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Passive immunity transfer in Holstein cows immunized or not against rotavirus: serum immune response of calves

Grant number: 12/18814-1
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): November 01, 2012
Effective date (End): October 31, 2013
Field of knowledge:Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
Principal researcher:José Jurandir Fagliari
Grantee:Camila Bortoletto
Home Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Bovine rotaviruses (BRV) are the main etiologic agents of calf enteritis, comprising one of the most important causes of economic losses in cattle-raising all over the world. Since the main strategy of protection against diarrhea caused by BRV consists in the vaccination of the pregnant cow and the intake of a colostrum containing high levels of specific anti-rotavirus immunoglobulins by the calves along the first week of life, the knowledge of the effectiveness of passive immunity transfer and the influence of vaccination on immunoglobulin concentrations is ultimately important. In the face of controversial information verified in the literature, the aim of the present study is to evaluate the humoral immune response of cows immunized against rotavirus with inactivated commercial vaccine by immunonzymatic assay (EIE), and for this purpose, two groups will be formed: Group V1: 10 cows immunized with inactivated commercial vaccine against BRV and Group V2: 10 cows non-immunized against BRV. The female calves will also be allotted into groups according to the mother's distribution, for the evaluation of humoral immunity in serum after colostrum intake and the kinetics of acute phase proteins response along the first 30 days of life. The data will be evaluated by variance analysis and the contrast between mean values will be evaluated using the Tukey's test, considering the results significantly different when P<0,05.