ingestão de forragem por caprinos em pastagem com capim-Massai manejado sob diferentes alturas (40, 50, 60 e 70 cm). O delineamento adotado foi o inteiramente casualizado. Os tratamentos corresponderam a quatro alturas do dossel com duas repetições no tempo e no espaço. Os dados coletados foram relacionados aos processos de ingestão de forragem e composição química e morfológica do pasto. Foram realizados testes de pastejo de 45 minutos com quatro cabras mestiças da raça Anglonubiana. A massa de forragem total consumida, massa de bocados e a taxa de ingestão foram expressos em relação ao peso dos animais. Com o incremento da altura da forragem houve aumento na densidade do pasto, massa de forragem e lâmina foliar. A composição química da forragem nas alturas avaliadas foi semelhante, com exceção da redução do teor de proteína bruta aos 70 cm. A taxa de bocado, taxa de ingestão e tempo por bocado apresentou relação quadrática com o aumento da altura. A maior taxa de ingestão foi observada aos 54,7 cm de altura, com 0,136 g MS min-1 kg-1 de PC. A massa de bocado apresentou relação linear e positiva com o aumento da altura. Aos 50 cm as cabras colheram uma massa de 3,65 g MS bocado-1 kg-1 PC, quando realizavam 34,5 bocados por minuto. No pasto de capim-massai aos 50 cm ocorre maior consumo de forragem por cabras adultas, pois os animais conseguem obter uma massa maior do bocado em menor tempo por bocado.

Resumo

Em sistemas integrados de produção agropecuária (SIPA) onde há o arranjo de pastagens e árvores, o efeito do sombreamento das árvores causa alterações estruturais no pasto que podem influenciar o comportamento ingestivo dos animais em pastejo. Este trabalho teve como objetivo estudar os efeitos do sombreamento em pastagem de grama missioneira-gigante (Axonopus catharinensis Valls. cv SCS 315 Catarina Gigante) em comparação ao pleno sol, em duas alturas pré-pastejo, e suas relações com o comportamento ingestivo de ovinos. Foram utilizados 8 piquetes de 20 m², distribuídos em pleno sol ou ambiente sombreado (sombrites com 50% de interceptação luminosa), e duas alturas pré-pastejo (25 cm e 35 cm), com rebaixamento em 40% da altura inicial. Foram utilizadas quatro ovelhas da raça Lacaune previamente adaptadas. Os testes de pastejo eram feitos pela manhã e tarde. A taxa de ingestão dos animais foi aferida pela técnica de dupla pesagem, com correção para perdas insensíveis de peso. Foram determinadas a taxa e a massa de bocados. Dois cortes de forragem foram realizados por piquete, ambos em 50% da altura do dossel e ao nível do solo, utilizando quadros de 0,25 m² para determinação da massa de forragem (MF). A partir do estrato superior apenas obteve-se a densidade de forragem e análises da composição química. A densidade populacional de perfilhos (DPP) foi determinada em quatro quadros e 40 perfilhos estendidos marcados foram medidos antes e após as sessões de pastejo. Os dados foram analisados através de modelos lineares mistos no ambiente estatístico R. A MF foi semelhante entre sol e sombra e superior em 35 cm comparado a 25 cm, sem alterar a densidade de forragem entre todos os tratamentos. A DPP reduziu em 38% na sombra comparada ao pleno sol e a relação folha: colmo manteve se semelhante. A fibra em detergente neutro (FDN) aumentou em função da altura e do ambiente sombreado, enquanto a fibra em detergente ácido (FDA) e a proteína bruta (PB) mantiveram-se semelhantes entre tratamentos. A taxa de ingestão, a massa de bocados e a profundidade de bocados foram semelhantes entre alturas e condições luminosas, mas o tempo por bocado foi maior no sol em comparação ao ambiente sombreado. A densidade de forragem do estrato pastejado não diferiu em função da luminosidade e variações na altura do pasto não modificaram a profundidade de bocados e a densidade de forragem. A taxa de ingestão de ovinos em pasto de missioneira-gigante não se modifica com a redução da luminosidade e entre as alturas de pré-pastejo de 25 e 35 cm.

In an integrated crop-livestock system (ICLS) combining trees and pastures, shading effect caused by trees may modify sward structure and ingestive behavior of grazing animals. The aim of this study was to assess the effects of shading on the ingestive behavior of sheep grazing missioneira-gigante grass (Axonopus catharinensis Valls. SCS 315 Catarina Gigante) compared with full sun environment, at two pre-grazing canopy target heights. Eight paddocks of 20m² were used in sun or shade (based on shade clothes with 50% LI), at pre-grazing heights of 25 cm and 35 cm, managed for 40% of grazing intensity. Four previously adapted Lacaune sheep were used. The grazing tests were performed in the morning and afternoon, and short-term intake rate (STIR) was measured by double-weighing technique, with correction for insensive weight losses. Bite rate and bite mass were determined. Two forage cuttings were made by paddock, each starting at 50% of the canopy height and then until ground level in frames of 0.250 m² to obtain herbage mass (HM), herbage bulk density (HBD) and chemical composition. Tiller density were counted in four frames, and 40 marked extended tillers were measured before and after grazing sessions. Data were analysed using linear mixed models in R statistical environment. The HM was similar between sun and shade and higher at 35 cm compared with 25 cm, but HBD remained unchanged. The tiler density dropped by 38% in shade, but leaf: stem ratio remained similar between treatments. The NDF content increased as a function of sward height and shade environment, but the ADF and CP content did not change between treatments. The STIR, bite mass and bite depth did not change between pre-grazing canopy target Heights and light conditions, but time per bite was greater in full sun environment compared with shade. Sheep grazing missioneira-gigante grass did not change STIR in shade compared with full sun environment, regardless the pre-grazing canopy target height.