Martinez Herrera D.I.,University of Veracruz |
Morales Morales J.A.,University of Veracruz |
Peniche Cardena A.E.,University of Veracruz |
Molina Sanchez B.,University of Veracruz |
And 5 more authors.
International Journal of Dairy Science | Year: 2010
With the aim to evaluate strain RE51 Brucella abortus vaccine under field conditions in goats and ovine communities, located at Perote and Coffer Region in Veracruz, Mexico, where, prevalence rates varies, several vaccination operatives were done between 12 to 15 months, using 3×108 to 3×109 Colony Forming Units (CFU) of such vaccine for each animal. A total of 5,168 goats or ovine females 3 months old and older, were vaccinated. Those animals belonged to 322 herds in different communities. Vaccination was done despite their reproductive condition. Twenty animals were randomly selected in each herd and blood samples collected, before and after 12 to 15 months of vaccination, in order to determine brucellosis seroprevalence. Sample size for each community was estimated by a probabilistic model, with unknown population and 50% known prevalence rate (n = 1-p/pv); where, n corresponds to sample size, p for prevalence rate and v variation coefficient (0.05), blood samples were taken by jugular vein punction using vacuum tubes system. The sera collected were tested by using 3% antigen concentration card test as screening and complement fixation as confirmation test, according with Mexican regulations. During the first sampling tests it was found that seroprevalence rates in the communities were: 0, 0.5, 4.5, 5, 38 and 1.4%. The rates of seroprevalence in the second sampling were: 0, 0, 5.5, 0 and 0%. The rates of serum reactors were reduced 80% from different rates to 0.0%. According with these results, RE51 Brucella abortus strain vaccination provided a successful response at the indicated dosage. It is conclusive that RE51 Brucella abortus strain goat and ovine vaccination at communities from Perote and Coffer Region is useful for brucellosis control. © 2010 Academic Journals Inc.
Barradas-Pina F.T.,CE La Posta INFAP |
Martinez-Herrera D.I.,University of Veracruz |
Peniche-Cardena A.E.J.,University of Veracruz |
Serna-Montero R.D.,University of Veracruz |
And 4 more authors.
Journal of Animal and Veterinary Advances | Year: 2012
With the aim of measuring preescapular lymph node response in bovines vaccinated with either SI 9 or RB51 Brucella abortus strains vaccines, two herds were selected. About 40 females were divided in two groups of 20; group 1 was vaccinated and group 2 left as unvaccinated control. Vaccinated group, 3 and 6 months females were vaccinated with 5×10 10Colony Forming Units (CFU) dosage and >6 with a 3×l0 8-3×l0 8SI 9 strain. For the second herd same age females and dosage was used but applying RB51 strain. Vaccines were subcutaneously applied at mid third on left side of the neck. Preescapular lymph nodes were measured in length and wide at 90 and 180 days after vaccination. Results were analyzed by Chi-square. At 90 days post vaccine, lymph nodes dimensions were 3.7-4.8 cm wide×10-11.7 cm length and for unvaccinated 3.8-4.5×10-11.5 cm. No statistical differences were found (p>0.05) among vaccinated and unvaccinated controls. After 180 days post vaccine similar results were found with RB51 for both groups but strain 19 vaccinated herd was different (p<0.05) however, differences were found in control group. Results indicate that both strains are efficiently processed by lymphatic tissue among 90 days after vaccination and therefore, they may be considered as safe without producing macroscopic changes that alter organ dimensions. © Medwell Journals, 2012.
Peniche-Cardena A.,University of Veracruz |
Martinez-Herrera D.,University of Veracruz |
Franco-Zamora J.L.,University of Veracruz |
Canudas-Lara E.,University of Veracruz |
And 6 more authors.
Journal of Animal and Veterinary Advances | Year: 2012
Annual economic losses by bovine brucellosis in Latin America are estimated at 600 million American dollars (USD). In Mexico, the economic impact has not been quantified since reliable information about disease prevalence in cattle is scarce. In endemic areas the use of RB51 strain is a common practice, nevertheless the information about their efficiency is also scarce. The objective of the present study was to evaluate by clinical trial the efficiency of this vaccine in dual purpose herds naturally infected with brucellosis under tropical conditions. Vaccinated and non-vaccinated groups were integrated with 88 females each one. Reactor animals were not eliminated or separated from cattle population. A herd with an initial seroprevalence rate of 5% was selected and monitored during eighteen months post-vaccination. The vaccination efficiency shows that there were no losses with the control program and without the control program there were losses in the amount of 38,680 USD ($406,140 Mexican currency [Mex. cy]) estimating the loss per animal at 325 USD ($3,419.56 Mex. cy). The preventive program cost was 6,112 USD ($64,184 Mex. cy). The cost for maintaining non-productive reactor animals in the herd was estimated at 31,137 USD ($326,940.00 Mex. cy). The most affected parameters were fertility and milk production indicators. Benefit/cost ratio was 4.7:1 for milk production, 6.2:1 for calf sales and 6.6:1 for the combination of milk production and calf sales. It was concluded that the use of RB51 vaccine in the control program gives assurance of economic profitability. © Medwell Journals, 2012.