01784nas a2200205   4500000000100000000000100001008004100002260007000043653001500113653001000128100001500138700001200153700001100165245014500176250001000321300001200331490000800343520121300351022001401564       2017                            d  c11/2017bSchlütersche Verlagsgesellschaft mbH & Co. KGaHannover10aMaed-Visna10asheep1 aK Hüttner1 aH Heyne1 aD Heim00aImpact of flock segregation according to the Maedi-Visna status on reproduction and lamb rearing – a field study in Mecklenburg-Vorpommern  a11/12  a490-4930 v1303 aThe chronic infection with the Maedi-Visna virus, a small ruminant lentivirus (SRLV) poses a substantial risk for herd health in sheep. A representative SRLV screening in Mecklenburg-Vorpommern in 2004 revealed an average serological prevalence of 51.2% of herds and an average prevalence of 28,8 % within infected herds. Based on these results the effect of the infection on selected herd parameters was investigated through segregation of Maedi-Visna positive and negative individuals at a study farm involving a total of 24 ewes. The results of our field study illustrate the serious impact of SRLV infection on the age of ewes in general and number of pregnancies in particular, on lamb rearing as well as lamb weight development post partum. Against the backdrop of a high SRLV prevalence level in the country‘s sheep flocks, farmers are called upon to adhere to the state guidelines for the voluntary Maedi-Visna scheme. In this context it is necessary to emphasize the need to revise animal health legislation with regards to MaediVisna in sheep as well as Caprine Arthritis Encephalitis in goats, which is currently at the expense of sheep farms already participating in SRLV screening programs.  a0005-9366