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1.
Acta sci., Anim. sci ; 45: e59494, 2023. tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1428410

Resumo

To gain insights into the forage morphological and anatomical characteristics in a silvopastoral system (SPS) with Bolsa de Pastor (Zeyheria tuberculosa) and palisadegrass 'Marandu' (Urochloa brizantha) monoculture (MONO). The SPS was established through natural regeneration of the tree species. Treatments were a SPS and MONO distributed in a completely randomized design with six replicates and repeated measures were the harvest periods. Response variables were morpho-physiological and anatomical characteristicss: green: dead material ratio, leaf blade: stem+sheath ratio, leaf area index, chlorophyll and carotenoid concentrations, proportions of non-lignified and achlorophyllous areas, lignified areas in stems, proportions of non-lignified and achlorophyllous areas, lignified and chlorophyllous areas in leaves, as well as cell length in longitudinal section of stem. Morpho-physiological patterns were altered (p < 0.05) under natural shading conditions due to higher photosynthetic efficiency in the SPS. There was no effect (p > 0.05) of the systems on anatomical patterns, proportions of non-lignified and achlorophyllous, lignified and chlorophyllous tissues, these proportions were influenced only by the periods of the year, both for stems and leaves. Cells of the internodes of the grasses of the studied systems had the same length. The SPS alters morpho-physiological characteristics of palisadegrass and increases the concentration of chlorophyll a and b.(AU)


Assuntos
Fenômenos Fisiológicos Vegetais , Poaceae/anatomia & histologia , Pastagens
2.
Acta sci., Anim. sci ; 45: e59307, 2023. tab, ilus, graf
Artigo em Inglês | VETINDEX | ID: biblio-1428317

Resumo

The objective was to assess the physiological and behavioral variables of pasture-raised Holstein heifers on the basis of their coat color. Eight heifers were used, four with black coat, and four with white coat. In the morning and afternoon periods, their physiological variables were measured, namely respiratory rate (RR, mov min. -1), rectal temperature (TR, ºC), and coat surface temperature (TS, ºC). The behavior analysis considered the site (sun or shade), position (standing or lying down), and activities (idleness, rumination, grazing, and others). The data of the physiological variables were assessed through analysis of variance, and significance, through Tukey's test at 5%, while behavioral data were assessed using the Chi-squared test (SAS Software). There was a difference for all of the heifers' physiological variables as a function of coat color (p < 0.0001) and period (p < 0.0001), with black ones showing greater results than white ones as to all physiological variables in the afternoon period (p < 0.0001). Grazing behavior is reduced during the hottest hours of the day. We conclude that solar radiation changes the physiological variables and grazing behavior of pasture-raised Holstein heifers.(AU)


Assuntos
Animais , Feminino , Bovinos/fisiologia , Pastagens , Radiação Solar , Comportamento Animal , Modalidades Fisiológicas
3.
Rev. Ciênc. Agrovet. (Online) ; 22(2): 207-217, mai. 2023. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1444995

Resumo

O estudo de aspectos químicos e bioquímicos associados ao desenvolvimento das diferentes partesdas plantas permite a observação e o entendimento de uma série de reações que levam à produção de fitomassa e grãos pela cultura de milho. Assim, objetivou-se estudar a diferença na eficiência de uso do nitrogênio nas raízes e parte aérea em dois genótipos de milho, na fase inicial de crescimento das plantas e avaliar as respostas bioquímico-fisiológicas desses órgãos quando as plantas são submetidas a distintas doses de N em condições hidropônicas. O experimento foi realizado em casa de vegetação, em solução nutritiva por20 dias, com dois genótipos (AS1522 e AS1596) submetidos a quatro concentrações de N (zero; 112; 224 e 448 mg dm-3). O delineamento utilizado foi em inteiramente casualizado com trêsrepetições. Houve diferença entre os genótipos estudados para as variáveis biométricas, massa de matéria seca, acúmulo de N e aminoácidos livres totais na parte aérea das plantas. Na raiz, a atividade da redutase do nitrato foi a variável que diferenciou a eficiência no uso do nitrogênio entre os genótipos. O genótipo AS1596 é mais eficiente no uso do nitrogênio.(AU)


The study of chemical and biochemical aspects associated with the development of different plant parts enables the assessment of a series of reactions leading to the production of biomass and grain culture. Thus, the objective of was to study the difference in nitrogen efficiency in roots and shoots of two corn genotypes in the initial stages of plants growth, and evaluate the biochemical and physiological responses of these organs, when plants are subjected to different doses of N, under hydroponic conditions. The experiment was conducted in a greenhouse in nutrient solution for 20 days, with two genotypes(AS1522 and AS1596) subjected to four N concentrations (zero, 112, 224 and 448 mg dm-3). Completely randomized desing with three replications das apply. The major differences among genotypes for biometric variables, dry matter, Nac cumulation and free amino acids were observed in the shoots. At root, the activity of nitrate reductase activity was the variable that stood out and provided the largest differences between genotypes. The genotype AS1596 is more efficient in N utilization.(AU)


Assuntos
Zea mays/fisiologia , Fenômenos Fisiológicos , Nitrogênio/administração & dosagem
4.
Rev. Ciênc. Agrovet. (Online) ; 22(3): 463-469, ago. 2023. ilus, tab
Artigo em Português | VETINDEX | ID: biblio-1451577

Resumo

As poedeiras criadas em sistema degaiolas tem seu bem-estar afetado devido ao menor espaço disponível para elas, o que vai de encontro da crescente pressão por grande parte de consumidores preocupados com as condições em que essas aves são criadas. A consequência dessa menor densidade de alojamento sobre a produtividade, e a qualidade de vida da ave e dos ovos por elas produzidos deve ser avaliada. O objetivo desse estudo é avaliar a produção, qualidade de ovos, e bem-estar de galinhas poedeiras criadas em diferentes densidades de alojamentos em gaiolas. Às 28 semanas de idade, foram distribuídas, em delineamento inteiramente casualizado, 120 poedeiras leves da linhagem Novogen White, após debicagem, em 24 gaiolas com dimensões de 45 cm x 50cm, em três diferentes densidades de alojamento: 562,5 cm² /ave (quatro aves/gaiola), 450 cm² /ave (cinco aves/gaiola) e 375 cm² /ave(seis aves/gaiola), com 8 repetições cada. As dietas experimentais foram isoproteicas e isoenergéticas, formuladas à base de milho e farelo de soja. O período experimental será compreendido por seis ciclos de 28 dias cada. As variáveis analisadas foram: peso do ovo, índice de gema, unidade Haugh, pigmentação da gema, porcentagem dos componentes dos ovos e espessura de casca (em milímetros). Quando as aves atingiram 44 semanas de idade, foi realizada a medição do escore de penas. Foram avaliadas 40 galinhaspor tratamento, em quatro regiões: peito, dorso, asas e posterior. Essa análise consiste emcategorizar as aves de acordo com três diferentes escores, de acordo com o tamanho da área de ausência de penas em cada região. Espera-se que a redução da densidade de alojamento das galinhas nas gaiolas propicie maior produção com melhor qualidade dos ovos, promovendo também melhor bem-estar das aves.(AU)


The well-beingof laying hens raised in cages is affected due to the smaller space available for them,which is in line with the growing pressure from a large number of consumers concerned about the conditions in which these birds are raised.The consequence of thislower housing density on productivity and the quality of life of the bird andthe eggs produced by them must be evaluated. The aim of this study is to evaluate the production, egg quality, and welfare of laying hens reared in different housing densities in cages. At 28 weeks of age, 120 light Novogen White laying hens were distributed, after beak trimming, in24 cages measuring 45 cm x 50 cm, in three different housing densities: 562.5 cm²/bird (four birds/cage), 450 cm²/bird (five birds/cage) and 375 cm²/bird (six birds/cage), with 8 repetitions each. The experimental diets were isoproteic and isoenergetic, based on corn and soybean meal. The trial period will comprise six cycles of 28 days each. The variables analyzed were: egg weight, yolk index, Haugh unit, yolk pigmentation, percentage of egg components and shell thickness (in millimeters). When the birds reached 44 weeks of age, the feather score was measured. Forty chickens per treatment were evaluated in four regions: chest, back, wings and hindquarters. This analysis consists of categorizing the birds according to three different scores, according to thesize of the area without feathers in each region. It is expected that the reduction in the hen housing density in the cages will lead to higher production with better egg quality, also promoting better hen welfare.(AU)


Assuntos
Animais , Feminino , Estresse Fisiológico/fisiologia , Bem-Estar do Animal , Galinhas/fisiologia , Ovos/análise
5.
Acta sci. vet. (Impr.) ; 51: Pub. 1914, 2023. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1443882

Resumo

Background: Canine hypercortisolism (HC) is the most prevalent endocrinopathy in dogs in southern Brazil. The prognosis depends on several factors including the general health status, owners´ commitment, and the development of disease complications and comorbidities occurrence, such as cardiovascular complications including mitral valve disease (MVD), systemic arterial hypertension, and left ventricular hypertrophy. The main objective of the present study was to assess cardiovascular parameters in canine HC, based on investigating survival-related variables. The study also aimed to evaluate the influence of concurrent preclinical (MVD) on dogs` survival and the impact of HC on MVD progression. Materials, Methods & Results: A total of 25 dogs with spontaneous HC were enrolled and divided into 2 subgroups accordingly to their echocardiographic findings: group HC (normal echocardiography at first evaluation, n = 16); and group HC + MVD (concurrent presence of stages B1 and B2 MVD diagnosed at the first evaluation, n = 9). The patients were evaluated at diagnosis (T0); 6 months after treatment begging (T1); and after 12 months of treatment (T2). The owners were further contacted by phone or e-mail for 1 more year after T2 regarding survival information. A control group (CG, n = 20) was also evaluated at T0 and T1. At each evaluation, dogs were submitted to a complete clinical evaluation and physical exam, associated with a minimum database (CBC, serum biochemistry, and urine analysis) and cardiovascular evaluation composed of systolic blood pressure determination, electrocardiogram (ECG), and echodopplercardiography. In the HC group, 11/16 dogs underwent the evaluation at T2, while 4/9 dogs from the HC + MVD group and 17/20 dogs from the CG underwent the evaluation at T2. Five dogs (31.25%) from the HC group and 4 dogs (44.44%) from the HC + MVD group died before the end of the follow-up period. In the control group, only 1 dog (5.26%) died before the end of the study. Despite the higher mortality in the HC + MVD group during the follow-up period, there was no significant difference (P = 0.632) in survival when compared with the HC group. The MVD of 4 dogs included in the HC + MVD group was classified as stage B1, while the other 5 dogs were classified as stage B2. Only 1 dog from the CG developed stage B1 MVD in the period studied; however, progression of the MVD stage was documented in 1/4 of dogs in the HC + MVD group and MVD development was documented in 3/11 of dogs from the HC group from T0 to T2. The odds ratio (OR) and respective 95% confidence interval (95%CI) for HC as a risk factor for MVD progression were 4.267 (0.4268 - 42.65; P = 0.342). Exercise intolerance (12/16 dogs) and dyspnea (6/16 dogs) were the cardiorespiratory clinical signs with the highest incidence in the HC group at T0. When compared to the control group, both exercise intolerance (P < 0.001) and dyspnea (P = 0.03) occurrence were significantly higher in the HC group. The age (P = 0.001) and the occurrence of dyspnea (P = 0.036) at diagnosis were significantly higher in dogs with HC that died during the follow-up than those that remained alive. Regarding the occurrence of cardiac arrhythmias verified by ECG, no statistically significant differences were observed among groups. Discussion: The study suggests that systemic hypertension and altered echocardiographic measurements did not interfere with dogs' survival; however, dyspnea was associated with a worse prognosis. Finally, it is possible to conclude that mitral valve degeneration is a common comorbidity in dogs with HC, however, it was not evidenced their interference in the survival of dogs with this endocrine disease or even a role of the HC in the progression of the MVD.


Assuntos
Animais , Cães , Fenômenos Fisiológicos Cardiovasculares , Síndrome de Cushing , Dispneia , Hipertensão/veterinária , Valva Mitral/patologia , Estudos Prospectivos
6.
Rev. Ciênc. Agrovet. (Online) ; 22(2): 251-259, mai. 2023. tab, graf
Artigo em Português | VETINDEX | ID: biblio-1445018

Resumo

Cordia trichotoma é uma espécie de grande interesse econômico, contudo as informações de suas necessidades nutricionais ainda são incipientes. Dessa forma, objetivou-se avaliar a eficiência e doses adequadas de fontes de fertilizantes para produção de mudas de Cordia trichotoma. O experimento foi conduzido em delineamento inteiramente casualizado, em fatorial 3x5, com três fontes defertilizantes, sendo dois adubos de liberação lenta e uma fonte prontamente solúvel (MAP, combinado com KCl), nas doses de 0, 50, 100, 150 e 200%, em relação a dose recomendada. Aos 270 dias, realizou-se a mensuração das variáveis altura, diâmetro de coleto, massa seca e Índice de Qualidade de Dickson. Para cada variável, foi realizado o cálculo da dose máxima de eficiência técnica (DMET). O uso de MAP e KCl proporcionou crescimento superior das mudas em relação às fontes de ALL, para todas as variáveis avaliadas. As médias de DMET encontradas para o ALL1, ALL2 e MAP e KCl foram de 195%, 190% e 120%, respectivamente. Assim, recomenda-se o uso de MAP e KCl, na dose de 120%, ou seja, 0,08 g L-1de KCl e 0,12 g L-1de MAP para fertilização de mudas de Cordia trichotoma.(AU)


Cordia trichotoma is a species of great economic interest, however information on itsnutritional requirement is still incipiente. Thus, the objective was to evaluate the efficiency and adequate doses ofdifferent sources of fertilizers, for the production of Cordia trichotomaseedlings. The experiment was conducted in a completely randomized design (DIC), in a 3 x 5 factorial, with three different sources of fertilizers, two slow-release fertilizers (ALL1 and ALL2) and the use of readily soluble sources (MAP and KCl). The second factor represents the tested doses 0, 50, 100, 150 and 200%, in relation to a dose considered standard. The doses of the slow-release fertilizer were based on the standard dose of0.44 g seedlings-1, while the readily soluble fertilizer doses were of a fixed dose of 0.08 g seedlings-1 of KCl, and increasing doses ofMAP, based on the standard dose of 0.1 g changes -1. At 270 days after sowing, the variables height, collecting diameter, dry mass and Dickson's Quality Index were measured. For each variable, the maximum technical efficiency dose (DMET) was calculated. The use of MAP and KCl provided superior growth of seedlings in relation to ALL sources, for all variables evaluated. The DMET found for ALL1, ALL2 and MAP and KCl were 200%, 200% and 120%, respectively. Thus, it is recommended to use MAP and KCl, at a doseof 120%, that is, 0.08 g L-1of KCl and 0.12 g L-1 of MAP for fertilization of Cordia trichotomaseedlings.(AU)


Assuntos
Fenômenos Fisiológicos Vegetais , Cordia/crescimento & desenvolvimento , Fertilizantes/análise
7.
Rev. Ciênc. Agrovet. (Online) ; 22(2): 260-267, mai. 2023. graf
Artigo em Português | VETINDEX | ID: biblio-1445021

Resumo

Mundialmente, a produção de hortaliças, incluindo os pimentões, está relacionada ao manejo intensivo do solo e, consequentemente, à degradação do mesmo. A implantação de manejos conservacionistas têm se intensificado para a redução dos danos resultantes da produção de manejo convencional. Neste sentido, objetivodo estudo foi de avaliar o desenvolvimento e produtividade do pimentão cultivado em sistema de plantio direto sobre diferentes coberturas vegetais, indicando as espécies com maior potencial pera essa utilização. Para tanto, os tratamentos utilizados foram: Controle (manejo convencional); milheto; crotalária; combinação de coberturas (milheto e crotalária) e plantas espontâneas. As variáveis avaliadas foram: fotossíntese líquida, condutância estomática, concentração de CO2, transpiração, eficiência do uso da água, eficiência instantânea de carboxilação e produtividade. Verificou-se que todas coberturas, melhoraram as características de comprimento e massa de fruto. No quesito de número de frutos por planta e produtividade a cobertura mix superou o restante. A cobertura com plantas espontâneas resultou em maiores concentração intracelular, condutância estomática e transpiração, enquanto que o tratamento mix possibilitou a obtenção de maior valor de fotossíntese líquida, eficiência do uso da água e eficiência instantânea de carboxilação. O maior incremento na produção e capacidade fotossintética ocorreu na utilização de milheto e crotalária.(AU)


Worldwide, the production of vegetables, including peppers, is related to intensive soil management and, consequently, to soil degradation. The implementation of conservationist managements has been intensified to reduce the damage resulting from the production of conventional management. In this sense, the objective of the study was to evaluate the development and productivity of sweet pepper grown in a no-tillage system under different vegetation cover, indicating the species with the greatest potential for this use. Therefore, the treatments used were: Control (conventional management); millet; sunn hemp; combination of cover crops (millet and sunn hemp) and spontaneous plants. The variables evaluated were: net photosynthesis, stomatal conductance, CO2 concentration, transpiration, water use efficiency, instantaneous carboxylation efficiency and productivity. It was found that all coverages improved the characteristics of length and fruit mass. In terms of number of fruits per plant and productivity, the mix coverage surpassed the rest. Coverage with weeds resulted in higher intracellular concentration, stomatal conductance and transpiration, while the mix treatment made it possible to obtain higher net photosynthesis value, water use efficiency and instantaneous carboxylation efficiency. The greatest increase in production and photosynthetic capacity occurred in the use of millet and sunn hemp.(AU)


Assuntos
Capsicum/fisiologia , Fenômenos Fisiológicos Vegetais , Tratamento do Solo
8.
Ciênc. rural (Online) ; 53(1): e20210515, 2023. tab, graf
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1375165

Resumo

ABSTRACT: This study evaluated the physical and physiological qualities and productivity of corn seeds, a variety UFVM 100 Native, produced in plots fertilized in top dressing with different levels of poultry waste. The experiment was organized in a randomized block design, with six treatments and four repetitions, totaling 24 plots. The treatments consisted of the application of 0.0, 1.5, 3.0, 4.5, 6.0, and 7.5 t/ha of tanned poultry waste. The seeds were subjected to the following evaluations: uniformity test, thousand seed weight, germination, vigor (first germination count, accelerated aging, soilless cold test, percentage, and emergence rate in sand), and productivity. Linear regression models were used to evaluate the effects of different dosages of poultry waste on the variables considered. The quality of seeds was not influenced by the effects of different levels of fertilization. Among the dosages used, 7.5 t/ha is recommended because it provides a greater increase in productivity, which may result in a greater financial return to the producer.


RESUMO: Este trabalho teve como objetivo avaliar as qualidades física e fisiológica, bem como a produtividade das sementes de milho, variedade UFVM 100 Nativo, produzidas em lavouras adubadas com diferentes níveis de resíduo avícola, em cobertura. O experimento foi instalado no delineamento em blocos casualizados, com seis tratamentos e quatro repetições, totalizando 24 parcelas. Os tratamentos consistiram da aplicação de 0,0; 1,5; 3,0; 4,5; 6,0 e 7,5 t/ha de resíduo avícola curtido. As sementes foram submetidas às seguintes avaliações: Teste de uniformidade, peso de mil sementes, germinação, vigor (primeira contagem de germinação, envelhecimento acelerado, teste de frio sem solo, porcentagem e velocidade de emergência em areia) e produtividade. Para avaliar o efeito das diferentes dosagens de resíduo avícola sobre as variáveis consideradas foram utilizados modelos de regressão linear. A qualidade das sementes não foi influenciada pelo efeito dos diferentes níveis de adubação. Dentre as dosagens utilizadas, recomenda-se a de 7,5 t/ha por proporcionar maior aumento da produtividade, o que poderá resultar em maior retorno financeiro ao produtor.

9.
Sci. agric ; 80: e20210142, 2023. ilus, tab, mapa, graf
Artigo em Inglês | VETINDEX | ID: biblio-1367270

Resumo

Adaptation to climate change is a strategy for crops to cope with the scenario of rising temperatures worldwide. In the case of Coffea arabica L., the use of agroforestry systems (AFS) with woody species is a promising practice to reduce excessive heat during the day. This study aimed to 1) evaluate air temperature changes that occur in an AFS of coffee and double alleys of rubber trees (Hevea brasiliensis Müell. Arg.) and 2) carry out an analysis of future warming scenarios by comparing the cultivation of Arabic coffee in full sun and in an AFS of double alleys of rubber trees. The microclimatic variables were measured between two rows of coffee trees at 1.0 m of height from June 2016 to June 2018. The results indicate that the AFS with double alleys of rubber trees spaced 16 m apart had an average temperature reduction from 1.4 to 2.5 °C from 10h00 to 16h00. The study also simulated temperature increases of 1.7, 2.6, 3.1, and 4.8 °C from 2018 to 2099, according to scenarios predicted by the Intergovernmental Panel on Climate Change (IPCC), and the impact in coffee production in Paraná State, Brazil. Using the climatic generator PGECLIMA_R, simulations suggest a progressive reduction of traditional areas suitable for open-grown coffee in the state. Production conditions can be maintained through the AFS, since the systems attenuate mean temperatures by 1-2 °C. We conclude that the AFS of coffee and rubber trees contribute to coffee crop adaptations to a future warmer environment.


Assuntos
Mudança Climática/estatística & dados numéricos , Adaptação Fisiológica , Hevea , Coffea/crescimento & desenvolvimento , Florestas
10.
Ciênc. rural (Online) ; 53(1): 1-8, 2023. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1410498

Resumo

This study evaluated the physical and physiological qualities and productivity of corn seeds, a variety UFVM 100 Native, produced in plots fertilized in top dressing with different levels of poultry waste. The experiment was organized in a randomized block design, with six treatments and four repetitions, totaling 24 plots. The treatments consisted of the application of 0.0, 1.5, 3.0, 4.5, 6.0, and 7.5 t/ha of tanned poultry waste. The seeds were subjected to the following evaluations: uniformity test, thousand seed weight, germination, vigor (first germination count, accelerated aging, soilless cold test, percentage, and emergence rate in sand), and productivity. Linear regression models were used to evaluate the effects of different dosages of poultry waste on the variables considered. The quality of seeds was not influenced by the effects of different levels of fertilization. Among the dosages used, 7.5 t/ha is recommended because it provides a greater increase in productivity, which may result in a greater financial return to the producer.


Este trabalho teve como objetivo avaliar as qualidades física e fisiológica, bem como a produtividade das sementes de milho, variedade UFVM 100 Nativo, produzidas em lavouras adubadas com diferentes níveis de resíduo avícola, em cobertura. O experimento foi instalado no delineamento em blocos casualizados, com seis tratamentos e quatro repetições, totalizando 24 parcelas. Os tratamentos consistiram da aplicação de 0,0; 1,5; 3,0; 4,5; 6,0 e 7,5 t/ha de resíduo avícola curtido. As sementes foram submetidas às seguintes avaliações: Teste de uniformidade, peso de mil sementes, germinação, vigor (primeira contagem de germinação, envelhecimento acelerado, teste de frio sem solo, porcentagem e velocidade de emergência em areia) e produtividade. Para avaliar o efeito das diferentes dosagens de resíduo avícola sobre as variáveis consideradas foram utilizados modelos de regressão linear. A qualidade das sementes não foi influenciada pelo efeito dos diferentes níveis de adubação. Dentre as dosagens utilizadas, recomenda-se a de 7,5 t/ha por proporcionar maior aumento da produtividade, o que poderá resultar em maior retorno financeiro ao produtor.


Assuntos
Sementes , Zea mays , Fertilização
11.
Ciênc. rural (Online) ; 53(11): e20220365, 2023. tab, ilus, graf
Artigo em Inglês | VETINDEX | ID: biblio-1427326

Resumo

Plants use light as a source of energy in the process of photosynthesis. Different levels of luminosity cause physiological and morphological changes in the plant, and its success depends on its adaptation to these different levels. Light emitting diodes (LED) have been proposed as a light source in controlled environments. The present research evaluated physiological and morphological aspects in Eucalyptus benthamii (Myrtaceae) seedlings kept under different colors of LED lamps and submitted to water stress. The experiment was carried out in a completely randomized design, in which the treatments were defined as: T1 (control, with white light); T2 (blue light); T3 (red light) and T4 (mixed blue and red light). Red light resulted in the best response to most morphological variables in plant growth. In response to water stress, blue light LEDs resulted in a better seedling response, with slower reduction of photosynthetic rate and other variables. This may indicate the possibility of reducing water deficit damage in seedlings acclimated to blue light prior to field planting.


As plantas utilizam a luz como fonte de energia no processo de fotossíntese. Diferentes níveis de luminosidade causam mudanças fisiológicas e morfológicas na planta, e o seu sucesso depende da sua adaptação a esses diferentes níveis. Diodos de emissão de luz (LED) têm sido propostos como fonte luminosa para ambientes controlados. O objetivo do presente trabalho foi avaliar aspectos fisiológicos e morfológicos em mudas de Eucalyptus benthamii (Myrtaceae) mantidas sob diferentes cores de lâmpadas LED e submetidas ao estresse hídrico. Foram realizados dois experimentos, sendo que um avaliou o efeito de diferentes cores de LEDs no crescimento das mudas e outro analisou o efeito das luzes na aclimatação das mudas e após exposição a deficit hídrico. O experiment foi conduzido em delineamento inteiramente casualizado, em que os tratamentos foram definidos como T1 (controle, com luz branca); T2 (luz azul); T3 (luz vermelha) e T4 (luz azul e vermelha mista). A luz vermelha resultou em melhor resposta para a maioria das variáveis morfológicas no crescimento das plantas. Emresposta ao estresse hídrico, os LEDs de luz azul resultaram em uma melhor resposta das mudas, reduzindo mais lentamente a taxa fotossintética e demais variáveis. Isso pode indicar a possibilidade de reduzir os danos de deficit hídrico nas mudas aclimatadas com luz azul anteriormente ao plantio a campo.


Assuntos
Iluminação , Desidratação , Eucalyptus/crescimento & desenvolvimento , Desenvolvimento Vegetal , Aclimatação
12.
Sci. agric ; 80: e20220121, 2023. tab, graf, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1509211

Resumo

Traditional germination tests which assess seed quality are costly and time-consuming, mainly when performed on a large scale. In this study, we assessed the efficiency of X-ray imaging analyses in predicting the physiological quality of tomato seeds. A convolutional neural network (CNN) called mask region convolutional neural network (MaskRCNN) was also tested for its precision in adequately classifying tomato seeds into four seed quality categories. For this purpose, X-ray images were taken of seeds of 49 tomato genotypes (46 Solanum pennellii introgression lines) from two different growing seasons. Four replicates of 25 seeds for each genotype were analyzed. These seeds were further assessed for germination and seedling vigor-related traits in two independent trials. Correlation analysis revealed significant linear association between germination and image-based variables. Most genotypes differed in terms of germination and seed development performance considering the two independent trials, except LA 4046, LA 4043, and LA4047, which showed similar behavior. Our findings point out that seeds with low opacity and percentage of damaged seed tissue and high values for living tissue opacity have greater physiological quality. In short, our work confirms the reliability of X-ray imaging and deep learning methodologies in predicting the physiological quality of tomato seeds.


Assuntos
Raios X , Redes Neurais de Computação , Solanum lycopersicum/fisiologia , Germinação
13.
Ciênc. anim. bras. (Impr.) ; 24: 73559P, 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1430190

Resumo

The objective of this study was to evaluate the seasonal effect of months of the year upon the physiological and productive responses of crossbred dairy cows raised in an Amazonian climate. Twenty lactating cows were evaluated, fed on Brachiaria decumbens pasture, with free access to water and mineral supplementation. Data from climate variables air temperature (AT), relative humidity (RH), rainfall (RA) and temperature and humidity index (THI) were recorded dur ing the months of January to April 2019. The physiological data collected were: respiratory rate (RR, mov/min), heart rate (HR, beats/min), rectal temperature (RT, ºC), udder surface temperature (UST, ºC), body surface temperature (BST, ºC), dorsum surface temperature (DST, ºC), front surface temperature (FST, ºC) and rear shin temperature (RST). Milk production (MP) was also measured. There was a significant difference (P<0.05) of RST and RR with values ranging from 34.8 to 35.5°C and 32.0 to 36.2 mov/min, respectively. There were no significant difference (P>0.05) for BST, and the values for MP and THI were 3.8; 3.8; 4.6; 4.1 kg and 77.7; 79.7; 80.6; 80.1, respectively. It was concluded that there was a seasonal effect of the months of the year evaluated on the respiratory rate of animals, however, it did not change the MP and the THI. The Amazon environment is conducive to causing thermal stress in lactating cows raised on pasture, requiring the use of shading to facilitate the ability of these animals to dissipate heat.(AU)


O objetivo desse estudo foi avaliar os efeitos sazonais dos meses do ano sobre as respostas fisiológicas e produtivas de vacas leiteiras mestiças criadas em clima amazônico. Foram avaliadas 20 vacas lactantes, alimentadas com pasto de Brachiaria decumbens, com acesso livre a água e suplementação mineral. Foram registrados dados das variáveis climáticas temperatura do ar (TA), umidade relativa do ar (UR), precipitação pluviométrica (PP) e índice de temperatura e Umidade (ITU) durante os meses de janeiro a abril de 2019. Os dados fisiológicos coletados foram: frequência respiratória (FR, mov/min), frequência cardíaca (FC, bat./min), temperatura retal (TR, ºC), temperatura superficial do úbere (TSU, ºC), temperatura superfície corporal (TSC, ºC), temperatura superficial do dorso (TSD, ºC), temperatura superficial da fronte (TSF, ºC) e temperatura superficial da canela (TSCA, °C). Também foi mensurada a produção de leite (PL, kg). Houve diferença significativa (P<0,05) da TSCA e FR com valores variando de 34,8 a 35,5°C e 32,0 a 36,2 mov/min, respectivamente. Não houve diferença significativa (P>0,05) para TSC e os valores observados para PL e ITU foram 3,8; 3,8; 4,6; 4,1 kg e 77,7; 79,7; 80,6; 80,1, respectivamente. Houve efeito sazonal dos meses avaliados sobre a taxa respiratória dos animais, no entanto, isso não alterou a PL nem o ITU. O ambiente amazônico é propício a causar estresse térmico em vacas lactantes mantidas a pasto, sendo necessário o uso de sombreamento para facilitar a capacidade de dissipação de calor corporal desses animais.(AU)


Assuntos
Animais , Feminino , Bovinos/fisiologia , Modalidades Fisiológicas , Estações do Ano , Pastagens , Resposta ao Choque Térmico/fisiologia , Brachiaria
14.
J. Anim. Behav. Biometeorol ; 11(3): e2023027, 2023. graf, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1509957

Resumo

We aimed to assess the physiological and biophysical responses of Nellore bulls exposed to solar radiation in semiarid conditions throughout the day. Sixteen Nellore bulls were examined in Tibau city, Northeast Brazil (5°52ʹ South, 37°20ʹ West, and 37 m above sea level) over four nonconsecutive days, with data collection taking place at one-hour intervals between 7:00 am and 5:00 pm. Four animals were analyzed each day and kept exposed to the sun for the duration of the study. The average age of the animals was three years, and their average body weight was 650±32 kg. The meteorological station measured air temperature (°C), relative humidity (%), solar radiation (W.m-2 ), and black globe temperatures (°C) every minute, while a digital anemometer thermohygrometer measured wind speed (m.s-1 ) at the same time. Respiratory rate (breaths.min-1 ), expired air temperature (°C), rectal temperature (°C), and body surface temperature (°C) were measured as physiological variables. Biophysical equations were used to estimate the sensible and latent heat transfer mechanisms (W.m-2 ). The air temperature ranged from 28.5 to 32.5°C, and direct solar radiation was between 21 and 891 W.m-². Between 11:00 am and 1:00 pm, the study observed heat gain through longwave radiation, which reached an average of 250 W.m-2 , with a significant increase (P < 0.05) in respiratory rate and body surface temperature during this time. Convection was significant in heat dissipation, particularly when the wind speed was increased from 11:00 am. However, latent heat loss mechanisms were more effective in losing excess body heat under total sun exposure, despite the positive effect of convection. The study findings showed that Nellore bulls maintained their body temperature within a narrow range even when exposed to high solar radiation, thus demonstrating the efficiency of physiological and biophysical mechanisms during times of greater thermal challenge.(AU)


Assuntos
Animais , Masculino , Bovinos/fisiologia , Exposição à Radiação/análise , Transtornos de Estresse por Calor
15.
Braz. j. biol ; 83: e272616, 2023. tab, graf, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1439643

Resumo

The extracts of medicinal plants are used for the treatment of seeds in order to reduce the action of phytopathogens and increase the vigor of the seeds. Currently, computerized image analysis has been used to assess the physiological quality of seed lots. The objective was to evaluate the efficiency of the Vigor-S® software in the evaluation of the physiological quality of cowpea seeds treated with essential oils, comparing with a traditional test and the principal component analysis. Two cowpea cultivars were analyzed, BRS Tumucumaque and BRS Guariba, treated with doses of natural extracts of Alfavaca, garlic, horsetail, citronella and pyroligneous acid. The traditional method consisted of evaluations for germination, first germination count, seedling emergence, emergence speed index, accelerated aging, fresh matter and dry matter of seedling and the image analysis for: seedling length, growth index, uniformity index, vigor index, and germination. A Principal component analysis was applied to reduce the number of variables. Horsetail, Alfavaca and citronella extracts were efficient in increasing the physiological quality of the seeds of at least one cultivar. The Vigor-S® software proved to be efficient compared to traditional tests to assess the physiological quality of seeds. Principal Component Analysis is an ally to identify the best extracts and doses to be used. The image analysis method proved to be effective when compared to the traditional method and can therefore be used.


Os extratos de plantas medicinais são utilizados para o tratamento de sementes com o objetivo de diminuir a ação de fitopatógenos e aumentar o vigor das sementes. Atualmente, a análise computadorizada de imagens tem sido utilizada para avaliar a qualidade fisiológica de lotes de sementes. O objetivo foi avaliar a qualidade fisiológica de sementes de feijão-caupi tratadas com óleos essenciais, comparado com teste tradicional, análise imagem e a análise de componentes principais. Foram analisadas duas cultivares de feijão-caupi, BRS Tumucumaque e BRS Guariba, tratadas com doses de extratos naturais de alfavaca, alho, cavalinha, citronela e ácido pirolenhoso. O método tradicional consistiu em avaliações de germinação, primeira contagem de germinação, emergência de plântulas, índice de velocidade de emergência, envelhecimento acelerado, matéria fresca e matéria seca da plântula e a análise de imagem para: comprimento da plântula, índice de crescimento, índice de uniformidade, índice de vigor e germinação. Uma análise de componentes principais foi aplicada para reduzir o número de variáveis. Os extratos de cavalinha, alfavaca e citronela foram eficientes em aumentar a qualidade fisiológica das sementes de pelo menos uma cultivar. O software Vigor-S® mostrou-se eficiente em relação aos testes tradicionais para avaliação da qualidade fisiológica de sementes. A Análise de Componentes Principais é uma aliada para identificar os melhores extratos e doses a serem utilizados. O método de análise de imagens mostrou-se eficaz quando comparado ao método tradicional, podendo, portanto, ser utilizado.


Assuntos
Plantas Medicinais , Óleos Voláteis , Extratos Vegetais , Vigna/crescimento & desenvolvimento
16.
Arq. bras. med. vet. zootec. (Online) ; 75(4): 554-560, July-Aug. 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1447339

Resumo

The purpose of this study was to investigate whether intravenous crotalphine produces significant sedation, as well as physiological changes, in healthy standing horses. Six mares, aged 8 years and weighing 415kg underwent three different treatments in a crossover design: TA (acepromazine: 50µg.kg-1), TC (crotalphine: 0.01µg.kg-1) and TX (xylazine: 1000µg.kg-1), intravenously. At various time points over 60 minutes, physiologic variables were recorded: heart rate, respiratory rate, and rectal temperature. The head height from the ground (HHG) was evaluated in centimeters. Data were analyzed using ANOVA followed by Dunnett's test or Friedman followed by Dunn's test, under 5% significance. Heart rate decreased significantly at M5 and M10 compared with Mb in TX (28±7, 26±6 and 40±8 beats/minute-1, respectively; p=0.0004). Respiratory rate and rectal temperature did not differ among groups or time points. The HHG significantly decreased in all groups compared with Mb at various time points (p<0.0001). In conclusion, crotalphine did not produce reliable and durable sedation in healthy standing mares and did not influence cardiorespiratory variables in a clinically relevant manner.


O objetivo deste estudo foi investigar se a administração de crotalfina intravenosa produz sedação significativa e alterações fisiológicas em equinos saudáveis. Seis éguas, idade média de oito anos e peso médio de 415kg, foram submetidas a três tratamentos distintos: TA (acepromazina: 50µg/kg), TC (crotalfina: 0,01µg/kg) e TX xilazina: 1000µg/kg), por via intravenosa. Em vários momentos, ao de longo de 60 minutos, as variáveis fisiológicas registradas foram frequência cardíaca, frequência respiratória e temperatura retal. A altura de cabeça ao solo (ACS) foi avaliada em centímetros. Os dados foram analisados pela ANOVA, seguida pelo teste de Dunnett ou de Friedman e, depois, pelo teste de Dunn, sob 5% de significância. A frequência cardíaca diminuiu significativamente em M5 e M10 em comparação com Mb em TX (28±7, 26±6 e 40±8 bpm, respectivamente; P=0,0004). A frequência respiratória e a temperatura retal não diferiram entre os grupos ou os pontos de tempo. O HHG diminuiu significativamente em todos os grupos em comparação com Mb em vários momentos (P <0,0001). Em conclusão, a crotalfina não produziu sedação confiável e durável em éguas saudáveis e não influenciou as variáveis cardiorrespiratórias de maneira clinicamente relevante.


Assuntos
Animais , Xilazina , Cavalos , Hipnóticos e Sedativos , Relaxamento Muscular
17.
Acta Vet. Brasilica ; 17(1): 70-74, 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1436343

Resumo

Different anesthetic combinations are used for orchiectomy in cats. This study aimed to evaluate the anesthetic and cardiopulmonary effects on the physiological variables of ketamine (10 mg/kg), midazolam (0.2 mg/kg) and methadone (0.3 mg/kg), combined with local anesthesia, in cats undergoing orchiectomy (n = 19 cats). The time for lateral recumbency, degree of sedation, muscle relaxation and nociception were recorded preoperatively. The propofol rescue dose was recorded. The time to head up and quality of recovery were evaluated postoperatively. The time for lateral recumbency was 5 ± 2 minu-tes. Fifteen minutes after the administration of the ketamine-midazolam-methadone combination, a greater sedative effect, muscle relaxation and less response to noxious stimulation were observed. Propofol was administered to twelve cats under local anesthesia, at a total dose of 1.5 ± 0.8 mg/kg. Surgery was started 28 ± 5 minutes after the administration of ketamine--midazolam-methadone combination. There were no differences in the physiological variables evaluated over the other evalu-ation times (p > 0.05). The recovery quality scores were adequate, and the time to head up was 51 ± 10 minutes. Under the conditions of this study, the ketamine-midazolam-methadone combination did not allow local anesthesia for orchiectomy. Many cats required propofol rescue prior to surgery. This combination promoted minimal changes in physiological variables and prolonged anesthetic recovery.(AU)


Diferentes combinações anestésicas são usadas para orquiectomia em gatos. O objetivo deste estudo foi avaliar o efeito anestésico e as alterações promovidas nas variáveis fisiológicas pela cetamina (10 mg/kg), midazolam (0.2 mg/kg) e metadona (0.3 mg/kg), combinados com anestesia local, em gatos submetidos à orquiectomia (n = 19 gatos). O tempo para adoção do decúbito lateral, grau de sedação, relaxamento muscular e nocicepção foram registrados no pré-operatório. A dose de resgate de propofol foi registrada. O tempo para o gato erguer a cabeça e a qualidade da recuperação foram avaliados no pós-operatório. O tempo para adoção do decúbito lateral foi de 5 ± 2 minutos. Quinze minutos após a administração da associação cetamina-midazolam-metadona, observou-se maior efeito sedativo e relaxamento muscular, e menor resposta à estimulação nociva. O propofol foi administrado em doze gatos para realização de anestesia local, utilizando a dose total de 1.5 ± 0.8 mg/kg. A cirurgia foi iniciada 28 ± 5 minutos após a administração de cetamina-midazolam-metadona. Não houve diferença nas variáveis fisiológicas avaliadas em relação aos demais tempos de avaliação (p > 0.05). Os escores de qualidade de recuperação foram adequados e o tempo para o gato erguer a cabeça foi de 51 ± 10 minutos. Nas condições deste estudo, cetamina-midazolam-metadona não permitiu a realização da anestesia local para orquiectomia. Muitos gatos precisaram de resgate com propofol antes de iniciar a cirurgia. Essa associação promoveu alterações mínimas nas variáveis fisiológicas e longa recuperação anestésica.(AU)


Assuntos
Animais , Masculino , Midazolam/efeitos adversos , Gatos/cirurgia , Ketamina/efeitos adversos , Metadona/efeitos adversos , Orquiectomia/métodos , Anestesia Local/veterinária
18.
Acta Vet. Brasilica ; 17(1): 36-43, 2023. tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1436317

Resumo

The aim of this study was to evaluate the effects of three fresh-water samples with different hardness values (25, 250, and 750 mg L-1 CaCO3) and a control (sea water with salinity 15% and hardness 2500 ± 130.9 mg L-1 CaCO3) on Mugil liza (mullet) juveniles by conducting a long-term test (for 50 days). Zootechnical performance [weight gain (WG), feed conversion rate, specific growth rate, and survival (%)], stress indicator parameters (glucose), and physiological parameters in gill tissues were analyzed to determine the fresh-water hardness range that can allow the optimal survival, growth, and feed conversion for the species. Fish with a mean initial weight of 22 ± 2.84 g were maintained under constant conditions of temperature, pH, alkalinity, and ammonia concentration, and they were fed four times per day with a commercial diet. When evaluating zootechnical performance, only survival (%) was not significantly different among treatments. For the other variables­weight gain, feed conversion, and specific growth rate­the best results were found in the treatment with 15% salinity (control). Blood glucose levels in animals maintained at 15% salinity (control) were significantly lower than those observed in the other treatments. Histological analyses corroborated the zootechnical data, potentially indicating stress in fish maintained at very low and very high water hardness. In conclusion, for cultivating juvenile mullets in fresh water, the most suitable hardness value was 250 mg L-1 CaCO3, because the best final weight of fish was achieved in that condition.(AU)


O objetivo desse estudo foi avaliar o efeito de três durezas diferentes de água doce (25, 250 e 750 mg.L-1 CaCO3) e controle (água do mar com salinidade 15 % e dureza 2500 ± 130,9 mg.L-1 CaCO3), em juvenis de tainha Mugil Liza , através de um teste de longo prazo (50 dias), avaliando o desempenho zootécnico (ganho de peso (GP), conversão alimentar (CA), taxa de crescimento específico (TCE) e sobrevivência (%)), parâmetros indicadores de estresse (glicose) e avaliação de parâme-tros fisiológicos nos tecidos das brânquias, a fim de determinar a faixa de dureza em água doce onde há melhor sobrevivência, crescimento e conversão alimentar dessa espécie. Os peixes com peso médio inicial de 22 ± 2,84g foram mantidos em condi-ções constantes de temperatura, pH, alcalinidade e amônia, e alimentados quatro vezes ao dia com dieta comercial. Ao avaliar o desempenho zootécnico apenas a sobrevivência (%) não foi significativamente diferente entre os tratamentos, porém, para as demais variáveis: ganho de peso (GP), conversão alimentar (CA) e taxa de crescimento específico (TCE) os melhores resul-tados foram encontrados no tratamento com salinidade 15 % (controle). A glicose no sangue dos animais mantidos a salini-dade 15 % (controle) foi significativamente menor em relação aos outros tratamentos. As análises histológicas corroboram os dados zootécnicos, indicando possivelmente stress nos peixes mantidos em durezas muito baixas e muito altas. Conclui-se que para cultivar juvenis de tainha em água doce, a dureza mais adequada é 250 mg.L-1 CaCO3, pois apresentou melhor peso final dentre as durezas avaliadas.(AU)


Assuntos
Animais , Carbonato de Cálcio/efeitos adversos , Smegmamorpha/fisiologia , Técnicas Histológicas/veterinária , Aquicultura/métodos
19.
Rev. bras. saúde prod. anim ; 24: 20220028, 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1425259

Resumo

The present study aimed at assessing the effects of hepatoprotective agents in diets that contain sources of energy on milk production, milk composition, and nutrient partition in lactating cows. Sixteen Holstein x Gir crossbred mid-lactation cows with an average body weight of 553 ± 85 kg were used in this study. These animals were allocated in a 4x4 Latin square design. A 2x2 factorial arrangement was employed in this feeding experiment. In each treatment, cows received diets with or without a hepatoprotective agent and variable in ground corn grain or citrus pulp as energy sources. Evaluated parameters included nutrient intake and digestibility, milk production, milk composition, energy balance, and nitrogen balance. Performance and nutrient balance variables were assessed and no interaction was observed between the hepatoprotective compounds and the dietary sources of energy. Dry matter intake, milk production and net energy for lactation were higher in corn as an energy source whereas milk fat content was higher in citrus pulp diets. There was a reduction in protein and casein contents in the milk of cows that was supplemented with an hepatoprotective agent. In this study, the hepatoprotective agent improved nitrogen balance in dairy cows. The use of the hepatoprotective compounds in the diet of these lactating cows in confinement reduced the milk protein fraction and favored a higher nitrogen balance in these animals. Retention of nitrogen compounds in the metabolism of lactating cows under confinement is influenced by hepatoprotective agents.(AU)


Objetivou-se com este estudo avaliar os efeitos de fontes de energia associadas a um hepatoprotetor sobre a produção, composição do leite e a partição dos nutrientes em vacas lactantes confinadas. Foram utilizadas 16 vacas mestiças Holandês x Gir no terço médio da lactação, com peso corporal médio de 553 ± 85 kg, distribuídas em delineamento experimental quadrado latino 4x4 quádruplo em arranjo fatorial 2x2. Os tratamentos consistiram de dieta com ou sem a inclusão do hepatoprotetor, e variação de milho moído ou polpa cítrica como fontes de energia. Não houve interação (P>0.05) entre as fontes de energia e o hepatoprotetor para as variáveis de desempenho e balanço de nutrientes. O consumo de matéria seca, a produção de leite, o leite corrigido para 4% de gordura foram maiores (P<0.05) nas dietas com milho moído como fonte de energia. O teor de gordura do leite foi maior (P<0.05) nas dietas com a polpa cítrica. Houve redução (P<0.05) no teor de proteína bruta e caseína no leite das vacas que receberam o hepatoprotetor na dieta. O hepatoprotetor favoreceu maior (P<0.05) retenção e balanço de nitrogênio nas vacas. Portanto, o milho moído pode ser utilizado na dieta como fonte de energia para impulsionar a produção de leite. Enquanto, a fonte de energia proveniente da polpa cítrica afeta a composição do leite, através do incremento no teor de gordura. O uso de hepatoprotetores na dieta favoreceu maior retenção de nitrogênio em vacas lactantes confinadas.(AU)


Assuntos
Animais , Feminino , Bovinos/fisiologia , Leite/química , Medicamentos Hepatoprotetores , Fenômenos Fisiológicos da Nutrição Animal
20.
Acta sci. vet. (Impr.) ; 51: Pub. 1918, 2023. ilus, tab
Artigo em Inglês | VETINDEX | ID: biblio-1443931

Resumo

Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into 2 groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-min wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61 % respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage.


Assuntos
Animais , Alvéolos Pulmonares , Callithrix , Sevoflurano/administração & dosagem , Isoflurano/administração & dosagem , Anestésicos/administração & dosagem , Halogênios
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