Extensive rearing hinders Maedi-Visna Virus (MVV) infection in sheep
Fecha
2006Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
|
10.1051/vetres:2006034
Resumen
Maedi-Visna Virus (MVV) seroprevalence and its relationship with housing and mode
of rearing of replacement ewe-lambs was investigated in 38 non-randomly selected sheep-flocks in
Spain. They included extensive lamb-producing Manchega cross-bred flocks raised almost permanently
at pasture, semi-intensive Latxa dairy flocks housed 2–8 months/year and intensively raised
Assaf dairy flocks housed mos ...
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Maedi-Visna Virus (MVV) seroprevalence and its relationship with housing and mode
of rearing of replacement ewe-lambs was investigated in 38 non-randomly selected sheep-flocks in
Spain. They included extensive lamb-producing Manchega cross-bred flocks raised almost permanently
at pasture, semi-intensive Latxa dairy flocks housed 2–8 months/year and intensively raised
Assaf dairy flocks housed most time and at higher stocking density in less ventilated buildings than
other flocks. Most flocks raised replacement lambs naturally with their dams until weaning and as
a separate flock thereafter until lambing at one year of age. Seroprevalence (95% confidence intervals)
was 77%, 25% and 5% (4–6) in intensive, semi-intensive and extensive flocks, respectively
and the median (interquartile range) flock-seroprevalence was 82% (66–94) in intensive flocks, 31%
(14–31) in semi-intensive flocks and 4% (0–7) in extensive flocks. Seroprevalence was lowest in one
year-old sheep and increased to flock levels during the year after introduction into the adult flock in
most intensive flocks and more gradually in other flocks. Adult flock seroprevalence was associated
with housing time but this relationship was not evident within a particular rearing system, indicating
that other unknown factors are critical in horizontal MVV-transmission. Low seroprevalence in
extensive flocks further supports previous indications that lactogenic MVV-infection is relatively
inefficient and horizontal transmission is necessary to ensure long-term maintenance of MVV and
this could explain that MVV has not been reported from countries with mainly extensively reared
sheep such as Australia and New Zealand. Moreover, it indicates that MVV-control in extensive and
semi-intensive flocks can be simple and inexpensive. [--]
Materias
Maedi-Visna virus,
Sheep,
Seroprevalence,
Intensive and extensive rearing,
Spain
Editor
EDP Sciences
Publicado en
Veterinary Research, 37 (2006) 767–778
Departamento
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Versión del editor
Entidades Financiadoras
This work was financially supported by grants AGL2003-08977-c03-03 of the Ministerio de Ciencia y Tecnología and SED2003011 and SED2005008 of the Departamento de Agricultura of the Basque Government.