Assessment of weight gain and control of parasitism by Rhipicephalus microplus in dairy cattle in the field using organosynthetic parasiticide, phytotherapics and homeopathy / Avaliação do ganho de peso e controle do parasitismo por Rhipicephalus microplus em bovinos leiteiros a campo usando parasiticida organosintético, fitoterápicos e homeopatia

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)

Association of BoLA-DRB3.2 alleles with tick (Boophilus microplus) resistance in cattle

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%)...

Açäo larvicida de derivados arilsulfonílicos da (+)- cânfora e da (+)- isopinocanfona sobre o carrapato Boophilus microplus / Larvicidal action of (+)-camphor and (+)- isopinocamphone arilsulphonyl derivatives on Boophilus microplus cattle tick

Testou-se a atividade larvicida de 33 derivados arilsulfonílicos da (+)-cânfora e da (+)-isopinocanfona no carrapato B. microplus, na busca de princípios ativos menos tóxicos para o seu controle. Os produtos foram obtidos por clorossulfonaçäo da (+)-cânfora e da (+)-isopinocanfona. Eles foram submetidos à solubilizaçäo e testados separadamente e em conjunto contra larvas de carrapato encerradas em envelopes contendo papéis impregnados e acondicionadas em estufa climatizada. A mortalidade média näo atingiu 5 por cento em todos os testes realizados, indicando que a clorossulfonaçäo näo é a rota de síntese mais adequada para a obtençäo de derivados sintéticos com efeito larvicida sobre B. microplus. Os 33 produtos testados sob a forma de triagem biológica näo podem ser considerados como potenciais acaricidas