ABSTRACT
The goal of this research was to compare the effect of the following products on dairy cattle, parasitized by Rhipicephalus microplus: organosynthetics - Clorfenvinfós and Ivermectina (OG); phytotherapics - Eucalyptus oil (EG) and Neem cake (NG); Homeopathy (HG); The control group (CG) received no treatment. Infestation was by R. microplus (MIC) and weight gain (GP) were evaluated. The study included 60 animals (5 groups) from Dutch / Zebu, aged between 25-44 months and initial weight between 211-477kg. EG and NG showed MIC 84.9% and 14.0% greater than CG, respectively (P <0.05; P = 0). HG and OG had MIC less than CG 24.4% and 16.9%, respectively (P<0.05; P <0.05). EG, NG and OG obtained GP lower than CG in 7.9%, 8.9% and 8.06% (P <0.05) respectively. The HG GP was 4.9% higher (P <0.05) than CG. This was the first research to prove parasitism control by R. microplus in a field test, using homeopathy. The methodology for choosing Homeopathy for the control of enzooties, developed and tested for the first time in this study, proved to be adequate and efficient, opening the possibility for establishing a new methodology for strategic control of parasitism by R. microplus.(AU)
O objetivo desta pesquisa foi comparar o efeito dos seguintes produtos sobre bovinos leiteiros, parasitados por Rhipicephalus microplus: organossintéticos - clorfenvinfós e ivermectina (OG); fitoterápicos - óleo de eucalipto (EG) e torta de Neem (NG) e homeopatia (HG). O grupo controle (CG) não recebeu tratamento. Foram avaliados infestação por R. microplus (MIC) e ganho de peso/grupo (GP) em 60 animais (5 grupos), a partir de holandês/zebu, com idade entre 25 e 44 meses e peso inicial entre 211 e 477kg. EG e NG apresentaram MIC 84,9% e 14,0% maior que CG, respectivamente (P<0,05; P=0). HG e OG apresentaram MIC menor que CG 24,4% e 16,9%, respectivamente (P<0,05; P<0,05). EG, NG e OG obtiveram GP menor que CG em 7,9%, 8,9% e 8,06% (P<0,05), respectivamente. O GP do HG foi 4,9% maior (P<0,05) que o CG. Esta foi a primeira pesquisa a comprovar controle do parasitismo por R. microplus em teste a campo, usando homeopatia. A metodologia para escolha de medicamentos homeopáticos para controle de enzootias, desenvolvida e testada pela primeira vez neste estudo, mostrou-se adequada e eficiente, abrindo a possibilidade para estabelecimento de nova metodologia para controle estratégico do parasitismo por R. microplus.(AU)
Subject(s)
Animals , Female , Cattle , Ticks , Homeopathic Remedy , Tick Control/methods , AcaricidesABSTRACT
This work evaluated the in vitro effects of Steinernema glaseri on the biology of engorged Amblyomma cajennense nymphs. The ticks were exposed to infective juveniles (IJs) of S. glaseri at different concentrations. Each treatment was composed by 10 experimental units (EU = repetitions) in Petri dishes maintained at 27 ± 1º C and relative humidity (RH) > 80 ± 10% for 72 hours. Then the nymphs were transferred to Petri dishes free of nematodes for observation of the following parameters: pre-ecdysis period (PEP), ecdysis period (EP), molting period (MP), ecdysis percentage (%Ec) and mortality percentage (%Mt). The groups treated with 5,000 and 10,000 IJs/EU showed significant alterations in the PEP when compared to the control, while for the EP only the treatment with 10,000 IJs/EU produced any significant changes compared to the control. The MP did not differ significantly from the control in any of the treated groups. For the %Ec only the group treated with 10,000 IJs/EU differed significantly from the control. The greatest efficiency was obtained at the concentration of 10,000 IJs/EU, in which the mortality percentage was 13%. This demonstrates that the nematode utilized was not able to cause high mortality in engorged A. cajennense nymphs and agrees with other reports indicating that immature ticks are not highly susceptible to entomopathogenic nematodes.
Esse trabalho avaliou os efeitos in vitro de Steinernema glaseri sobre a biologia de ninfas ingurgitadas de Amblyomma cajennense. Os carrapatos foram expostos a juvenis infectantes (JI) de S. glaseri sob diferentes concentrações. Cada tratamento foi composto de 10 unidades experimentais (EU = repetições) em placas de Petri mantidas sob 27 ± 1º C e UR > 80 ± 10% por 72 horas. Em seguida, as ninfas foram transferidas para placas de Petri isentas de nematoides para observação dos seguintes parâmetros: período de pré-ecdise (PPE), período de ecdise (PE), período de muda (PM), porcentagem de ecdise (%Ec) e porcentagem de mortalidade (%Mt). Os grupos tratados com 5.000 e 10.000 JI/UE mostraram alterações significativas no PPE quando comparados com o controle, enquanto para o PE somente o tratamento com 10.000 JI/UE produziu mudanças significativas quando comparado com o controle. Não houve diferença significativa do PM em relação ao grupo controle em nenhum dos tratamentos e, para a %Ec, somente o grupo tratado com 10.000 JI/UE diferiu significativamente do controle. A maior eficiência foi obtida com a concentração de 10.000 JI/EU na qual a mortalidade foi de 13%. Isso demonstra que o nematoide utilizado não foi capaz de causar alta mortalidade em ninfas ingurgitadas de A. cajennese e concorda com outros relatos indicando que carrapatos imaturos não são altamente susceptíveis a nematoides entomopatogênicos.
Subject(s)
Ticks , Nematoda , Tick ControlABSTRACT
Losses caused by bovine tick burdens in tropical countries have a tremendous economic impact on production systems. Besides reducing production, this parasite can cause death in the most susceptible animals. The use of commercial acaricides has been the major method of control, but their misuse has led to tick resistance to many chemicals. More recently, vaccines have been used in some countries without solving the problem completely. An alternative could be the development of resistant animals and the use of genetic markers and candidate genes that could help with the enormous task of selecting resistant animals. The bovine lymphocyte antigen genes (BoLA) have been shown to be associated with some parasitic infestations and disease incidence. Thus, the objective of the present study was to determine the association of BoLA-DRB3.2 alleles with tick resistance in cattle. The study was conducted on 231 F2 (Gyr x Holstein) animals that were artificially infested with 10,000 tick larvae. Log of tick count +1 was used as the dependent variable in a mixed animal model with allele substitution effects in addition to fixed effects of year and season at tick count, sex of calves, age of animal at tick count, hair type (short-straight, short-curl, long-straight, and long-curl), coat color (white, >75% white, 50- 75% white, and 25-50% white), and additive genetic, permanent environmental and residual effects as random. Females showed fewer ticks than males. Animals with short-straight hair were more resistant to tick infestation than animals with long-curl hair, and animals with whiter coat color also had fewer ticks. An association between BoLA alleles and lower tick number was found for alleles DRB3.2 *18, *20 and *27 at the 5% significance level. Also, one allele (DRB3.2*16) showed an association at the 10% level. Allele *27 was the most frequent in the population (30.7%), followed by alleles *16 (10.8%), *20 (8.7%) and *18 (2.4%)...
Subject(s)
Animals , Male , Female , Alleles , Cattle Diseases/genetics , Cattle/genetics , Histocompatibility Antigens Class II/genetics , Tick Infestations/veterinary , Cattle Diseases/immunology , Cattle Diseases/parasitology , Cattle/immunology , Cattle/parasitology , Genetic Markers , Genetic Predisposition to Disease , Genotype , Models, Genetic , Polymerase Chain Reaction , Quantitative Trait, Heritable , Seasons , Tick Infestations/genetics , Tick Infestations/immunologyABSTRACT
Larvas provenientes de duas fêmeas de Amblyomma dissimile Koch, 1844 (Acari: Ixodidae), naturalmente ingurgitadas em uma iguana (Iguana iguana) e provenientes do Estado do Mato Grosso, foram utilizadas na infestação experimental de lagartos da espécie Tropidurus torquatus e coelhos domésticos. As larvas alimentadas em ambos os hospedeiros realizaram ecdise para ninfas. As ninfas apenas ingurgitaram no lagarto e mudaram para machos e fêmeas. Este é o primeiro registro do parasitismo de larvas e ninfas de A. dissimile em T. torquatus e de larvas em coelhos.
Subject(s)
Animals , Rabbits , Tick Infestations , Lizards , Larva , NymphABSTRACT
Ixodes amarali was reported for the second time in the State of Rio de Janeiro, southeastern Brazil, from an engorged female obtained from a naturally infested opossum (Didelphis sp.). Biological characteristics of de non-parasitic phase were studied, under controlled conditions (temperature of 27ñ1§C, relative humidity higther than 80 per cent and scotophase)