The interaction between the environment and embryo development in assisted reproduction

It can be assumed that the natural processes of selection and developmental condition in the animal provide the best prerequisites for embryogenesis resulting in pregnancy and subsequent birth of a healthy neonate. In contrast, circumventing the natural selection mechanisms and all developmental conditions in a healthy animal harbors the risk of counteracting, preventing or reducing the formation of embryos or substantially restricting their genesis. Considering these facts, it seems to be obvious that assisted reproductive techniques focusing on early embryonic stages serve an expanded and unselected germ cell pool of oocytes and sperm cells, and include the culture of embryos outside their natural habitat during and after fertilization for manipulation and diagnostic purposes, and for storage. A significant influence on the early embryonic development is seen in the extracorporeal culture of bovine embryos (in vitro) or stress on the animal organism (in vivo). The in vitro production per se and metabolic as well as endocrine changes in the natural environment of embryos represent adequate models and serve for a better understanding. The purpose of this review is to give a brief presentation of recent techniques aimed at focusing more on the complex processes in the Fallopian tube to contrast in vivo and in vitro prerequisites and abnormalities in early embryonic development and serve to identify potential new ways to make the use of ARTs more feasible.(AU)

Bartonelose: doença de importância para a saúde pública envolvendo a tríade homem-ambiente-animal / Bartonellosis: disease of importance for public health involving the man-environment-animal triad / Bartonelosis: enfermedad de importancia para la salud pública que involucra la triada hombre-ambiente-animal

A relação hospedeiro-parasita é caracterizada como uma interação alelobiótica construída por meio de processos evolutivo-adaptativos com hospedeiros assintomáticos. No ambiente silvestre é notório o equilíbrio desta relação, porém quando há intervenção antropogênica um ciclo enzoótico pode se estabelecer proporcionando o surgimento de enfermidades emergentes ou reemergentes. Dentre estes agentes etiológicos, a Bartonella spp. é um bacilo gram-negativo da classe Proteobacteria que apresentam tropismo por eritrócitos e células endoteliais, com infecção já descrita em animais das Ordens: Rodentia, Lagomorpha, Carnivora, Artiodactyla, Eulipotyphla e Chiroptera. A infecção pela bactéria pode estar associada à linfadenite, endocardite, angiomatose bacilar e peliose hepática em humanos. Treze espécies de Bartonella spp. são tidas como zoonóticas. O objetivo desta revisão está em apontar para a comunidade científica a bartonelose como uma doença de notificação obrigatória, assim como, os possíveis hospedeiros em animais domésticos e silvestres e sua etiopatogenia.(AU)

The host-parasite relationship is characterized as an allelobiotic interaction built through evolutionary-adaptive processes with asymptomatic hosts. In the wild environment, the balance of this relationship is notorious, but when there is anthropogenic intervention, an enzootic cycle can be established, providing the emergence of emerging or reemerging diseases. Among these etiologic agents, Bartonella spp. is a gram-negative bacillus of the Proteobacteria class that presents tropism for erythrocytes and endothelial cells, with infection already described in animals of the Orders: Rodentia, Lagomorpha, Carnivora, Artiodactyla, Eulipotyphla and Chiroptera. Infection by the bacterium may be associated with lymphadenitis, endocarditis, bacillary angiomatosis and peliosis hepatica in humans. Thirteen species of Bartonella spp. are considered zoonotic. The objective of this review is to point out to the scientific community bartonellosis as a notifiable disease, as well as the possible hosts in domestic and wild animals and their etiopathogenesis.(AU)

La relación hospedador-parásito se caracteriza por ser una interacción alelobiótica construida mediante procesos evolutivo-adaptativos con hospedadores asintomáticos. En el medio silvestre, el equilibrio de esta relación es notorio, pero cuando hay intervención antropogénica, puede establecerse un ciclo enzoótico, propiciando la aparición de enfermedades emergentes o reemergentes. Entre estos agentes etiológicos, Bartonella spp. es un bacilo gramnegativo de la clase Proteobacteria que presenta tropismo por eritrocitos y células endoteliales, con infección ya descrita en animales de los Órdenes: Rodentia, Lagomorpha, Carnivora, Artiodactyla, Eulipotyphla y Chiroptera. La infección por la bacteria puede estar asociada a linfadenitis, endocarditis, angiomatosis bacilar y peliosis hepática en humanos. Trece especies de Bartonella spp. se consideran zoonóticas. El objetivo de esta revisión es señalar a la comunidad científica la bartonelosis como enfermedad de declaración obligatoria, así como los posibles hospedadores en animales domésticos y salvajes y su etiopatogenia.(AU)

Seasonal patterns of infestation by monogenean parasites of fish and their relationship with water parameters in two rivers with different disturbance gradients in southeastern Brazil / Padrões sazonais de infestação por parasitos monogenéticos de peixes e sua relação com os parâmetros da água em dois rios com diferentes gradientes de perturbação no sudeste do Brasil

Here, we evaluate the relationships between the infestation rates of five monogenean parasites species with the dry and wet seasons, with the organic and inorganic parameters of the water of two rivers: the Jacaré-Pepira and Jacaré-Guaçú, and with the condition factors of its fish hosts: Serrasalmus maculatus and Astronotus crassipinnis, in the state of São Paulo, southeastern Brazil. Fish were collected between January and December 2017. Anacanthorus serrasalmi, Amphithecium speirocamarotum and Gussevia asota had higher abundance rates (Student's t test, p ≤ 0.05) in the wet season. Gussevia asota had its abundance negatively correlated to nitrate in the Jacaré-Pepira River and with total nitrogen and potassium in the Jacaré-Guaçú River. Regarding the fish hosts condition factors, was observed a positive correlation with the abundances of G. asota in the Jacaré-Guaçú River, and with A. serrasalmi in the Jacaré-Pepira River. In general, wet season favored an increasing in the infestation rates of the monogeneans parasites in their host species, mainly in the river considered as the most polluted, the Jacaré-Guaçú River. Of the five parasites species analyzed in this study, only Gussevia astronoti and Rhinoxenus piranhus had no interaction with seasonality, river water variables, or fish host condition factors. On the other hand, G. asota had interactions both with water parameters (nitrate and total nitrogen) and with the hosts condition factors, which reflected in the abundance and intensity rates, showing itself as a species sensitive to changes in the environment and, therefore, that can be considered as a bioindicator organism.

Aqui, nós avaliamos as relações entre as taxas de infestação de cincos espécies de parasitos monogenéticos em relação aos períodos seco e chuvoso, aos parâmetros orgânicos e inorgânicos da água de dois rios: Jacaré-Pepira e Jacaré-Guaçú, e em relação aos fatores de condição das espécies de peixes hospedeiras: Serrasalmus maculatus e Astronotus crassipinnis, no estado de São Paulo, sudeste do Brasil. Os peixes foram coletados entre os meses de janeiro a dezembro de 2017. Anacanthorus serrasalmi, Amphithecium speirocamarotum e Gussevia asota tiveram maiores taxas de abundância (teste t de Student, p ≤ 0,05) no período chuvoso. Gussevia asota teve sua abundância negativamente correlacionada com o nitrato no rio Jacaré Pepira e com o nitrogênio total e potássio no rio Jacaré-Guaçú. Em relação ao fator de condição dos peixes, foi observado uma correlação positiva com a abundância de G. asota no rio Jacaré-Guaçú e com A. serrasalmi no rio Jacaré-Pepira. No geral, o período chuvoso favoreceu um aumento nas taxas de infestação dos parasitos monogenéticos em seus peixes hospedeiros, especialmente no rio considerado como o mais poluído, o rio Jacaré-Guaçú. Das cinco espécies de parasitos analisadas no estudo, somente Gussevia astronoti e Rhinoxenus piranhus não tiveram nenhum tipo de interação com a sazonalidade, com as variáveis das águas dos rios ou com o fator de condição dos peixes hospedeiros. Por outro lado, G. asota teve interações tanto com os parâmetros da água (nitrato e nitrogênio total) quanto com os fatores de condição dos hospedeiros, que refletiram nas taxas de abundância e de infestação, mostrando que esta espécie é sensível às mudanças no ambiente e que, portanto, pode ser utilizada como um organismo bioindicador.

Performance of Turkeys in Enrichment Environment with Perches and Outdoor Access under Tropical Conditions

Heat stress compromises turkey's productivity and increase mortality mainly in the final stages of growth. This study evaluated the effect of perches and its interaction with outdoor access on turkey performance in high environment temperature humidity index (THI). Turkeys were reared in 1.75 × 5 m indoor floor pens and were fed with a standard commercial diet, offered ad libitum according to the productive phase. All poults were housed indoors until 62 d of age. A free-range area for a replicate of 8.75 m2, with natural shadow, was available from 07:00 to 19:00 h. Final density was 10.33 ± 0.22 kg/m2. The treatments were a combination of a factorial arrangement (2 × 2) with or without perches and, with or without access to the outdoors. From 10:00 and 19:00 THI was above critical level of comfort (heat stress). In indoors turkeys, feed intake (FI) decreased, and water intake increased, panting was observed, and had a significantly lower final body weight (BW) and FI than turkeys allowed outdoors (p<0.05). Perch availability decreased final BW and FI (p<0.05). Differences in weight of breast meat, wings, or thighs between treatments were negligible. In conclusion turkeys with outdoor access from 62 d of age had better performance.(AU)

Enriquecimiento ambiental para gatos hospitalizados / Environmental enrichment for inpatient cats / Enriquecimento ambiental para gatos em ambiente de internação

Muchas patologías pueden afectar a los felinos, lo que determina de forma rutinaria la necesidad de atención veterinaria. El entorno en el que se inserta el gato es extremadamente importante, y en la mayoría de las clínicas veterinarias y hospitales donde estos animales se mantienen en el hospital, las condiciones no son ideales. El enriquecimiento ambiental es una herramienta que busca mejorar la calidad de vida del animal, posibilitando así la anticipación de la recuperación y consecuentemente un mejor pronóstico para el animal. Con el fin de minimizar un posible nivel de estrés que el entorno hospitalario puede determinar al animal, se realizó un estudio experimental en la Clínica Veterinaria Unigran en Dourados - MS, en el que 3 gatos sanos (2 machos y 1 hembra) con un aproximado Los tres años de edad fueron mantenidos en un ambiente de internación para realizar un estudio de comportamiento de los mismos mediante grabaciones de video y posterior análisis mediante etograma. Los videos se realizaron en dos momentos, el primero fue el cubículo de hospitalización sin enriquecimiento ambiental, mientras que el segundo fue introduciendo elementos (arenero, cama y juguetes) como enriquecimiento. El enriquecimiento ambiental ayudó moderadamente a algunos animales, a reducir el tiempo dedicado a algunas de sus conductas incluidas en la forma de estrés, así como también se observó qu

Many pathologies can affect felines, which routinely determines the need for veterinary care. The environment in which the cat is inserted is extremely important, and in most veterinary clinics and hospitals where these animals are kept in hospital, there are less than ideal conditions. Environmental enrichment is a tool that seeks to improve the quality of life of the animal, thus enabling the anticipation of recovery and consequently better prognosis for the animal. In order to minimize a possible level of stress that the hospital environment can determine to the animal, an experimental study was carried out at the Unigran Veterinary Clinic in Dourados - MS, in which 3 healthy cats (2 males and 1 female) with an approximate age of three years they were kept in an inpatient environment to conduct a behavioral study of them through video recordings and subsequent analysis using ethogram. The videos were made in two moments, the first being the hospitalization cubicle without environmental enrichment, while the second was introducing items (sandbox, bed and toys) as enrichment. Environmental enrichment helped moderately some animals, in reducing the time spent on some of their behaviors included in the form of stress, as well as it was observed that animals in general at the time when the management of environmental enrichment was carried out had greater interaction with the hum

Muitas patologias podem acometer felinos, que corriqueiramente determina a necessidade de atendimento veterinário. O ambiente no qual o gato está inserido adquire extrema importância, sendo que na maioria das clínicas e hospitais veterinários em que estes animais são mantidos em internação há condições aquém das ideais. O enriquecimento ambiental, constitui uma ferramenta que busca melhorar a qualidade de vida do animal, possibilitando assim a antecipação da recuperação e consequentemente melhores prognósticos ao animal. Para minimizar um possível nível de estresse que o ambiente de internação pode determinar ao animal, foi realizado um estudo experimental na Clínica Veterinária da Unigran em Dourados - MS, no qual 3 gatos saudáveis (2 machos e 1 fêmea) com idade aproximada de três anos foram mantidos em ambiente de internação para se realizar estudo comportamental dos mesmos por meio de gravações em vídeos e posterior análise utilizando-se etograma. Os vídeos eram efetuados em dois momentos, sendo no primeiro a baia de internação sem enriquecimento ambiental, enquanto no segundo eram introduzidos ítens (caixa de areia, cama e brinquedos) como enriquecimento. O enriquecimento ambiental ajudou de forma moderada alguns animais, na diminuição do tempo despendidos de alguns de seus comportamentos compreendidos na forma de estresse bem como observou-se que os animais de uma maneira

Enriquecimento ambiental para gatos em ambiente de internação / Environmental enrichment for inpatient cats / Enriquecimiento ambiental para gatos hospitalizados

Muitas patologias podem acometer felinos, que corriqueiramente determina a necessidade de atendimento veterinário. O ambiente no qual o gato está inserido adquire extrema importância, sendo que na maioria das clínicas e hospitais veterinários em que estes animais são mantidos em internação há condições aquém das ideais. O enriquecimento ambiental, constitui uma ferramenta que busca melhorar a qualidade de vida do animal, possibilitando assim a antecipação da recuperação e consequentemente melhores prognósticos ao animal. Para minimizar um possível nível de estresse que o ambiente de internação pode determinar ao animal, foi realizado um estudo experimental na Clínica Veterinária da Unigran em Dourados - MS, no qual 3 gatos saudáveis (2 machos e 1 fêmea) com idade aproximada de três anos foram mantidos em ambiente de internação para se realizar estudo comportamental dos mesmos por meio de gravações em vídeos e posterior análise utilizando-se etograma. Os vídeos eram efetuados em dois momentos, sendo no primeiro a baia de internação sem enriquecimento ambiental, enquanto no segundo eram introduzidos ítens (caixa de areia, cama e brinquedos) como enriquecimento. O enriquecimento ambiental ajudou de forma moderada alguns animais, na diminuição do tempo despendidos de alguns de seus comportamentos compreendidos na forma de estresse bem como observou-se que os animais de uma maneira geral no momento em que se realizava o manejo de enriquecimento ambiental possuiam maior interação com o ser humano e desta maneira pode-se recomendar o uso de formas que possam tornar o ambiente mais próximo ao encontrado no domicílio do felino.(AU)

Many pathologies can affect felines, which routinely determines the need for veterinary care. The environment in which the cat is inserted is extremely important, and in most veterinary clinics and hospitals where these animals are kept in hospital, there are less than ideal conditions. Environmental enrichment is a tool that seeks to improve the quality of life of the animal, thus enabling the anticipation of recovery and consequently better prognosis for the animal. In order to minimize a possible level of stress that the hospital environment can determine to the animal, an experimental study was carried out at the Unigran Veterinary Clinic in Dourados - MS, in which 3 healthy cats (2 males and 1 female) with an approximate age of three years they were kept in an inpatient environment to conduct a behavioral study of them through video recordings and subsequent analysis using ethogram. The videos were made in two moments, the first being the hospitalization cubicle without environmental enrichment, while the second was introducing items (sandbox, bed and toys) as enrichment. Environmental enrichment helped moderately some animals, in reducing the time spent on some of their behaviors included in the form of stress, as well as it was observed that animals in general at the time when the management of environmental enrichment was carried out had greater interaction with the human being and in this way it can be recommended the use of ways that can make the environment closer to that found in the feline's home.(AU)

Muchas patologías pueden afectar a los felinos, lo que determina de forma rutinaria la necesidad de atención veterinaria. El entorno en el que se inserta el gato es extremadamente importante, y en la mayoría de las clínicas veterinarias y hospitales donde estos animales se mantienen en el hospital, las condiciones no son ideales. El enriquecimiento ambiental es una herramienta que busca mejorar la calidad de vida del animal, posibilitando así la anticipación de la recuperación y consecuentemente un mejor pronóstico para el animal. Con el fin de minimizar un posible nivel de estrés que el entorno hospitalario puede determinar al animal, se realizó un estudio experimental en la Clínica Veterinaria Unigran en Dourados - MS, en el que 3 gatos sanos (2 machos y 1 hembra) con un aproximado Los tres años de edad fueron mantenidos en un ambiente de internación para realizar un estudio de comportamiento de los mismos mediante grabaciones de video y posterior análisis mediante etograma. Los videos se realizaron en dos momentos, el primero fue el cubículo de hospitalización sin enriquecimiento ambiental, mientras que el segundo fue introduciendo elementos (arenero, cama y juguetes) como enriquecimiento. El enriquecimiento ambiental ayudó moderadamente a algunos animales, a reducir el tiempo dedicado a algunas de sus conductas incluidas en la forma de estrés, así como también se observó que los animales en general en el momento en que se realizaba el manejo del enriquecimiento ambiental tenían mayor interacción con el ser humano y de esta forma se puede recomendar que el uso de formas que puedan acercar el entorno al que se encuentra en el hogar del felino.(AU)

Tratamento da epilepsia idiopática canina - quadro clínico após interação medicamentosa / Treatment of canine idiopathic epilepsy - clinical picture after drug interaction

Background: The large number of diseases demand perennial development of the pharmaceutical industry. The drugtesting phase is essential to make them available safely. Awareness of pharmacological properties, adverse effects and drug interactions is required. Drug interactions are common in veterinary medicine and should be avoided. At times, epileptic seizures require polydrug therapy, predisposing patients to drug interactions. The interaction between carbamazepine and phenobarbital reported in the literature is an example. The aim of this paper is to report a clinical picture of drug interaction in the treatment of idiopathic epilepsy. Case: A 1-year-old Border Collie male dog, was admitted at the Veterinary Hospital of the Federal University of Lavras in post-ictal. The tutor reported that a year ago the animal had epileptic seizures and clusters with intervals of 21 to 25 days. Despite the continued use of previously prescribed phenobarbital (7.4 mg/kg, v.o., BID, until new recommendations) and carbamazepine (7.5 mg/kg, v.o., BID, until new recommendations), seizure control was not achieved. The physical examination indicated, tachypnea, ptialism, mydriasis, intense fatigue, and alienation from the environment. The patient did not respond to the threat-reflex test. Blood count, hepatic and renal blood chemistry, serum electrolyte (potassium, sodium, calcium and phosphorus), and phenobarbital dosages were requested. Based on the animal's history, breed characteristics, and alterations in the physical examination associated with normal results in complementary exams, idiopathic epilepsy was diagnosed. After analyzing the case, it was observed that the inefficiency in the control of seizures was possibly due to the drug interaction between phenobarbital and carbamazepine. Carbamazepine and phenobarbital reciprocally reduce their half-lives. To confirm the raised hypothesis, the serum concentration of carbamazepine was gradually reduced through weaning from its dose administered to the patient. Serial dosage of the concentration of phenobarbital in the bloodstream was performed. As a result, the serum phenobarbital, previously dosed at a concentration of 13.3 mg/dL with concomitant administration of carbamazepine, increased to 22 mg/dL 40 days after the beginning of weaning from carbamazepine (T0), and then to 36 mg/dL 100 days after T0. There was an increase in the concentration of phenobarbital in the bloodstream while the serum concentration of carbamazepine declined. The patient spaced out his seizures to every 50 to 60 days with phenobarbital monotherapy at a dose of 6 mg/kg. Discussion: Efficient control of clusters, such as the reduction of seizures by 50%, was only possible due to the meticulous perception of the possible interaction reported in medicine. Carbamazepine and phenobarbital are P450 isoenzyme inducers. The concomitant administration of both drugs potentiated the action of isoenzymes in the hepatic microsomal system, which led to an accelerated metabolic processing of the drugs. After weaning from carbamazepine, that is, reducing the action of carbamazepine on the isoenzymes of the P450 enzyme system, the concentration of phenobarbital normalized at 36 mg/ dL. Such concentration is within the reference range reported in the literature: 25 mg/dL to 35 mg/dL of serum phenobarbital for treatment efficacy. Therefore, the control of convulsive crises was achieved. The increase in the concentration of phenobarbital due only to weaning from carbamazepine, even after decreasing the daily dose of barbiturate prescribed to the animal, contributed to evidence of the interaction of these drugs. It is noted that prior knowledge of pharmacological properties, careful study of the patient's history, and the cooperation of the tutor were essential for the therapeutic success and practice of evidence-based veterinary medicine.

Water column use by reef fishes of different color patterns

Color in animals responds to selective pressures and mediates the relationship between organism and environment. Reef fishes have the amplest variety of pigment cell types. This color patterns' variety may function as camouflage and be related to spatial use. We tested the hypothesis that the coloration of reef fish relates to water column stratum occupation. We predicted that sedentary animals connected to the background take advantage of background matching or disruptive patterns; more mobile demersal species apply disruptive coloration or motion-dazzle; and that pelagic species tend to have silvery bodies. We classified color patterns and categorized the water column stratum use for the Brazilian reef fishes in FishBase. Our analyses confirmed that irregular contrasting contour breaks, suggestive of disruptive coloration, occurs in benthic species and that silvering color was more prevalent in the pelagic stratum. Our raw data suggested a higher frequency of contrasting regular stripes, typical of motion-dazzle, in demersal species. However, the considerable uncertainty around estimates did not confirm this pattern. Reef fishes coloration is correlated to occupation of different strata in the water column. This can be interpreted as fishes being adapted to these habitats and partially explaining the richness of color patterns among them.(AU)

A cor nos animais responde a pressões seletivas e media a relação entre organismo e ambiente. Peixes recifais têm a maior variedade de tipos de células de pigmento. Essa variedade de padrões de coloração pode funcionar como camuflagem e estar relacionada ao uso espacial. Nós testamos a hipótese de que a coloração dos peixes recifais está relacionada à ocupação do estrato da coluna d'água. Previmos que animais sedentários conectados ao fundo aproveitam a semelhança ao fundo ou padrões disruptivos; espécies demersais mais móveis aplicam coloração disruptiva ou deslumbramento de movimento; e que espécies pelágicas tendem a apresentar corpos prateados. Classificamos os padrões de coloração e categorizamos o uso do estrato da coluna d'água para os peixes recifais brasileiros no FishBase. Nossas análises confirmaram que quebras de contorno irregulares, sugerindo coloração disruptiva, ocorrem em espécies bentônicas e que a cor prateada prevaleceu no estrato pelágico. Nossos dados brutos sugeriram uma maior frequência de listras contrastantes, típicas do deslumbramento de movimento, em espécies demersais. Mas a considerável incerteza dessas estimativas não confirmou esse padrão. A coloração dos peixes recifais está correlacionada com a ocupação de diferentes estratos da coluna d'água. Isso pode ser interpretado como peixes sendo adaptados a estes habitats, explicando em parte a riqueza de padrões de coloração entre eles.(AU)

The role of the oviduct and extracellular vesicles during early embryo development in bovine

The oviduct is an important reproductive structure that connects the ovary to the uterus and takes place to important events such as oocyte final maturation, fertilization and early embryonic development. Thus, gametes and embryo can be directly influenced by the oviductal microenvironment composed by epithelial cells such secretory and ciliated cells and oviductal fluid. The oviduct composition is anatomically dynamic and is under ovarian hormones control. The oviductal fluid provides protection, nourishment and transport to gametes and embryo and allows interaction to oviductal epithelial cells. All these functions together allows the oviduct to provides the ideal environment to the early reproductive events. Extracellular vesicles (EVs) are biological nanoparticles that mediates cell communication and are present at oviductal fluid and plays an important role in gametes/embryo - oviductal cells communication. This review will present the ability of the oviducts based on its dynamic and systemic changes during reproductive events, as well as the contribution of EVs in this process.(AU)

Bactérias resistentes a antibióticos em ambiente aquático: efeito na produção animal / Antibiotic resistant bacteria in aquatic environment: effect on animal production

Objetivou-se discorrer sobre bactérias resistentes a antibióticos veiculadas em ambientes aquáticos, considerando os mecanismos, formas de aquisição e os efeitos à produção animal. A utilização de antibióticos para fins profiláticos, terapêuticos e agropecuários cresceu em larga escala nos últimos anos, levando à perda de eficiência no combate a patógenos. A crise atual dos antibióticos é decorrente de uma falha geral em compreender de forma abrangente a evolução, as fontes, a disseminação e os mecanismos moleculares da resistência, pois os reservatórios ambientais potenciais e suas diversidades genéticas de resistência associadas geralmente não são considerados no desenvolvimento de drogas. Assim, a pressão de seleção aplicada pelos antibióticos em diversos ambientes tem promovido a evolução e disseminação de genes de resistência bacteriana em escala mundial, nos mais variados tipos de ambientes. Resíduos antibióticos persistem no solo e em ambientes aquáticos, este último, atuando como importante reservatório de bactérias, facilitando a troca de material genético entre bactérias ambientais e patogênicas e permitindo a disseminação de genes e modificações no resistoma ambiental. Desta forma, existe uma preocupação tanto para a medicina humana quanto a veterinária devido a diversidade de doenças causadas em humanos e animais domésticos por bactérias multirresistentes. Entender as origens, diversidade e mecanismos de resistência com potencial para impactar animais de produção é de grande importância para identificar os riscos associados a interação entre bactérias de diferentes ecossistemas e o impacto destas à produção animal, seja pelo comprometimento da saúde dos animais e/ou pela contaminação dos produtos produzidos por estes e consequentes danos à saúde humana.

The present review aimed to discuss antibiotic-resistant bacteria transmitted in aquatic environments, regarding the mechanisms, forms of acquisition, and the effects on animal production. The use of antibiotics for prophylactic, therapeutic, and agricultural purposes has grown on a large scale in recent years, leading to a loss of efficiency in combating pathogens. The current antibiotic crisis arises from a general failure to comprehensively understand the evolution, sources, dissemination, and molecular mechanisms of resistance, as potential environmental reservoirs and their associated resistance genetic diversity are generally not considered in drug development. Thus, the selection pressure applied by antibiotics in different environments has promoted the evolution and dissemination of bacterial resistance genes on a worldwide scale, in the most varied types of environments. Antibiotic residues persist in soil and aquatic environments, the latter acting as an important reservoir of bacteria, facilitating the exchange of genetic material between environmental and pathogenic bacteria and allowing the dissemination of genes and modifications in the environmental resistome. Thus, there is a concern for both human and veterinary medicine due to the diversity of diseases caused in humans and domestic animals by multiresistant bacteria. Understanding the origins, diversity, and resistance mechanisms with the potential to impact farm animals is of great importance to identify the risks associated with the interaction between bacteria from different ecosystems and their impact on animal production, either by compromising the health of animals and/or by the contamination of products produced by them and consequent damage to human health.

Is the addition of spray homeopathic in feed able to change dog behavior? / A adição de spray homeopático na ração é capaz de alterar o comportamento de cães?

This study aimed to determine if the homeopathic formulation based on Natrum muriaticum, Matricaria, Chamomilla, and Ignatia amara was effective for stress control in dogs in order to prevent and/or reduce the frequency of unwanted behaviors. Ten male beagle dogs were divided into two groups, with five animals per group. The control group was animals receiving 0.5 mL/day of placebo via spray in the feed for 30 consecutive days as a preventive. The treated group received 0.5 mL/day of tested drug spray in the feed for 30 consecutive days as a preventive. Behavioral tests were performed at two time points, before and after receiving the tested drug. We performed the following behavioral tests: a) persons known and unknown in the internal and external environment; b) interaction with toys; c) interaction with an unknown dog, d) test with a leash; and e) firecracker test. There was more engagement in digging and scaling the fence in the control group than in the treatment group (P < 0.05). The animals that received homeopathic medicine sat 2.54 times longer than the control (P = 0.0269). Dogs that received homeopathic showed 4.49 times more interest in general at D30 than at D1 (P = 0.0214). Animals in the treated group showed an 83% less chance of urinating than the control group in the tests involving displacements. We conclude that the preventive addition of homeopathic medicine containing Natrum muriaticum, Chamomilla, and Ignatia amara reduced undesirable behaviors related to anxiety and increased the incidence of interest behavior.(AU)

Este estudo visou determinar se a formulação homeopática baseada em Natrum muriaticum, Matricaria, Chamomilla, e Ignatia amara foi eficaz para o controle de stress em cães, a fim de prevenir e/ou reduzir a frequência de comportamentos indesejados. Dez cães beagle machos foram divididos em dois grupos, com cinco animais por grupo. O grupo controle recebeu 0,5 mL/dia de placebo via spray na ração durante 30 dias consecutivos, como preventivo. O grupo tratado recebeu 0,5 mL/dia de homeopático via spray na ração durante 30 dias consecutivos, como preventivo. Os testes comportamentais foram realiza-dos em dois momentos, antes e depois de receber o fármaco testado. Foram realizados os seguintes testes comportamentais: a) pessoas conhecidas e desconhecidas no ambiente interno e externo; b) interação com brinquedos; c) interação com um cão desconhecido, d) teste com a guia; e teste com fogos de artifício. Houve um aumento nos comportamentos cavar e escalar a grade no controle (P < 0,05). Os animais que receberam o homeopático sentaram-se 2,54 vezes mais do que o grupo con-trole (P = 0,0269). Os cães que receberam homeopático mostraram 4,49 vezes mais interesse em geral no D30 do que no D1 (P = 0,0214). Os animais do grupo tratado mostraram uma probabilidade 83% menor de urinar do que o grupo controle nos testes envolvendo deslocamento. Concluímos que a adição preventiva de medicamentos homeopáticos contendo Natrum muriaticum, Chamomilla, e Ignatia amara reduziu os comportamentos indesejáveis relacionados com a ansiedade e aumentou a incidência de comportamentos de interesse.(AU)

Aspectos morfofisiológicos e biotécnicas aplicadas à reprodução de novilhas bovinas e búfalas pré-púberes / Morphophysiological aspects and biotechnologies applied to the reproduction of prepubertal bovine and buffalo heifers

A puberdade corresponde ao momento da primeira ovulação, que culmina com o desenvolvimento final dos órgãos e estruturas envolvidas no controle neuro-endócrino reprodutivo. É um fenômeno multifatorial com grande impacto na vida produtiva das futuras matrizes e em sua eficiência econômica, ocorrendo muitas interações entre os fatores internos e externos. A idade da puberdade está relacionada ao peso corporal, que possui grandes efeitos da genética do animal e sua interação com o ambiente, especialmente a nutrição e interação social com machos. Algumas espécies, como os bubalinos, sofrem efeito de outros elementos ambientais, como a luminosidade e o fotoperíodo. A puberdade novilhas búfalas ou bovinas pode ser adiantada por meio do emprego de biotécnicas: indução da puberdade ou inseminação artificial em tempo fixo (IATF). Em ambas, os protocolos baseiam-se, principalmente, em aplicação de progestágeno associado com fonte de estradiol; mas a indução também pode ser realizada utilizando outros hormônios, como hormônio liberador de gonadotrofinas, prostaglandinas e gonadotrofina coriônica equina. No emprego da IATF, novilhas pré-púberes podem ser induzidas e inseminadas com outro protocolo de sincronização ou podem ser inseminadas com o mesmo protocolo de IATF, podendo aumentar as taxas de prenhez e diminuir os custos. Adiantando a puberdade, ocorre incremento na produção, melhorando a eficiência econômica da atividade pecuária.(AU)

Puberty corresponds to the moment of the first ovulation, which culminates in the final development of the organs and structures involved in the neuro-endocrine control of reproduction. It is a multifactorial phenomenon with a great impact on the productive life of future matrices and their economic efficiency, with many interactions between internal and external factors. The age of puberty is related to body weight, which has great effects on the animal's genetics and its interaction with the environment, especially nutrition and social interaction with males. Some species, such as buffalo, are affected by other environmental elements, such as luminosity and photoperiod. Puberty in buffaloes and bovine heifers can be advanced through the use of biotechniques: induction of puberty or timed artificial insemination (TAI). In both, the protocols are mainly based on the application of progestogen associated with a source of estradiol; but induction can also be performed using other hormones, such as gonadotropin-releasing hormone, prostaglandins and equine chorionic gonadotropin. In the employment of the TAI, prepubertal heifers can be induced and inseminated with another synchronization protocol or they can be inseminated with the same TAI protocol, which can increase pregnancy rates and decrease costs. Advancing puberty, there is an increase in production, improving the economic efficiency of livestock activity.(AU)

Effects of environmental enrichment on behavioral expression of pumas (Puma concolor) under human care / Efeitos do enriquecimento ambiental na expressão comportamentalde onças-pardas (Puma concolor) mantidas sob cuidados humanos

The maintenance of pumas under human care imposes different conditions from those found in the natural environment, which may result in stress and impaired welfare. The objective was to evaluate the effects of environmental enrichment on the welfare of four jaguar specimens (Puma concolor), kept under human care. The enrichment techniques addressed were food, sensory, and mixed (physical-cognitive) enrichment. The research was divided into three phases: Phase 1, pre-enrichment; Phase 2, application of enrichment; and Phase 3, post-enrichment. The observation of the activities was performed using the focal animal method, and the behaviors were recorded to compose an ethogram. The sampling effort totaled 96 hours, with a 24-hour observation time for each specimen. During phases 2 and 3, the animals showed increased expression of natural behaviors, increased exploration and interaction with the enclosure, as well as, with other individuals. In addition, the applied activities provided cognitive challenges and reduced the animals' idle time. Although puma 4 showed stereotyped behavior, during the three phases of this study, this individual was healthy and active. Thus, the results demonstrate the beneficial effects of environmental enrichment on the well-being of pumas held in captivity.(AU)

A manutenção de onças-pardas mantidas sob cuidados humanos impõe condições diferentes daquelas encon-tradas no ambiente natural, o que pode resultar em estresse e prejuízo ao bem-estar. Objetivou-se avaliar os efeitos do enriquecimento ambiental no bem-estar de quatro espécimes de Onça-parda (Puma concolor), mantidos sob cuidados humanos. As técnicas de enriquecimento abordadas foram o enriquecimento alimentar, sensorial e misto (físico-cogni-tivo). A pesquisa foi dividida em três fases: Fase 1; Pré-enriquecimento, Fase 2; Aplicação dos enriquecimentos e Fase 3; Pós-enriquecimento. A observação das atividades foi realizada através do método animal focal, sendo registrados os comportamentos para composição de um etograma. O esforço amostral totalizou 96 horas, com o tempo de observação de 24 horas para cada espécime. Durante as fases 2 e 3, os animais apresentaram aumento da expressão de comporta-mentos naturais, aumento da exploração e interação com o recinto, assim como, com os outros indivíduos. Além disso, as atividades aplicadas proporcionaram desafios cognitivos e reduziram o tempo ocioso dos animais. Embora a Onça-parda 4 tenha apresentado comportamento estereotipado, durante as três fases deste estudo, este indivíduo mostrou-se saudável e ativo. Dessa forma, os resultados demonstram os efeitos benéficos do enriquecimento ambiental no bem-estar de onças-pardas mantidas em cativeiro.(AU)

Disfunção cognitiva canina: tratamentos disponíveis / Canine cognitive dysfunction: Available treatments

A disfunção cognitiva canina (DCC) é uma enfermidade que causa alterações fisiológicas e comportamentais em cães idosos, e que apresenta uma fisiopatogenia semelhante à doença de Alzheimer (DA), que acomete seres humanos. Os sinais clínicos são representados pela sigla DISHA (desorientação, mudanças na interação com pessoas/animais, alterações no ciclo sono-vigília, falha no aprendizado/memória e nível de atividades alteradas). A principal forma de diagnóstico da doença é baseada em um questionário respondido pelo tutor, relacionado ao comportamento do animal. O tratamento é multimodal, consistindo basicamente em uso de fármacos, mudanças na alimentação, e enriquecimento ambiental e mental. Os fármacos utilizados são de diversas classes farmacológicas e agem diretamente em substâncias relacionadas com a fisiopatogenia da DCC, além de atenuarem alguns sinais clínicos da enfermidade. Essa ação dos fármacos é potencializada com a adição de alimentos específicos, enriquecimento do ambiente que o animal vive e estimulação mental, principalmente por meio de passeios. A união de todas essas modalidades de tratamento auxilia na melhoria do bem-estar do animal acometido. Como a disfunção não tem cura, o tratamento é longo e, muitas vezes, não é possível visualizar melhora evidente no animal. Dessa forma, alguns tutores acabam optando pela eutanásia. Apesar de ser frequente em cães idosos e haver uma ampla base literária acerca da DCC, não há um protocolo terapêutico específico. Sendo assim, há diversos tratamentos disponibilizados de forma isolada na literatura, fazendo com que os clínicos veterinários encontrem dificuldades para achar um compilado de informações em uma única fonte.

Canine cognitive dysfunction (CCD) is a disease that causes physiological and behavioral changes in elderly dogs and presents a physiopathogeny similar to Alzheimer's disease (AD), which affects humans. Clinical signs are represented by the acronym DISHA (disorientation, changes in interaction with people/animals, changes in the sleep-wake cycle, learning/memory failure, and altered activity level). The main form of diagnosis of illness is based on a questionnaire answered by the tutor, related to the animal behavior. The treatment is multimodal, basically consisting of drug use, changes in the diet, and environmental and mental enrichment. The drugs used are of various pharmacological classes and act directly on substances related to the physiopathogeny of CCD, besides attenuating some clinical signs of the disease. This drug action is enhanced with the addition of specific foods, enrichment of the environment where the animal lives and mental stimulation, mainly through tours. The union of all these treatment modalities helps to improve the welfare of the affected animal. As the disease has no cure, the treatment is long and it is often not possible to visualize evident improvement in the animal. In this way, some tutors opt for euthanasia. Despite being frequent in elderly dogs and there is a broad literature on CCD, there is no specific therapeutic protocol. There are several treatments available in isolation in the literature, causing veterinary clinicians find it difficult to locate a compilation of information from a single source.

Intoxicação de cães por venenos de anuros: prevalência, danos aos animais e protocolos clínicos / Dog poisoning by anuran poisons: prevalence, animal damage and clinical protocols

Indivíduos da família Bufonidae são comumente associados a casos de intoxicação de cães após contato com o veneno secretado nas glândulas presentes no tegumento, reforçando a importância de tratamentos efetivos após esta interação. Neste trabalho apresentamos uma revisão sobre casos de intoxicação de cães por venenos de anuros, relacionando os principais sintomas nos cães e os protocolos clínicos utilizados. Realizamos uma busca por artigos que relatem casos de intoxicação de cães por anuros nos repositórios Google Scholar, Scielo e PubMed. Utilizamos palavras-chave nos idiomas português e inglês. Um total de 430 artigos foram encontrados, sendo apenas 17 de acordo com a proposta da pesquisa. Os registros encontrados foram para o Brasil, Austrália e Estados Unidos. As espécies de anuros reportadas na literatura foram exclusivamente as do gênero Rhinella. O maior número dos casos registrados no Brasil ocorreu em ambiente urbano. Os principais sintomas descritos após intoxicação de cães foram salivação em excesso, convulsão e vômito. Óbitos também foram encontrados durante a busca. Principais protocolos para o tratamento após envenenamento foram lavagem da cavidade oral do cão, e administração de atropina, diazepam e fluidoterapia. Foi observado que há influência do tamanho dos cães na severidade após intoxicação, sendo os de pequeno porte mais suscetíveis a quadros letais. Sugerimos, por conta do baixo número de registros, que possivelmente a quantidade de casos acerca desta temática seja subestimado. Neste estudo evidenciamos que os protocolos utilizados para o cuidado dos cães intoxicados não são realizados de forma padrão, alterando de acordo com o quadro clínico apresentado.

Individuals of the Bufonidae family are commonly associated with cases of poisoning in dogs after contact with the venom secreted in glands present in the tegument, reinforcing the importance of effective treatments after this interaction. In this paper, we present a review of cases of poisoning in dogs by anuran venom, relating the main symptoms in dogs and the clinical protocols used. We performed a search for articles reporting cases of anuran poisoning in dogs in the Google Scholar, Scielo, and PubMed repositories. We used keywords in Portuguese and English. A total of 430 articles were found and only 17 of which were in accordance with the research proposal. The records found were for Brazil, Australia, and the United States. The species of anurans reported in the literature were exclusively those of the genus Rhinella. The greatest number of cases registered in Brazil occurred in an urban environment. The main symptoms described after intoxication in dogs were excessive salivation, convulsion, and vomiting. Deaths were also found during the search. The main protocols for treatment after poisoning were washing the dog's oral cavity, and administration of atropine, diazepam, and fluid therapy. It was observed that the size of the dogs influences the severity after intoxication, with small dogs being more susceptible to lethal conditions. Due to the low number of records, we suggest that the number of cases on this topic is possibly underestimated. In this study, we showed that the protocols used for the care of intoxicated dogs are not performed in a standard way, changing according to the clinical picture presented.

Testing spatial and environmental factors to explain body shape variation in the widespread Central American Blackbelt cichlid Vieja maculicauda (Teleostei: Cichlidae)

Body-shape variability may respond to the interaction between history and environment, particularly in species whose range includes known biogeographical barriers. Central America has traditionally been regarded to have functioned as a complete land-bridge connecting two continents since the Plio-Pleistocene and as an incomplete one since much earlier. This history has helped shape species diversification and distributions. Vieja maculicauda is a widely distributed cichlid, found throughout most of the Atlantic slope of Central America, across three of the four geological blocks that make up this region and whose borders are known dispersal barriers. We asked whether there is an effect of geologic blocks on body shape of V. maculicauda as determined by geometric morphometric assessment of 151 individuals from across its range. We asked how much variance in body shape is explained by environmental variables. We used a CVA and a MANCOVA to determine whether a relationship between body shape and geologic blocks exists. For testing body shape correlation against geographic and environmental variables, we used a Mantel test. Our results suggest that body shape in V. maculicauda can be segregated by geologic blocks, while the correlation results showed no strong correlation between our sets of variables.(AU)

La variabilidad en forma de cuerpo puede responder a la interacción entre historia y medio ambiente, particularmente en especies de amplia distribución cuyo rango incluya barreras biogeográficas conocidas. Tradicionalmente se ha considerado que Centroamérica ha funcionado como un puente terrestre conectando dos masas continentales desde alrededor del Plio-Pleistoceno y como un puente incompleto desde mucho antes. Esta historia ha ayudado a moldear la diversificación y distribución de especies. Vieja maculicauda es un cíclido de amplia distribución, encontrado a través de la mayor parte de la vertiente Atlántica de Centroamérica, en tres de los cuatro bloques que componen la región y cuyas fronteras son bien conocidas como barreras de dispersión. Nos preguntamos si hay un efecto del bloque geológico en la forma de cuerpo de V. maculicauda, determinado a través de una evaluación de morfometría geométrica de 151 especímenes a lo largo de su distribución. También nos preguntamos cuánta varianza en la forma de cuerpo es explicada por variables ambientales. Utilizamos un AVC y un MANCOVA para determinar si existe una relación entre forma de cuerpo y bloque geológico. Para probar las correlaciones de la forma de cuerpo con variables geográficas y medioambientales utilizamos una prueba de Mantel. Nuestros resultados sugieren que la forma de cuerpo en Vieja maculicauda puede ser segregada por bloque geológico, mientras que los resultados de la correlación no mostraron una correlación fuerte entre nuestros sets de variables.(AU)

Yield and nutritional value of sorghum genotype silages using Azospirillum brasilense in the northern region of the state of Minas Gerais / Produtividade e valor nutricional das silagens de genótipos de sorgo com uso de Azospirillum brasilense na região norte de Minas Gerais

Sorghum is a crop of great interest in animal feed in semiarid regions. The environment and nitrogen fertilization can influence its productive potential and nutritional quality. This study aimed to evaluate sorghum biomass genotypes associated or not with Azospirillum brasilense managed at different sowing sites on the yield and nutritional value of silage. We evaluated 3 sorghum genotypes combined with 3 fertilization strategies using urea, Azospirillum brasilense and the urea/A brasilense combination in two planting sites (Janaúba, MG, and Montes Claros, MG). A randomized block design was carried out in a 3 x 3 x 2 factorial arrangement of 3 genotypes, 3 fertilization strategies and 2 sowing sites. Azospirillum brasilense foliar spraying was carried out using a costal (Backpack) atomizer and for silage production, PVC silos with weight and length of 50 cm and 10 cm in diameter were used. There was no triple interaction between the studied variables. There were differences between genotypes and between sites for agronomic traits. Statistical differences were detected between genotypes and sites for chemical composition, and sorghum forage on digestibility evaluations. The region of Montes Claros has greater forage production and the region of Janaúba has better quality of silage. Biomass sorghum genotypes have higher forage production and the Volumax genotype has better silage quality(AU)

O sorgo é uma cultura de grande interesse na alimentação animal em regiões semiáridas. O ambiente e a adubação nitrogenada podem influenciar seu potencial produtivo e qualidade nutricional. Este trabalho teve como objetivo avaliar genótipos de biomassa de sorgo associados ou não ao Azospirillum brasilense manejados em diferentes locais de semeadura sobre a produtividade e valor nutricional da silagem. Foram avaliados três genótipos de sorgo associados e três estratégias de adubação utilizando ureia, Azospirillum brasilense e a associação ureia/A. brasilense em dois locais de plantio (Janaúba, MG e Montes Claros, MG). O delineamento foi em blocos casualizados em esquema fatorial 3 x 3 x 2, com 3 genótipos, 3 estratégias de adubação e 2 locais de semeadura. A pulverização foliar de Azospirillum brasilense foi feita com o auxílio de um atomizador costal e para a produção de silagem foram utilizados silos de PVC com peso conhecido e comprimento de 50 cm e 10 cm de diâmetro. Não houve interação tripla entre as variáveis estudadas. Houve diferenças entre genótipos e entre locais para características agronômicas. Também foram observadas diferenças estatísticas entre os genótipos e locais estudados para a composição química e forrageira de sorgo nas avaliações de digestibilidade. A região de Montes Claros possui maior produção de forragem e a região de Janaúba possui melhor qualidade de silagem. Os genótipos de sorgo biomassa apresentam maior produção de forragem e o genótipo Volumax apresenta melhor qualidade de silagem.(AU)

Two new species of monogenoidean parasites (Platyhelminthes: Neodermata) of ornamental fish of Loricariidae (Siluriformes) from the Xingu River, Brazilian Amazon

Two new monogenoidean species of Unilatus Mizelle & Kritsky, 1967 found in the gills of loricariids in the Lower Xingu-Iriri rivers are described: Unilatus humboldtii sp. nov. from Baryancistrus niveatus (Castelnau, 1855), Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010, Pseudacanthicus sp. (type-host), and Scobinancistrus aureatus Burgess, 1994; and Unilatus luciarappae sp. nov. from P. armbrusteri. Unilatus humboldtii sp. nov. is distinguished from other congeneric species due to its anterior anchor with well-developed superficial root with depressed or truncated distal portion, and inconspicuous or reduced deep root; anterior bar with posteromedial projection; hooks of pair 1 with dilated shaft comprising 2/3 of the hook length; spiraled male copulatory organ with approximately 16-18 counterclockwise loops. Unilatus luciarappae sp. nov. is characterized by having anterior anchor with well-developed superficial root and reduced deep root, slightly curved shaft, elongated, slightly curved, and tapered point; spiraled MCO with approximately 18-19 counterclockwise loops, with median distal bulbous portion and remaining portion tapered and elongated, comprising 1/4 of the body length; and accessory piece comprising approximately 2/3 of the MCO length. More than fifty years after the description of the type species of Unilatus from an artificial environment (U.S. aquaria), this study represents the first formal record and description of Unilatus species from hosts collected in natural habitats in the Xingu River. Considering the impact of the Belo Monte dam on the formerly pristine conditions of the study region and the importance of loricariids for the ornamental fish trade, we recommend monitoring monogenoidean diversity, parasite-host interaction, as well as the dispersion patterns and pathogenicity of these parasites.(AU)

Ingestive behavior and infrared thermography of Holstein × Zebu crossbreed cows in the final third of gestation in different pastoral environments

This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)

Ingestive behavior and infrared thermography of Holstein × Zebu crossbreed cows in the final third of gestation in different pastoral environments

This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)