Frequency of Neospora caninum infections in beef cow-calf operations under extensive management

Authors
Rodríguez, A. M.; Maresca, Sebastián; Cano, D. B.; Armendano, J. I.; Combessies, G.; Lopéz Valiente, S.; Odriozola, Ernesto Raul; Späth, E.J.L.; Odeón, Anselmo Carlos; Campero, Carlos Manuel; Moore, Dadin Prando
Publication Year
2016
Language
English
Format
article
Status
Published version
Description
The aim of this study was to evaluate the frequencies of Neospora caninum horizontal and vertical transmissions in beef cow-calf operations under three different extensive management systems: group A: 0.75 head per hectare pasturing on natural grass; group B: 1.1 head per hectare on natural grass and improved cultured pastures; and group C: 2 head per hectare on natural grass, improved cultured pasture and whole corn silage. Serum samples from 72 multiparous cows assigned to each beef cow-calf operations were obtained every 3 months during 2 years. A group of 30 replacement heifers from each group were tested similarly since they were 10-21 months old. Twenty four, 20 and 34 calves from groups A, B and C respectively, were bled before colostrum intake and again 6 months later. The samples were analyzed by indirect fluorescence antibody test (IFAT) for detection of total IgG against N. caninum at a serological titre ≥200 for multiparous cows and replacement heifers, and a serological titre ≥25 for calves. Serum samples from seropositive cows were assessed by ELISA to evaluate the avidity of their specific antibodies. There were no differences in the proportion of seropositive cows from groups A, B and C at the beginning of the trial (p > 0.05). Interestingly, the lowest serological titres in seropositive cows from all groups were observed during the first trimester (p < 0.05). Although seropositive cows had medium to high avidity antibodies, suggesting chronic infection; seroconversion associated with low antibody avidity was found in 2, 3 and 3 seropositive cows from groups A, B and C. All replacement heifers remained seronegative. No abortions were recorded but 2, 1, and 2 calves from groups A, B and C were seropositive before colostrum intake, respectively. Seropositive calves born from cows having intermediate or high avidity remained with the same serostatus at 6 months of age. Even under varying extensive management conditions, both N. caninum horizontal and vertical transmission methods do occur in beef cow-calf operations.
Fil: Rodríguez, A. M.. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Maresca, Sebastián. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Cano, D. B.. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Armendano, J. I.. Universidad Nacional de Mar del Plata; Argentina
Fil: Combessies, G.. Laboratorio Azul; Argentina
Fil: Lopéz Valiente, S.. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Odriozola, Ernesto Raul. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Späth, E.J.L.. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Subject
BEEF CATTLE
NEOSPORA CANINUM
SEROLOGY
STOCKING RATE
TRANSMISSION
Otras Ciencias Veterinarias
Ciencias Veterinarias
CIENCIAS AGRÍCOLAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/62265