PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Tancredi M.G.F., Faccini J.L.H., Tancredi I.P., Martins I.V.F. & Scott F.B. 2005. [The host-relationship between Psoroptes equi and horses.] Relação parasito-hospedeiro entre Psoroptes equi e eqüinos. Pesquisa Veterinária Brasileira 25(4):207-209. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br Horses, abandoned by their owners (stray horses) along the main roads in the state of Rio de Janeiro, southeastern Brazil, and brought by the Federal Police to a quarantine station at the Universidade Federal Rural do Rio de Janeiro, were included in the study. A total of 1,121 horses were examined from November 1998 to November 2000. Skin scrapings from 107 (9.5%) horses with signs of psoroptic mange resulted in 37 (34.6%) positive animals for Psoroptes equi. There was no statistical correlation between prevalence and host age or sex (c2, p>0,05). P. equi was diagnosed in animals with different hair color. The dorsal region (withers to hip) was the most affected area of the body.

• Psoroptes equi Acari Psoroptidae mange horses Brazil.

Abstract in Portuguese:

Tancredi M.G.F., Faccini J.L.H., Tancredi I.P., Martins I.V.F. & Scott F.B. 2005. [The host-relationship between Psoroptes equi and horses.] Relação parasito-hospedeiro entre Psoroptes equi e eqüinos. Pesquisa Veterinária Brasileira 25(4):207-209. Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: faccini@ufrrj.br Horses, abandoned by their owners (stray horses) along the main roads in the state of Rio de Janeiro, southeastern Brazil, and brought by the Federal Police to a quarantine station at the Universidade Federal Rural do Rio de Janeiro, were included in the study. A total of 1,121 horses were examined from November 1998 to November 2000. Skin scrapings from 107 (9.5%) horses with signs of psoroptic mange resulted in 37 (34.6%) positive animals for Psoroptes equi. There was no statistical correlation between prevalence and host age or sex (c2, p>0,05). P. equi was diagnosed in animals with different hair color. The dorsal region (withers to hip) was the most affected area of the body.

Abstract in English:

Soto P., Echevarría H.M., Monteavaro C.E. & Catena M.C. 2005. Experimentally induced intravaginal Tritrichomonas foetus infection in a mouse model. Pesquisa Veterinária Brasileira 25(4):225-230. Laboratory of Clinical and Experimental Microbiology, Facultad de Ciencias Veterinarias, UNCPBA, Pinto 399, Tandil (7000), Buenos Aires, Argentina. E-mail: psoto@vet.unicen.ar The interest to develop research on the host-parasite relationship in bovine tritrichomonosis has accomplished the use of experimental models alternative to cattle. The BALB/c mouse became the most appropriate species susceptible to vaginal Tritrichomonas foetus infection requiring previous estrogenization. For the need of an experimental model without persistent estrogenization and with normal estrous cycles, the establishment and persistence of vaginal infection on BALB/c mouse with different concentrations of T. foetus in two experimental groups was evaluated. Group A was treated with 5mg of b-estradiol 3-benzoate to synchronize the estrous, 48 hours before the T. foetus vaginal inoculation, and Group B was inoculated in natural estrus. At 5-7 days after treatment, estrogenic effect decreased allowing all animals to cycle regularly during the experiment. From the first week post-infection, samples of vaginal mucus were taken from all animals during 34 weeks, in order to evaluate the course of infection and the stage of the estrus cycle. Group A showed 93.6% of infected animals, and Group B showed 38%. Different doses of T. foetus were assayed to establish the vaginal infection, with a persistence of 34 weeks. Although different behavior was observed in each subgroup belonging to either Group A or Group B, there were no significant differences among the infecting doses used. The b-estradiol 3-benzoate treatment had a favorable effect on the establishment of the infection (P<0.0001), but it did not influence its persistence (P=0.1097). According to the results, an experimental mouse model is presented, appropriate for further studies on mechanisms of pathogenicity, immune response, protective evaluation of immunogen and therapeutic effect of drugs.

• Tritrichomonas foetus mouse model experimental tritrichomonosis.

Abstract in Portuguese:

Soto P., Echevarría H.M., Monteavaro C.E. & Catena M.C. 2005. Experimentally induced intravaginal Tritrichomonas foetus infection in a mouse model. Pesquisa Veterinária Brasileira 25(4):225-230. Laboratory of Clinical and Experimental Microbiology, Facultad de Ciencias Veterinarias, UNCPBA, Pinto 399, Tandil (7000), Buenos Aires, Argentina. E-mail: psoto@vet.unicen.ar The interest to develop research on the host-parasite relationship in bovine tritrichomonosis has accomplished the use of experimental models alternative to cattle. The BALB/c mouse became the most appropriate species susceptible to vaginal Tritrichomonas foetus infection requiring previous estrogenization. For the need of an experimental model without persistent estrogenization and with normal estrous cycles, the establishment and persistence of vaginal infection on BALB/c mouse with different concentrations of T. foetus in two experimental groups was evaluated. Group A was treated with 5mg of b-estradiol 3-benzoate to synchronize the estrous, 48 hours before the T. foetus vaginal inoculation, and Group B was inoculated in natural estrus. At 5-7 days after treatment, estrogenic effect decreased allowing all animals to cycle regularly during the experiment. From the first week post-infection, samples of vaginal mucus were taken from all animals during 34 weeks, in order to evaluate the course of infection and the stage of the estrus cycle. Group A showed 93.6% of infected animals, and Group B showed 38%. Different doses of T. foetus were assayed to establish the vaginal infection, with a persistence of 34 weeks. Although different behavior was observed in each subgroup belonging to either Group A or Group B, there were no significant differences among the infecting doses used. The b-estradiol 3-benzoate treatment had a favorable effect on the establishment of the infection (P<0.0001), but it did not influence its persistence (P=0.1097). According to the results, an experimental mouse model is presented, appropriate for further studies on mechanisms of pathogenicity, immune response, protective evaluation of immunogen and therapeutic effect of drugs.

Abstract in English:

Catto J.B., Bianchin I., Torres Junior R.A.A. 2005. [Effects of deworming of cow-calf beef herds in brazilian savannas.] Efeitos da everminação de matrizes e de bezerros lactentes em sistema de produção de bovinos de corte na região de Cerrado. Pesquisa Veterinária Brasileira 25(3):188-194. Embrapa Gado de Corte, Rodov. 162, Km 4, Campo Grande, MS 79002-950, Brazil. E-mail: catto@cnpgc.embrapa.br The effect of deworming with ivermectin of cows before calving and of suckling calves on fecal egg counts (EPG) and productive performance of two beef cattle herds in Central Brazil was studied. Four groups of pregnant cows received the following treatments: T1- cows and calves not treated, T2- only calves treated, T3- only cows treated, and T4- cows and calves treated. The calves of T2 and T4 were distributed in the following treatments: A- calves treated at 3 to 5 months of age with long action ivermectin, B- treated with ivermectin, and C- control. For the cows, the deworming did not diminish the EPG during lactation and also did not have significant effect on the conception rate, live weight gain and the body weight of their calves at 3 to 5 months of age. The calves of treatment A gained, from the time of treatment to weaning (84 to 108 days), an average of 4.2kg (P=0.0003) and 7.1kg (P<0.0001) more than those of treatment B and C, respectively. The average difference in live weight gain of 2.9kg between the animals of treatment B and C was not significant. The EPG before treatment was not significantly different from the treatments (P=0.8665); but at weaning, the average EPG of the calves from treatment A was lower than for treatment B (P=0.0004) and C (P<0.0001). There was no significant difference in the mean EPG for the calves from treatment B and C.

• Beef cattle cows suckling calves nematodes treatment Brazilian savannas.

Abstract in Portuguese:

Catto J.B., Bianchin I., Torres Junior R.A.A. 2005. [Effects of deworming of cow-calf beef herds in brazilian savannas.] Efeitos da everminação de matrizes e de bezerros lactentes em sistema de produção de bovinos de corte na região de Cerrado. Pesquisa Veterinária Brasileira 25(3):188-194. Embrapa Gado de Corte, Rodov. 162, Km 4, Campo Grande, MS 79002-950, Brazil. E-mail: catto@cnpgc.embrapa.br The effect of deworming with ivermectin of cows before calving and of suckling calves on fecal egg counts (EPG) and productive performance of two beef cattle herds in Central Brazil was studied. Four groups of pregnant cows received the following treatments: T1- cows and calves not treated, T2- only calves treated, T3- only cows treated, and T4- cows and calves treated. The calves of T2 and T4 were distributed in the following treatments: A- calves treated at 3 to 5 months of age with long action ivermectin, B- treated with ivermectin, and C- control. For the cows, the deworming did not diminish the EPG during lactation and also did not have significant effect on the conception rate, live weight gain and the body weight of their calves at 3 to 5 months of age. The calves of treatment A gained, from the time of treatment to weaning (84 to 108 days), an average of 4.2kg (P=0.0003) and 7.1kg (P<0.0001) more than those of treatment B and C, respectively. The average difference in live weight gain of 2.9kg between the animals of treatment B and C was not significant. The EPG before treatment was not significantly different from the treatments (P=0.8665); but at weaning, the average EPG of the calves from treatment A was lower than for treatment B (P=0.0004) and C (P<0.0001). There was no significant difference in the mean EPG for the calves from treatment B and C.

Abstract in English:

Grazing behaviour, ponderal growth and level of parasitic infestation were studied in Suffolk breed sheep, from 1994 to 1995, in Nova Odessa, São Paulo. Two management systems were compared: restricted grazing, where the animals were released to the pastures at 9:50am and confined at 5:30pm, and 24 hour grazing, where the animals were maintained all the time in the paddocks, but with access to shelters. Thirty-four adult ewes were used in the summer period (17 under restricted grazing and 17 full-time grazing), and 42 ewes in the winter period (21 with restricted grazing and 21 full-time grazing). Also, for both seasons, 12 traceranimals, six in each grazing system, were used to obtain worm counts from their digestive tracts. For three consecutive days, grazing behaviour, that is, whether grazing or not, was observed in January/February (summer) and July/August (winter) at 30 minute intervals from 7:00am to 5:30pm, also whether the animals stayed in the sun or shade, irrespective of whether they were grazing or not. The level of parasitic infestation was evaluated under each system by eggs per gram countings (EPG) of the herd and the traceranimals, as well as by larvae count. It was concluded that restriction of grazing time by itself does not provide any effective control of parasitic infestation in sheep, however a better control was obtained in the summer period. Restricted grazing time was compensated by the greater activity of the animals during the hotter hours of the day, however, this behaviour affected the animal performance, resulting in lower weight gains. Greater forage availability in relation to estimated consumption may explain the similarity between the grazing times observed in both management systems, either in the summer or in the winter.

• Sheep Suffolk grazing behaviour management parasitic infestation

Abstract in Portuguese:

Foi estudado o comportamento em pastejo, o desempenho ponderal e o nível de infestação parasitária em ovelhas da raça Suffolk, no período de 1994 a 1995, em Nova Odessa, SP. Comparou-se dois sistemas de manejo: pastejo restrito, onde os animais foram soltos às 9:50h e presos às 17:30h e pastejo em período integral, no qual os animais não eram recolhidos, tendo a disposição abrigo para passarem a noite. Foram utilizadas 34 fêmeas adultas no verão (17 em pastejo livre e 17 em pastejo restrito) e 42 fêmeas adultas no inverno (21 em pastejo livre e 21 em pastejo restrito). Trabalhou-se ainda com 12 animais traçadores em cada estação do ano, sendo metade em cada sistema de manejo visando a contagem de nematódeos no trato digestivo dos animais. Durante 3 dias consecutivos nos meses de janeiro/fevereiro (verão) e julho/agosto (inverno) estudou-se, através da observação dos animais, a cada 30 minutos entre as 7:00 e 17:30h, o hábito de pastejo (pastando ou não; na sombra ou no sol). Acompanhou-se o nível de infestação parasitária dos animais em cada sistema, pela contagem do OPG do rebanho e dos traçadores e nematódeos recuperados nos traçadores. Concluiu-se que a restrição do horário de pastejo isoladamente não propiciou um controle efetivo da infestação parasitária nos animais mostrando. A restrição do tempo de pastejo é compensada pela maior atividade dos animais nas horas mais quentes do dia, todavia este comportamento afetou o desempenho, resultando em menor ganho de peso. A maior disponibilidade de forragem, em relação ao consumo estimado, pode explicar a similaridade entre os tempos de pastejo verificados nos dois sistemas de manejo, tanto no verão como no inverno.

• Ovinos Suffolk hábito de pastejo sistema de manejo infestação parasitária