Ivermectina e abamectina em diferentes doses e vias de aplicação contra larvas de Cochliomyia hominivorax em bolsas escrotais de bovinos recém-castrados, provenientes da região sudeste do Brasil

The preventive efficacy of ivermectin and abamectin administered in different routes (subcutaneous, intramuscular and pour-on) and doses (200 and 500mcg kg(-1)) against Cochliomyia hominivorax in the scrotal sac of cattle after castration, was evaluated. Animals from six different farms, in the state of Sao Paulo and Minas Gerais, Brazil were used. For each study, 3045 uncastrated bulls, depending on the number of groups, were selected. On day zero of the study, the procedure was carried out by the method of bloody castration and the animals were treated after this process. The efficacy of ivermectin and abamectin administered via the pour-on (500mcg kg(-1)), subcutaneous (200mcg kg(-1)) as well as the efficacy of abamectin intramuscularly (200mcg kg(-1)) were evaluated. In each experiment, one group of animals was kept as control. The animals were evaluated from the 3rd to the 14th day after castration process/treatment. The efficacy values for both active principles were <= 30% the next day 10 post-treatment (PT), and in five experiments, both ivermectin and abamectin, regardless of the route of administration, were ineffective (0.0%) on the day 10th PT. Based on the results found in this study, conducted in different properties from southeastern Brazil, both ivermectin and abamectin, when used the protocol presented, were considered ineffective in preventing scrotal myiasis in bulls, irrespective of the route of administration and dose used.

Resistência de Haemonchus placei, Cooperia punctata e Oesophagostomum radiatum à ivermectina pour-on a 500mcgkg-1 em rebanhos bovinos no Brasil

The broad spectrum of endectocides and the easy use mode of their pour-on formulations are factors that have stimulated a higher frequency of use these drugs in cattle. In this study was evaluated the efficacy of ivermectin pour-on using the dose of 500mcgkg(-1), against nematodes in naturally infected cattle from different herds. Twelve calves were brought from each of the four farms selected. All the 48 calves used showed mean of eggs per gram of feces (EPG) greater than 500 considering three consecutive counts. Subsequently, animals from each herd were divided into two groups of six animals each, one treated pour-on with ivermectin 500mcgkg(-1) and other kept as untreated control. Calves were euthanized 14 days after treatment for counting the endoparasites. Ivermectin showed null effect against H. placei in all the herds evaluated. The drug was also ineffective against C. punctata in the herds from Jaboticabal, SP and Formiga, MG, and reached efficacy of 75.8% and 58.4% in herds from Sao Jose do Rio Pardo, SP and Sao Sebastiao do Para so, MG, respectively. Efficacies of 94.2% (Jaboticabal), 0.0% (Sao Jose do Rio Pardo), 94.2% (Formiga) and 39.2% (Sao Sebastiao do Para so) were detectedagainstO. radiatum. Based on these results obtained on the present study, the four populations of Haemonchus placei and Cooperia punctata evaluated were resistant to ivermectin pour-on using a dose of 500mcgkg(-1). Ivermectin-resistant strains of Oesophagostomum radiatum were found in two of the four herds evaluated.

Efeito de diferentes frequências de manejos no temperamento de bovinos de corte

Pós-graduação em Zootecnia - FCAV

Milho ou polpa cítrica associados à glicerina na alimentação de bovinos de corte confinados

Pós-graduação em Zootecnia - FCAV

Glicerina associada à ureia na alimentação de bovinos Nelore

Pós-graduação em Zootecnia - FCAV

Desenvolvimento, validação e confiabilidade de uma escala de dor aguda pós-operatória em bovinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da microinfiltração marginal em restaurações de classe V em resina composta em dentes bovinos: efeito de diferentes equipamentos para preparos cavitários e sistemas adesivos

Pós-graduação em Odontologia Restauradora - ICT

Precocidade sexual em bovinos Nelore avaliada por ultrassonografia testicular

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A utilização de glicerina em dietas para bovinos altera a microbiota ruminal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)