Bovine immunisation with a recombinant peptide derived from synthetic SBm7462® (Bm86 epitope construct) immunogen for Rhipicephalus microplus control.

RHIPICEPHALUS MICROPLUS: is the most important ectoparasite of livestock in tropical and subtropical areas around the world. Research focused on developing an efficient vaccine for cattle tick control is a high priority. The aim of this study was to evaluate the rSBm7462® peptide (Bm86-B and T cell epitopes) regarding its properties of immunogenicity, protective effect in cattle and efficacy against R. microplus. This peptide was produced by a fermentative process in the yeast culture system of Komagataella (Pichia) pastoris strain Km 71. The vaccination assay was conducted in a tick-free area using non-splenectomised Holstein Friesian calves, separated into immunisation and control groups. These animals individually received the recombinant peptide and the inoculum without peptide using saponin as an adjuvant at three time points. The calves were challenged 21 days after the last immunisation using 4500 larvae per animal. An indirect ELISA was used to identify the IgG kinetics of serum samples from the calves studied. The qPCR was performed to determine the cytokine gene expression from the total RNA of the cultured PBMCs. Histomorphometry of the germinal centres (GCs) was performed measuring slides with haematoxylin-eosin staining of surgically removed lymph nodes from immunised calves. The antibody response showed a significant induction of high-affinity IgGs in calves immunised with the recombinant peptide in comparison to the controls. The kinetics of antibodies in immunised calves showed a significant increase during the experiment. This increase in high-affinity IgGs correlated with a gradual increase of the GC diameter following each peptide vaccination. Cytokine expression profiles demonstrating an adaptive immune response in calves immunised with rSBm7462® confirmed the T-dependent response. Vaccine efficacy was calculated at 72.4 % following the analysis and fecundity of collected adult female ticks, compared between control and vaccinated groups. These findings demonstrate that this new recombinant peptide is an option for control of R. microplus infestations.

Frecuencia de anticuerpos anti-Neospora caninum en ovinos del departamento de Córdoba, Colombia / Frequency of antibodies anti-Neospora caninum in sheeps from the department of Cordoba, Colombia

Objetivo. Evaluar la frecuencia de anticuerpos anti-N. caninum en dos rebaños de ovinos del departamento de Córdoba-Colombia. Materiales y métodos. El estudio fue realizado en el departamento de Córdoba (Colombia) en dos explotaciones de ovinos que presentaron antecedentes de abortos y muerte de animales adultos. Se muestrearon 28 hembras adultas de pelo criollo (Camura), escogidas por muestreo aleatorio simple. Un péptido recombinante de Neospora caninum (NcGRA1) fue utilizado para el diagnóstico por DOT-ELISA y el suero fue diluido en 1:200. Resultados. Este estudio reporta por primera vez para el departamento y para el país la presencia de anticuerpos anti-N. caninum en el 78.6% (22/28) de los ovinos muestreados. Conclusiones. Estos resultados confirman la infección por Neospora caninum en ovinos y la necesidad de nuevos estudios que asocien la presencia del parasito con manifestaciones clínicas en diferentes regiones del país.

Objective. To investigate the effects of supplements with protected fat such as calcium soaps containing omega 3 or 6 milk production, composition and reproductive performance. Materials and methods. Twenty-four Holstein cows were used in a mixed model design. From 20 days before calving until 105 days postpartum, cows were assigned to different treatments; C: control diet, O6: animals supplemented with protected unsaturated fat including a higher amount of omega, 6 and O3: animals fed with protected unsaturated fat including higher amounts of omega 3. Milk volume and composition, and body condition score (CC) were determined, along with the first postpartum heat and ovulation. Results. Supplementation with omega 3 or 6 had no effect on milk volume, and fat percentages, protein, milk non-fat solids (SNF) and total solids (ST). However, there is a positive effect of omega 6 supplementation on the CC at 45 days postpartum (p<0.05). This was also reflected in a faster ovarian recovery (42.24±16.75 days to first postpartum ovulation). Conclusions. The use of omega 6 supplementation improves body condition score of animals during early postpartum, decreasing the days to the first ovulation and postpartum heat without affecting the volume or composition of the milk. Supplementation with omega 3 does not affect any productive parameters in the early postpartum.