RESUMO
Rhipicephalus (Boophilus) microplus is one of the parasites that has an impact on livestock farming in Brazil. Bioassays using the larval packet test (LPT) impregnated with cypermethrin and diazinon at different concentrations were performed to characterize phenotypic resistance (resistance level, RL), molecular resistance (mutation in domain III - S6 T2134A) and enzymatic metabolism of diazinon and cypermethrin in some populations of R. microplus that were collected in different regions of the state of São Paulo. Among the 40 farms analyzed, 18 of them presented resistance factors for cypermethrin, with RL I (53%) and RL II (47%). Mutation of domain III T2134A was found for the first time in Brazil, on seven farms. Heterozygous larvae were found on six of them and resistant homozygous larvae on four. No differences (p>0.05) in enzymatic activity of α-esterase and ß-esterase were found in tests with live and dead larvae at a cypermethrin concentration of 409.6µg/cm2. Ninety percent of the farms showed resistance to the active agent diazinon: RL I in 6%, RL II in 30% and RL III in 64%. There were significant differences (p<0.05) in enzymatic activity at the highest concentration (3.2µg/cm2).
Rhipicephalus (Boophilus) microplus (Canestrini) é um dos parasitas que mais impactam a pecuária de países tropicais e subtropicais, incluindo o Brasil, com perdas em torno de US$ 3,24 bilhões por ano. Ocorrências de populações resistentes a diferentes classes de acaricidas e suas associações têm sido amplamente diagnosticadas em todo o Brasil. Para isso, bioensaios utilizando o teste de pacote larval (LPT) impregnado com cipermetrina e diazinon em diferentes concentrações foram realizados para caracterizar a resistência fenotípica (nível de resistência, RL), a resistência molecular (mutação no domínio III - S6 T2134A) e o metabolismo enzimático do diazinon e da cipermetrina em algumas populações de R. (Boophilus) microplus coletadas em diferentes regiões do estado de São Paulo. Dentre as 40 propriedades analisadas, 18 delas apresentaram fatores de resistência à cipermetrina, sendo RL I (53%) e RL II (47%). A mutação do domínio III T2134A foi encontrada pela primeira vez no Brasil, em sete fazendas. Larvas heterozigotas foram constatadas em seis delas, e larvas homozigotas resistentes em quatro. Nenhuma diferença (P>0,05) na atividade enzimática de α-esterase e ß-esterase foi observada em testes com larvas vivas e mortas em uma concentração de cipermetrina de 409,6µg/cm2. Noventa por cento das propriedades apresentaram resistência ao agente ativo diazinon: RL I em 6%, RL II em 30% e RL III em 64%. Houve diferenças significativas (P<0,05) na atividade enzimática na concentração mais elevada (3,2µg/cm2) entre os grupos de larvas vivas e mortas.
Assuntos
Animais , Rhipicephalus , Diazinon , AcaricidasRESUMO
We assessed the impact of genetic divergence and the ability to combine corn hybrids used for the production of silage on the agronomic and bromatological traits of silage quality. We evaluated 18 corn hybrids used as genitors in a circulant diallel scheme in which each genitor hybrid participated in 9 hybrid combinations, and evaluated 100 treatments [18 genitor hybrids, 81 diallelic hybrids, and a commercial check hybrid (DKB330)] in a triple lattice 10 x 10 experimental design in two environments in Brazil. Genetic variability was adequate among the corn silage hybrids, and we can recommend the use of genitors 2B688 and P30B39 for the formation of a base population for intrapopulational breeding. The P30P34 hybrid is the best for intrapopulational breeding when aiming for silage with high protein content, low fiber content, and higher in vitro digestibility. Interpopulational breeding directed at improving silage digestibility can use a combination of genitors P30P34 and AS1572, but AS1572 and P30K64 are the most recommended. Hybrids 2B688, P30P34, and SG6015 are considered the most genetically distant of the others hybrids, and have desirable combining potential; therefore, they are important genitors for the formation of new segregated populations for improving corn silage.
Assuntos
Variação Genética , Hibridização Genética , Silagem/normas , Zea mays/genética , Melhoramento Vegetal/métodos , Característica Quantitativa HerdávelRESUMO
In this study, we evaluated the fungicide effect on the incidence of rot grains and expression of catalase (CAT), alcohol dehydrogenase (ADH), and malate dehydrogenase (MDH) enzymes in commercial maize hybrids grown with conventional and reduced spacing in Guarapuava, PR, Brazil. The experiment was designed in random blocks with a 3 × 8-factorial scheme, totaling 24 treatments. The first factor constituted three levels, the first with foliar fungicide application [150.0 g/L trifloxystrobin (15.0%, w/v) + 175.0 g/L prothioconazole (17.5%, w/v)] at a dose of 0.4 L/ha at V8-stage eight expanded leaves and the second with an application of 0.5 L/ha at VT-tasseling and check (no fungicide application) stage. The second factor comprised eight maize hybrids that were divided into two groups, complex (AG 9045PRO, AG 8041PRO, DKB245PRO2, and 2B707PW) and susceptible (P 32R48H, DKB390PRO, P 30F53H, and P 30R50H), according to their reaction to the causative fungus, totaling 72 plots at each site in the crop of 2013/2014. The percentage of rot grains and the expression of CAT, ADH, and MDH were evaluated for each hybrid. The percentage of rot grains was influenced by the hybrid and fungicide used. The (trifloxystrobin + prothioconazole) reduced the incidence of rot grains, with relatively higher reduction in the hybrids considered susceptible. The higher expression of CAT enzyme was related to the higher incidence of rot grains because of grain deterioration, depending on the hybrids evaluated. A higher expression of ADH and MDH enzymes was observed in the maize hybrids belonging to the group considered tolerant.
Assuntos
Álcool Desidrogenase/genética , Antifúngicos/farmacologia , Catalase/genética , Malato Desidrogenase/genética , Proteínas de Plantas/genética , Zea mays/efeitos dos fármacos , Acetatos/farmacologia , Álcool Desidrogenase/metabolismo , Catalase/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Iminas/farmacologia , Malato Desidrogenase/metabolismo , Metacrilatos/farmacologia , Proteínas de Plantas/metabolismo , Sementes/efeitos dos fármacos , Sementes/enzimologia , Sementes/genética , Sementes/microbiologia , Estrobilurinas , Triazóis/farmacologia , Zea mays/enzimologia , Zea mays/genética , Zea mays/microbiologiaRESUMO
Caracterizaram-se as agressões por cães, o perfil das vítimas e dos agressores e as circunstâncias desses acidentes. Calculou-se a amostra aleatória a partir de 20 mil notificações/ano de agressões por cães e realizaram-se 594 entrevistas telefônicas. A maior frequência de agressões ocorreu no sexo masculino, faixa etária de cinco a 14 anos. Lesões leves representaram 80,4%. As profundas (19,1%) ocorreram por cães de porte médio seguidas pelos de grande porte. A maioria dos cães era macho adulto, porte médio. Dos entrevistados, 52,5% desconheciam a condição reprodutiva; 41,0% dos cães não eram esterilizados e 6,4% eram esterilizados. Cães sem raça definida (SRD) provocaram 48,4% dos acidentes, e 57,6% das agressões ocorreram em locais privados. Em 56,2% das agressões, as vítimas eram moradoras do imóvel ou pessoas conhecidas. Com animais não conhecidos a agressão mais frequente ocorreu na rua, 30,8%, e 67,5% dos donos permaneceram com os animais. As agressões foram resultantes da interação homem-cão e devem ser estudadas para se identificarem os possíveis comportamentos que desencadeiam a agressão pelo animal.
This study aimed to characterize aggression by dogs, the profile of victims, and perpetrators and circumstances of these accidents. Understanding the interaction between victims and aggressive dogs contributes to preventing aggression. The random sample from 20.000 reports / year of attacks by dogs was calculated and 594 telephone interviews were conducted. The highest frequency of assaults occurred in males from 5 to 14 years of age. Non-severe injuries represented 80.4%. Deep lesions (19.1%) were caused by medium and large dogs. Most dogs were medium size adult males. Of the respondents, 52.5% were unaware of the reproductive condition, 41.0% of dogs were not sterilized and 6.4% were sterilized. Dogs without defined race caused 48.4% of accidents and 57.6% of assaults occurred in private places. In 56.2% assault victims were residents of the property or known people. Aggressions from unknown animals were more frequent on the street (30.8%). 67.5% remained with the animals' owners. The attacks were the result of interaction between man and dog and should be studied to identify which human and canine behaviors can trigger accidents, to understand how the interaction occurs in different situations whithin the same household, with acquaintances, on the street, and with unknown animals. Educational approaches detailing risks and prevention methods are essential.
Assuntos
Animais , Cães , Agressão , Comportamento Animal , Saúde Pública , Cães/classificaçãoRESUMO
Caracterizaram-se as agressões por cães, o perfil das vítimas e dos agressores e as circunstâncias desses acidentes. Calculou-se a amostra aleatória a partir de 20 mil notificações/ano de agressões por cães e realizaram-se 594 entrevistas telefônicas. A maior frequência de agressões ocorreu no sexo masculino, faixa etária de cinco a 14 anos. Lesões leves representaram 80,4%. As profundas (19,1%) ocorreram por cães de porte médio seguidas pelos de grande porte. A maioria dos cães era macho adulto, porte médio. Dos entrevistados, 52,5% desconheciam a condição reprodutiva; 41,0% dos cães não eram esterilizados e 6,4% eram esterilizados. Cães sem raça definida (SRD) provocaram 48,4% dos acidentes, e 57,6% das agressões ocorreram em locais privados. Em 56,2% das agressões, as vítimas eram moradoras do imóvel ou pessoas conhecidas. Com animais não conhecidos a agressão mais frequente ocorreu na rua, 30,8%, e 67,5% dos donos permaneceram com os animais. As agressões foram resultantes da interação homem-cão e devem ser estudadas para se identificarem os possíveis comportamentos que desencadeiam a agressão pelo animal.(AU)
This study aimed to characterize aggression by dogs, the profile of victims, and perpetrators and circumstances of these accidents. Understanding the interaction between victims and aggressive dogs contributes to preventing aggression. The random sample from 20.000 reports / year of attacks by dogs was calculated and 594 telephone interviews were conducted. The highest frequency of assaults occurred in males from 5 to 14 years of age. Non-severe injuries represented 80.4%. Deep lesions (19.1%) were caused by medium and large dogs. Most dogs were medium size adult males. Of the respondents, 52.5% were unaware of the reproductive condition, 41.0% of dogs were not sterilized and 6.4% were sterilized. Dogs without defined race caused 48.4% of accidents and 57.6% of assaults occurred in private places. In 56.2% assault victims were residents of the property or known people. Aggressions from unknown animals were more frequent on the street (30.8%). 67.5% remained with the animals' owners. The attacks were the result of interaction between man and dog and should be studied to identify which human and canine behaviors can trigger accidents, to understand how the interaction occurs in different situations whithin the same household, with acquaintances, on the street, and with unknown animals. Educational approaches detailing risks and prevention methods are essential.(AU)
Assuntos
Humanos , Animais , Masculino , Feminino , Vigilância em Desastres , Causalidade , Saúde PúblicaRESUMO
Caracterizaram-se as agressões por cães, o perfil das vítimas e dos agressores e as circunstâncias desses acidentes. Calculou-se a amostra aleatória a partir de 20 mil notificações/ano de agressões por cães e realizaram-se 594 entrevistas telefônicas. A maior frequência de agressões ocorreu no sexo masculino, faixa etária de cinco a 14 anos. Lesões leves representaram 80,4%. As profundas (19,1%) ocorreram por cães de porte médio seguidas pelos de grande porte. A maioria dos cães era macho adulto, porte médio. Dos entrevistados, 52,5% desconheciam a condição reprodutiva; 41,0% dos cães não eram esterilizados e 6,4% eram esterilizados. Cães sem raça definida (SRD) provocaram 48,4% dos acidentes, e 57,6% das agressões ocorreram em locais privados. Em 56,2% das agressões, as vítimas eram moradoras do imóvel ou pessoas conhecidas. Com animais não conhecidos a agressão mais frequente ocorreu na rua, 30,8%, e 67,5% dos donos permaneceram com os animais. As agressões foram resultantes da interação homem-cão e devem ser estudadas para se identificarem os possíveis comportamentos que desencadeiam a agressão pelo animal.(AU)
This study aimed to characterize aggression by dogs, the profile of victims, and perpetrators and circumstances of these accidents. Understanding the interaction between victims and aggressive dogs contributes to preventing aggression. The random sample from 20.000 reports / year of attacks by dogs was calculated and 594 telephone interviews were conducted. The highest frequency of assaults occurred in males from 5 to 14 years of age. Non-severe injuries represented 80.4%. Deep lesions (19.1%) were caused by medium and large dogs. Most dogs were medium size adult males. Of the respondents, 52.5% were unaware of the reproductive condition, 41.0% of dogs were not sterilized and 6.4% were sterilized. Dogs without defined race caused 48.4% of accidents and 57.6% of assaults occurred in private places. In 56.2% assault victims were residents of the property or known people. Aggressions from unknown animals were more frequent on the street (30.8%). 67.5% remained with the animals' owners. The attacks were the result of interaction between man and dog and should be studied to identify which human and canine behaviors can trigger accidents, to understand how the interaction occurs in different situations whithin the same household, with acquaintances, on the street, and with unknown animals. Educational approaches detailing risks and prevention methods are essential.(AU)
Assuntos
Animais , Cães , Comportamento Animal , Saúde Pública , Agressão , Cães/classificaçãoRESUMO
Acaricide resistance of the cattle tick Rhipicephalus (Boophilus) microplus is widespread in most of the countries where this parasite is present. Bioassays are used to diagnose the level and pattern of resistance in tick populations. In the present study, we describe a detailed protocol of the Larval Tarsal Test (LTT) using simplified equipment and data on the resistance of 17 tick field populations originating from 5 Brazilian states. Nine acaricidal compounds from 5 major classes were tested: organophosphates (OP), synthetic pyrethroids (SP), macrocyclic lactones (ML), phenylpyrazols (PYZ) and amidines. For comparison, four of the tick populations were also tested with the Larval Packet Test (LPT) with one compound per class. The most common resistances were to SP, amitraz and OP, with frequencies of 94%, 88% and 82%, respectively. Resistance to PYZ was also found to be widespread (65%), suggesting a rapid development of fipronil resistance in Brazil. One case of ML resistance and 2 cases of suspected ML resistance were identified with the LTT. The LTT led to higher resistance ratios to all compounds than the LPT, reflecting its high sensitivity to detect resistance. Finally, the LTT allowed testing a larger number of compounds and doses with reduced labour in comparison to the LPT and turned out to be a reliable bioassay to detect resistance in field populations.
Assuntos
Acaricidas/farmacologia , Rhipicephalus/efeitos dos fármacos , Animais , Brasil , Resistência a Inseticidas , Larva/efeitos dos fármacos , Dose Letal Mediana , Análise de SobrevidaRESUMO
A caracterização das populações canina e felina domiciliadas do município de São Paulo (SP) foi realizada utilizando-se amostragem complexa com seleção aleatória em dois estágios. Em cada distrito administrativo, foram visitados seis setores censitários e 20 domicílios em cada setor sorteado, de setembro de 2006 a setembro de 2009, totalizando 11.272 entrevistas. A razão homem:cão foi de 4,34, e a razão homem:gato de 19,33. A população canina foi estimada em 2.507.401, e a felina em 562.965. A população canina era composta por 52,7% de machos, e a felina por 45,1%. A proporção de fêmeas esterilizadas, 23,4% das cadelas e 46,1% das gatas, é maior que a de machos, 11,4% dos cães e 31,5% dos gatos. A idade média dos cães era de 4,99 anos e a dos gatos de 3,53 anos. A proporção de cães com restrição de acesso à rua, 64,4%, foi maior que a de gatos, 42,5%. A média de animais/domicílio foi estimada em 1,60 para cães e 1,69 para gatos. A guarda destes animais está associada a fatores culturais, assim a caracterização da população de animais é base da estruturação adequada de programas de controle populacional e de zoonoses.
This study aimed to estimate the owned dog and cat populations of São Paulo city using a complex sample with random selection in two stages. In each administrative district, six census sectors and 20 households in each sampled sector were visited from September 2006 to September 2009, totalizing 11,272 interviews. The human:dog ratio was 4.34 and the human:cat ratio was 19.33. The dog population was 2,507,401 and the cat population, 562,965. The dog population was composted of 52.7% males, while among the cat population it was 45.1%. The proportion of sterilized females (23.4% among dogs and 46.1% among cats) was higher than males (11.4% among dogs and 31.5% among cats). The mean age of dogs was 4.99 years, and for cats, 3.53 years. The proportion of restricted (without access to the street) dogs, 64.4%, was higher than restricted cats, 42.5%. The average number of animals/household was 1.60 for dogs and 1.69 for cats. The animal ownership is associated with cultural factors, therefore the characterization of canine and feline population is essential to implement an adequate animal population management program and zoonosis control.
Assuntos
Animais , Gatos , Cães , Castração/veterinária , Zoonoses , Castração/estatística & dados numéricos , Castração/tendênciasRESUMO
The applicability of laboratory bioassays to diagnose ivermectin (IVM) resistance in Rhipicephalus microplus was evaluated. Adult immersion tests (AITs), larval immersion tests (LITs) and larval packet tests (LPTs) were performed to characterise the effects of ivermectin toxicity on adults and larvae of a susceptible reference strain. The AIT was determined to be a reasonable assay but requires a large number of individuals to attain interpretable results. The LIT and LPT were validated with an IVM resistant strain, revealing resistance ratios (RRs) of 6.73 and 1.49, respectively. In a field survey, nine different populations of cattle tick from the states of São Paulo and Mato Grosso do Sul, Brazil, were analysed with the LIT. Populations without previous exposure to ivermectin exhibited RRs between 0.87 and 1.01. Populations previously exposed to IVM showed RRs between 1.83 and 4.62. The LIT was more effective at discriminating between resistant and susceptible populations than the LPT. The use of the LIT is recommended for the diagnosis of ivermectin resistance in R. microplus.
Assuntos
Antiparasitários/farmacologia , Bioensaio/normas , Resistência a Medicamentos , Ivermectina/farmacologia , Rhipicephalus/efeitos dos fármacos , Animais , Brasil , Feminino , Larva/efeitos dos fármacos , Dose Letal Mediana , Reprodutibilidade dos TestesRESUMO
Rhipicephalus (Boophilus) microplus tick is one of the most important parasite afflicting cattle, mainly in taurine breed. Chemical application is still the most widely used way of control, although there are reports of tick resisting to many active principles in different countries. The goal of this study was to obtain the in vitro sensitivity profile of dairy cattle ticks to six commercial acaricides in five small farms in northwestern São Paulo state, located in Bady Bassitt and Ipiguá municipalities, and to investigate the productive characteristics and tick control methods applied in these farms. R. (B.) microplus engorged females were collected from naturally infested cattle and subjected to adult immersion test using the following drugs: amitraz, cypermethrin, deltamethrin, chlorpyrifos/cypermethrin mix, dichlorvos/cypermethrin mix, and dichlorvos/chlorpyrifos mix. In each farm, a questionnaire was also administered. Considering the mean efficacy level from all farms, there was no product with appropriate efficacy level. Pyrethroids had the worst results (cypermethrin and deltamethrin having mean efficacy of 17% and 27% respectively), with resistance observed in all farms. Conversely, amitraz (73%), chlorpyrifos/cypermethrin (79%), and chlorpyrifos/dichlorvos (76%) exhibited the highest mean efficacies. The ticks were resistant to all formulations in two herds. The cattle farmers were not aware of tests that detect ticks susceptibility to acaricides and did not adopt proper technical procedure when using chemicals. These indicate the need to educate cattle farmers on considering resistance as a product choice criterion. A constant monitoring of resistance is also relevant. Further investigations in the region should be conducted to better understand the resistance levels.
O carrapato Rhipicephalus (Boophilus) microplus é um dos parasitos mais importantes em bovinos, principalmente nos de raça taurina. O controle químico ainda é a forma mais utilizada para o seu controle, porém, há relatos de resistência dos carrapatos a vários princípios ativos em diversos países. O presente trabalho objetivou obter o perfil de sensibilidade in vitro de carrapatos de bovinos leiteiros a seis carrapaticidas comerciais em cinco propriedades do noroeste paulista, localizadas nos municípios de Bady Bassitt e Ipiguá, além de investigar as características produtivas e métodos de controle de carrapatos empregados nestas propriedades. Fêmeas ingurgitadas de R. (B.) microplus foram coletadas de bovinos naturalmente infestados e submetidas ao teste de imersão de adultas frente aos seguintes princípios ativos: amitraz, cipermetrina, deltametrina, associação clorpirifós/cipermetrina, associação diclorvós/cipermetrina e associação diclorvós/clorpirifós. Em cada propriedade, também foi aplicado um questionário. Considerando-se a eficácia média entre todas as propriedades, nenhum produto mostrou eficácia desejável. Os piretroides obtiveram os piores resultados (eficácias médias de 17% e 27%, respectivamente, para cipermetrina e deltametrina), sendo que em todas as propriedades havia resistência. Já amitraz (73%), clorpirifós/cipermetrina (79%) e clorpirifós/diclorvós (76%) mostraram as maiores eficácias médias. Em dois rebanhos os carrapatos foram resistentes a todas as formulações. Os produtores não conheciam o biocarrapaticidograma e aplicavam carrapaticidas sem critério técnico. Os resultados mostram a necessidade de orientação aos produtores quanto à utilização do biocarrapaticidograma como critério para escolha do acaricida. Um monitoramento constante da resistência também é relevante. Outros estudos na região devem ser feitos para melhor caracterização do nível de resistência.
RESUMO
A caracterização das populações canina e felina domiciliadas do município de São Paulo (SP) foi realizada utilizando-se amostragem complexa com seleção aleatória em dois estágios. Em cada distrito administrativo, foram visitados seis setores censitários e 20 domicílios em cada setor sorteado, de setembro de 2006 a setembro de 2009, totalizando 11.272 entrevistas. A razão homem:cão foi de 4,34, e a razão homem:gato de 19,33. A população canina foi estimada em 2.507.401, e a felina em 562.965. A população canina era composta por 52,7% de machos, e a felina por 45,1%. A proporção de fêmeas esterilizadas, 23,4% das cadelas e 46,1% das gatas, é maior que a de machos, 11,4% dos cães e 31,5% dos gatos. A idade média dos cães era de 4,99 anos e a dos gatos de 3,53 anos. A proporção de cães com restrição de acesso à rua, 64,4%, foi maior que a de gatos, 42,5%. A média de animais/domicílio foi estimada em 1,60 para cães e 1,69 para gatos. A guarda destes animais está associada a fatores culturais, assim a caracterização da população de animais é base da estruturação adequada de programas de controle populacional e de zoonoses.(AU)
This study aimed to estimate the owned dog and cat populations of São Paulo city using a complex sample with random selection in two stages. In each administrative district, six census sectors and 20 households in each sampled sector were visited from September 2006 to September 2009, totalizing 11,272 interviews. The human:dog ratio was 4.34 and the human:cat ratio was 19.33. The dog population was 2,507,401 and the cat population, 562,965. The dog population was composted of 52.7% males, while among the cat population it was 45.1%. The proportion of sterilized females (23.4% among dogs and 46.1% among cats) was higher than males (11.4% among dogs and 31.5% among cats). The mean age of dogs was 4.99 years, and for cats, 3.53 years. The proportion of restricted (without access to the street) dogs, 64.4%, was higher than restricted cats, 42.5%. The average number of animals/household was 1.60 for dogs and 1.69 for cats. The animal ownership is associated with cultural factors, therefore the characterization of canine and feline population is essential to implement an adequate animal population management program and zoonosis control.(AU)
Assuntos
Animais , Gatos , Cães , Zoonoses , Castração/veterinária , Castração/estatística & dados numéricos , Castração/tendênciasRESUMO
Rhipicephalus (Boophilus) microplus tick is one of the most important parasite afflicting cattle, mainly in taurine breed. Chemical application is still the most widely used way of control, although there are reports of tick resisting to many active principles in different countries. The goal of this study was to obtain the in vitro sensitivity profile of dairy cattle ticks to six commercial acaricides in five small farms in northwestern São Paulo state, located in Bady Bassitt and Ipiguá municipalities, and to investigate the productive characteristics and tick control methods applied in these farms. R. (B.) microplus engorged females were collected from naturally infested cattle and subjected to adult immersion test using the following drugs: amitraz, cypermethrin, deltamethrin, chlorpyrifos/cypermethrin mix, dichlorvos/cypermethrin mix, and dichlorvos/chlorpyrifos mix. In each farm, a questionnaire was also administered. Considering the mean efficacy level from all farms, there was no product with appropriate efficacy level. Pyrethroids had the worst results (cypermethrin and deltamethrin having mean efficacy of 17% and 27% respectively), with resistance observed in all farms. Conversely, amitraz (73%), chlorpyrifos/cypermethrin (79%), and chlorpyrifos/dichlorvos (76%) exhibited the highest mean efficacies. The ticks were resistant to all formulations in two herds. The cattle farmers were not aware of tests that detect ticks susceptibility to acaricides and did not adopt proper technical procedure when using chemicals. These indicate the need to educate cattle farmers on considering resistance as a product choice criterion. A constant monitoring of resistance is also relevant. Further investigations in the region should be conducted to better understand the resistance levels.(AU)
O carrapato Rhipicephalus (Boophilus) microplus é um dos parasitos mais importantes em bovinos, principalmente nos de raça taurina. O controle químico ainda é a forma mais utilizada para o seu controle, porém, há relatos de resistência dos carrapato a vários princípios ativos em diversos países. O presente trabalho objetivou obter o perfil de sensibilidade in vitro de carrapatos de bovinos leiteiros a seis carrapaticidas comerciais em cinco propriedades do noroeste paulista, localizadas nos municípios de Bady Bassitt e Ipiguá, além de investigar as características produtivas e métodos de controle de carrapatos empregados nestas propriedades. Fêmeas ingurgitadas de R. (B.) microplus foram coletadas de bovinos naturalmente infestados e submetidas ao teste de imersão de adultas frente aos seguintes princípios ativos: amitraz, cipermetrina, deltametrina, associação clorpirifós/cipermetrina, associação diclorvós/cipermetrina e associação diclorvós/clorpirifós. Em cada propriedade, também foi aplicado um questionário. Considerando-se a eficácia média entre todas as propriedades, nenhum produto mostrou eficácia desejável. Os piretroides obtiveram os piores resultados (eficácias médias de 17% e 27%, respectivamente, para cipermetrina e deltametrina), sendo que em todas as propriedades havia resistência. Já amitraz (73%), clorpirifós/cipermetrina (79%) e clorpirifós/diclorvós (76%) mostraram as maiores eficácias médias. Em dois rebanhos os carrapatos foram resistentes a todas as formulações. Os produtores não conheciam o biocarrapaticidograma e aplicavam carrapaticidas sem critério técnico. Os resultados mostram a necessidade de orientação aos produtores quanto à utilização do biocarrapaticidograma como critério para escolha do acaricida. Um monitoramento constante da resistência também é relevante. Outros estudos na região devem ser feitos para melhor caracterização do nível de resistência.(AU)
Assuntos
Animais , Carrapatos/classificação , Acaricidas/farmacologia , Bovinos/classificação , Rhipicephalus/classificaçãoRESUMO
Rhipicephalus (Boophilus) microplus tick is one of the most important parasite afflicting cattle, mainly in taurine breed. Chemical application is still the most widely used way of control, although there are reports of tick resisting to many active principles in different countries. The goal of this study was to obtain the in vitro sensitivity profile of dairy cattle ticks to six commercial acaricides in five small farms in northwestern São Paulo state, located in Bady Bassitt and Ipiguá municipalities, and to investigate the productive characteristics and tick control methods applied in these farms. R. (B.) microplus engorged females were collected from naturally infested cattle and subjected to adult immersion test using the following drugs: amitraz, cypermethrin, deltamethrin, chlorpyrifos/cypermethrin mix, dichlorvos/cypermethrin mix, and dichlorvos/chlorpyrifos mix. In each farm, a questionnaire was also administered. Considering the mean efficacy level from all farms, there was no product with appropriate efficacy level. Pyrethroids had the worst results (cypermethrin and deltamethrin having mean efficacy of 17% and 27% respectively), with resistance observed in all farms. Conversely, amitraz (73%), chlorpyrifos/cypermethrin (79%), and chlorpyrifos/dichlorvos (76%) exhibited the highest mean efficacies. The ticks were resistant to all formulations in two herds. The cattle farmers were not aware of tests that detect ticks susceptibility to acaricides and did not adopt proper technical procedure when using chemicals. These indicate the need to educate cattle farmers on considering resistance as a product choice criterion. A constant monitoring of resistance is also relevant. Further investigations in the region should be conducted to better understand the resistance levels.
O carrapato Rhipicephalus (Boophilus) microplus é um dos parasitos mais importantes em bovinos, principalmente nos de raça taurina. O controle químico ainda é a forma mais utilizada para o seu controle, porém, há relatos de resistência dos carrapato a vários princípios ativos em diversos países. O presente trabalho objetivou obter o perfil de sensibilidade in vitro de carrapatos de bovinos leiteiros a seis carrapaticidas comerciais em cinco propriedades do noroeste paulista, localizadas nos municípios de Bady Bassitt e Ipiguá, além de investigar as características produtivas e métodos de controle de carrapatos empregados nestas propriedades. Fêmeas ingurgitadas de R. (B.) microplus foram coletadas de bovinos naturalmente infestados e submetidas ao teste de imersão de adultas frente aos seguintes princípios ativos: amitraz, cipermetrina, deltametrina, associação clorpirifós/cipermetrina, associação diclorvós/cipermetrina e associação diclorvós/clorpirifós. Em cada propriedade, também foi aplicado um questionário. Considerando-se a eficácia média entre todas as propriedades, nenhum produto mostrou eficácia desejável. Os piretroides obtiveram os piores resultados (eficácias médias de 17% e 27%, respectivamente, para cipermetrina e deltametrina), sendo que em todas as propriedades havia resistência. Já amitraz (73%), clorpirifós/cipermetrina (79%) e clorpirifós/diclorvós (76%) mostraram as maiores eficácias médias. Em dois rebanhos os carrapatos foram resistentes a todas as formulações. Os produtores não conheciam o biocarrapaticidograma e aplicavam carrapaticidas sem critério técnico. Os resultados mostram a necessidade de orientação aos produtores quanto à utilização do biocarrapaticidograma como critério para escolha do acaricida. Um monitoramento constante da resistência também é relevante. Outros estudos na região devem ser feitos para melhor caracterização do nível de resistência.
Assuntos
Animais , Acaricidas/farmacologia , Carrapatos/classificação , Bovinos/classificação , Rhipicephalus/classificaçãoRESUMO
Rhipicephalus (Boophilus) microplus tick is one of the most important parasite afflicting cattle, mainly in taurine breed. Chemical application is still the most widely used way of control, although there are reports of tick resisting to many active principles in different countries. The goal of this study was to obtain the in vitro sensitivity profile of dairy cattle ticks to six commercial acaricides in five small farms in northwestern São Paulo state, located in Bady Bassitt and Ipiguá municipalities, and to investigate the productive characteristics and tick control methods applied in these farms. R. (B.) microplus engorged females were collected from naturally infested cattle and subjected to adult immersion test using the following drugs: amitraz, cypermethrin, deltamethrin, chlorpyrifos/cypermethrin mix, dichlorvos/cypermethrin mix, and dichlorvos/chlorpyrifos mix. In each farm, a questionnaire was also administered. Considering the mean efficacy level from all farms, there was no product with appropriate efficacy level. Pyrethroids had the worst results (cypermethrin and deltamethrin having mean efficacy of 17% and 27% respectively), with resistance observed in all farms. Conversely, amitraz (73%), chlorpyrifos/cypermethrin (79%), and chlorpyrifos/dichlorvos (76%) exhibited the highest mean efficacies. The ticks were resistant to all formulations in two herds. The cattle farmers were not aware of tests that detect ticks susceptibility to acaricides and did not adopt proper technical procedure when using chemicals. These indicate the need to educate cattle farmers on considering resistance as a product choice criterion. A constant monitoring of resistance is also relevant. Further investigations in the region should be conducted to better understand the resistance levels.
O carrapato Rhipicephalus (Boophilus) microplus é um dos parasitos mais importantes em bovinos, principalmente nos de raça taurina. O controle químico ainda é a forma mais utilizada para o seu controle, porém, há relatos de resistência dos carrapatos a vários princípios ativos em diversos países. O presente trabalho objetivou obter o perfil de sensibilidade in vitro de carrapatos de bovinos leiteiros a seis carrapaticidas comerciais em cinco propriedades do noroeste paulista, localizadas nos municípios de Bady Bassitt e Ipiguá, além de investigar as características produtivas e métodos de controle de carrapatos empregados nestas propriedades. Fêmeas ingurgitadas de R. (B.) microplus foram coletadas de bovinos naturalmente infestados e submetidas ao teste de imersão de adultas frente aos seguintes princípios ativos: amitraz, cipermetrina, deltametrina, associação clorpirifós/cipermetrina, associação diclorvós/cipermetrina e associação diclorvós/clorpirifós. Em cada propriedade, também foi aplicado um questionário. Considerando-se a eficácia média entre todas as propriedades, nenhum produto mostrou eficácia desejável. Os piretroides obtiveram os piores resultados (eficácias médias de 17% e 27%, respectivamente, para cipermetrina e deltametrina), sendo que em todas as propriedades havia resistência. Já amitraz (73%), clorpirifós/cipermetrina (79%) e clorpirifós/diclorvós (76%) mostraram as maiores eficácias médias. Em dois rebanhos os carrapatos foram resistentes a todas as formulações. Os produtores não conheciam o biocarrapaticidograma e aplicavam carrapaticidas sem critério técnico. Os resultados mostram a necessidade de orientação aos produtores quanto à utilização do biocarrapaticidograma como critério para escolha do acaricida. Um monitoramento constante da resistência também é relevante. Outros estudos na região devem ser feitos para melhor caracterização do nível de resistência.
RESUMO
A field survey of resistance was conducted based on the larval packet test technique with synthetic pyrethroids (cypermethrin and deltamethrin) and organophosphates (chlorpyriphos) in Rhipicephalus (Boophilus) microplus field populations from six different regions of the State of São Paulo (Brazil). 82.6% of the populations showed resistance to cypermethrin, 86.36% to deltamethrin and 65.25% to chlorpyriphos, with 50% presenting resistance to both SP and OP acaricide. According to the questionnaires completed by the producers, OP+SP mixtures followed by SP-only formulations were the products most commonly used for controlling the cattle tick in the surveyed areas. The present study showed high occurrence of resistance to SP and OP in the State of São Paulo, Brazil and revealed the type of strategy adopted by small dairy farms in this state. This information is fundamental in order to establish the monitoring of resistance on each farm individually, contributing to the rational use of acaricides for the control of R. (B.) microplus.
Assuntos
Doenças dos Bovinos/parasitologia , Inseticidas , Rhipicephalus/crescimento & desenvolvimento , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Clorpirifos , Feminino , Resistência a Inseticidas , Masculino , Nitrilas , Piretrinas , Inquéritos e Questionários , Infestações por Carrapato/prevenção & controleRESUMO
Fipronil is a phenylpyrazolic insecticide that is widely used in agriculture and has been recently used to control the cattle tick, Rhipicephalus (Boophilus) microplus. Because of the serious problems associated with resistance to the available acaricides, this product has been used as an important alternative to control acaricide-resistant ticks. The objective of this work was to analyse the fipronil sensitivity of ticks that were collected from farms with a history of fipronil use by larval bioassays. A total of 11 Brazilian tick populations were studied: one population from Rio Grande do Sul, one population from Mato Grosso do Sul and nine populations from São Paulo. To validate the assays, susceptible reference strains, POA (Porto Alegre, Brazil) and Mozo (Dilave, Uruguay), and ticks from six different farms that never used fipronil were tested. The resistance of various tick populations to technical grade fipronil (95.3%) was primarily evaluated using the larvae immersion test (LIT) and the larval packet test (LPT), when a sufficient number of larvae was collected. Using the LIT, the resistance ratios (RR(50)) of the tick populations from Rio Grande do Sul and Mato Grosso do Sul were 14.9 and 2.6, respectively, and the populations derived from São Paulo had RR(50)s ranging from 2.5 to 6.9. Four populations were evaluated with the LPT, and two populations displayed lower RR(50), while other populations displayed higher RR(50) than those determined by the LIT. This article reports the first cases of fipronil resistance in Brazil and highlights the LIT as a more sensitive technique for the evaluation of fipronil resistance in R. (B) microplus ticks. We suggest the use of the LIT as an evaluation tool for monitoring fipronil resistance in the control programmes of R. (B) microplus.
Assuntos
Doenças dos Bovinos/parasitologia , Inseticidas/farmacologia , Pirazóis/farmacologia , Rhipicephalus/crescimento & desenvolvimento , Infestações por Carrapato/veterinária , Animais , Bioensaio , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Resistência a Inseticidas , Larva/crescimento & desenvolvimento , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controleRESUMO
The aim of the present work was to compare the efficiency of methyl-formamide (MF), dimethyl-formamide (DF) and glycerol (GL) as cryoprotectants in canine semen cryopreservation. For the experiment, pooled semen was submitted to one of the three cryoprotectants, with a final concentration of 3% in egg yolk-TRIS extender. Semen was subjectively evaluated for total and progressive motility, vigour and morphology. Sperm membrane functional integrity was assessed by hypo-osmotic swelling test (HOST), and longevity was assessed using the thermoresistance test (TRT). Fresh semen showed normal physical and morphological characteristics. After thawing, differences were observed between semen frozen using GL and DF, regarding total and progressive motility and vigour (p < 0.05), but not between MF and GL or MF and DF. Means for total motility, progressive motility, vigour and morphologically normal spermatozoa were, respectively, 69.0 +/- 5.4%, 61.0 +/- 7.4%, 2.9 +/- 0.5 and 57.1 +/- 5.0% for GL; 59.0 +/- 8.9%, 50.0 +/- 10.0%, 2.5 +/- 0.7 and 66.9 +/- 7.7% for MF; and 44.0 +/- 21.0%, 37.0 +/- 19.8%, 2.1 +/- 0.6 and 61.1 +/- 5.5% for DF. On HOST, GL was superior (p < 0.05) to MF and DF (57.8 +/- 12.4%, 35.8 +/- 18.4% and 34.4 +/- 9.4%, respectively). During the TRT, both GL and MF were superior to DF, with no differences between GL and MF. In conclusion, the use of MF as cryoprotectant showed results similar to GL, and can be considered as an alternative in canine semen cryopreservation. Further studies testing different concentrations of MF may improve its effects on cryopreservation of canine semen.