ALENCE OF RUMINANT PESTIVIRUS INFECTIONS IN NAMIBIA
DEPNER, K., HUBSCHLE, O . J. B. & L1ESS, B. , 1991. Prevalence of ruminant pestivirus infections in Namibia. Onderslepoorl Journal ofVelerinary Research 58. 107-109 (1991) Following several clinical cases of suspected bovine virus diarrhoea .(BVD) on three Namibian ca ttle farms, a serological survey was cooducted on bovloe , ovme , capnne and wold rUffilOant sera originating from different regions of the country. Neutralizing antibodies to BVD ViruS (BVDV) were detected in 58 % of 1 014 cattle sera, 14 % of 618 sheep sera and 4,6 % of 1 118 goat sera. Sera from seven of teo wildlife species lVere positive with kudu , eland and giraffe having prevalence rates greater than 40 %. BVDV was isolated [rom six clinically affected bovlOes and three healthy heifers persistently infected with BVDV . The survey demonstrated that pestivirus infections are widespread 10 Namibia In hoth domestic and wild ruminants.
A direct neutralizing peroxidase-linked antibody assay for detection and titration of antibodies to bovine viral diarrhoea virus.
Summary 
 
A neutralization peroxidase-linked antibody (NPLA) assay in which the peroxidase-linked antibody is a BVDV specific gammaglobulin (direct NPLA assay) is described. 
 
 
 
Multiplication of BVDV isolate 0712/80 in MDBK cells, cultivated in nutrient medium with different serum supplements (5% V/V), yielded varying degrees of inhibitory effect on the replication of the virus. Infectivity titres of the virus were considerably higher in medium supplemented with horse serum than with ox or two different batches of commercial foetal calf sera. 
 
 
 
The relationship between virus dose (TCID50) and neutralizing dose (ND50) was assayed by direct NPLA. Using the 0712/80 isolate of BVDV, a neutralization slope of 2.54 was obtained for sequential sera of a calf inoculated intranasally with the same virus isolate. Consequently, an increase or decrease of 1 log10 unit in the TCID50 would result in an inverse change of approximately 0.4 log10 in the ND50. 
 
 
 
A comparison was made between the NPLA assay and the microtitre neutralization test (MNT) for the detection of BVDV neutralizing antibodies in field cattle sera. Out of 425 field cattle sera tested, 48% were positive by the NPLA assay while 45% were positive by the MNT. 
 
 
 
In pigs inoculated intranasally with different strains of BVDV (NADL or A 1138/69), antibodies against these strains were detectable much earlier by the NPLA assay than by the MNT. The antibody titres were also remarkably higher in NPLA assays than in MNT with the difference being more prominent in sera of pigs inoculated with the NADL strain than with strain A1138/69 of BVDV. 
 
 
 
Zusammenfassung 
 
Es wird ein Neutralisationstest ‘NPLA’ (Neutralization peroxidase-linked antibody) beschrieben, bei dem der Peroxidase-gekoppelte Antikorper ein BVD-virusspezifisches Gammaglobulin darstellt (direkter NPLA-Test). 
 
 
 
Bei der Vermehrung des BVD-Virusisolates 0712/80 in MDBK-Zellen, die in mit unterschiedlichen Seren (5% v/v) supplementierten Nahrmedien kultiviert worden waren, zeigten sich inhibitorische Effekte unterschiedlichen Ausmases auf die Virusreplikation. Die Infektiositatstiter des Virus waren deutlich hoher bei Medium, welches mit Pferdeserum supplementiert worden war, als bei Verwendung von Medium, dem Rinderserum oder zwei verschiedene Chargen von kommerziellem fotalen Kalberserum zugesetzt worden war. 
 
 
 
Es wurde der Zusammenhang zwischen der Virusdosis (KID50) und der Neutralisationsdosis (ND50) im direkten NPLA ermittelt. Unter Verwendung des BVD-Virusisolates 0712/80 konnte bei sequenziell gewonnenen Serumproben von einem intranasal mit demselben Virusisolat infizierten Kalb fur die Neutralisation ein Regressionskoeffizient von 2,54 ermittelt werden. Daraus folgte, das ein Anstieg oder Abfall der KID50 um eine log10-Stufe eine entsprechende umgekehrte Anderung der ND50 um 0,4 log10 bewirkte. 
 
 
 
Fur das Auffinden von neutralisierenden Antikorpern gegen BVD-Virus in Feldseren von Rindern wurde vergleichsweise der NPLA und der Mikrotiter-Neutralisationstest (MNT) eingesetzt. Mit Hilfe des NPLA wurden unter 425 Serumproben 48% als positiv, durch den MNT nur 45% positive Reagenten ermittelt. 
 
 
 
Bei intranasal mit verschiedenen BVD-Virusstammen (NADL und A1138/69) infizierten Schweinen konnten Antikorper gegen diese Stamme durch den NPLA fruher ermittelt werden als mit dem MNT. Auch die Antikorpertiter waren mit dem NPLA-Test wesentlich hoher als im MNT, wobei die Unterschiede deutlicher waren bei Serumproben von Schweinen, die mit dem BVD-Virusstamm NADL infiziert worden waren als bei solchen, die den Stamm A1138/69 erhalten hatten.
Keeping Farmers on the Land: Adding Value in Agriculture in the Veneto Region of Italy
Italy's relatively small area, high population density, and high land and labor costs have created the challenges of ensuring profitably for agricultural producers, slowing urban encroachment onto arable land, and keeping farm families on land that has been handed down within the families for generations. As part of the solution to these issues, the European Union is enacting policies to reduce producer dependence on direct subsidies while increasing the competitiveness of agricultural products and returns to producers, reinvigorating rural communities, and encouraging environmentally sound production methods. These regulations provide incentives for producers to add value to their products by obtaining legal recognition of typical products, participating in agritourism, and helping to promote traditional products for regional food systems. This paper examines how E.U. and national policies are encouraging farmers in the Veneto region of Italy to adopt an agricultural production model that encourages limited production of high-quality, high-value products and more diversified land use.