[Field report from large-scale killing of ducks]. / Erfahrungsbericht aus der Massentötung von Enten.

An outbreak of avian influenza in August 2007 resulted in the culling of hundreds of thousands of Peking ducks. An earlier tutorial had shown that whole house gassing with carbon dioxide to kill waterfowl has to be refused because of interference with animal welfare. Culling by electrocution is a reliable method that fulfils animal welfare requirements. Stationary electrocution lines for slaughtering should be preferred if suitable for the killing of the birds. Mobile electrocution lines (MET) are a good alternative or supplementation with a capacity of circa 2,500 animals per hour. MET are suitable for killing Peking ducks with a weight of approximately 500 g. At least two veterinarians are required per MET for the supervision of animal welfare during culling. When following German animal welfare laws, killing in mobile gas containers filled with carbon dioxide is an alternative with a capacity comparable to that of MET. The problem of looking into the containers for controlled stunning and killing can be solved by installing observation windows. Manpower requirements are comparable to those of MET, while requirements for material and transportation are unlikely higher. This method is suitable for birds which are too small to be killed by electrocution.

Differentiation of Mycobacterium paratuberculosis isolates by rDNA-spacer analysis and random amplified polymorphic DNA patterns.

The ability to distinguish between isolates of Mycobacterium paratuberculosis isolates was studied using two molecular techniques. Nucleotide sequence analysis of the rDNA-spacer and random amplified polymorphic DNA (RAPD) analysis using decamer primers with GC contents of 60 to 70% were evaluated on 16 isolates of M. paratuberculosis from cattle. The rDNA spacer analysis did not discriminate between isolates as it revealed an identical sequence for all 16 strains tested but it showed one common difference to the sequence previously described for M. paratuberculosis J2A. In the RAPD analysis, 14 of the 60 decamer primers used resulted in distinct amplification products for most of the isolates. For seven of the primers the size of the amplification products varied among strains thus allowing the specific identification of eight of the 16 isolates; of the remaining eight isolates five could each be differentiated from 14 other isolates, two from 13, and one from 12 isolates. Therefore, these data illustrate the possibility of using RAPD-analysis with certain primers for the differentiation of individual M. paratuberculosis isolates.

[Legal report: expert opinion. Can the induction of abortion in heifers mated accidentally and too young be expected from the owner?]. / Fallbericht: Gerichtsgutachten. Kann einem Tierbesitzer die Aborteinleitung bei durch ungewollten Deckakt zu früh belegten Rindern zugemutet werden?

The objective of the presented expert opinion is the reasonability of a termination of unwanted pregnancies for the owner of young heifers mated accidentally by a bull. Because the heifers were too young when conceiving they showed retarded growth and dystocia when delivering after normal course of pregnancy. These problems could have been avoided by pregnancy diagnosis and subsequent induction of abortion in time.

[Effect of progesterone on the immune system in consideration of bovine placental retention]. / Einfluss von Progesteron auf das Immunsystem mit Berücksichtigung der bovinen Retentio secundinarum.

Effects of progesterone on the immune system of different species are presented by a literature study. Elevated progesterone concentrations in blood result in more severe course and longer persistence of bacteria in infectious diseases and decrease of the clearance of antibody-coated erythrocytes in vivo. Progesterone suppresses specific components of the immune system and natural killer (NK) cell activity while it has a mainly positive influence on other nonspecific components. It suppresses blastogenesis and cytotoxicity of lymphocytes and increases synthesis of asymmetric antibodies without effector function to block fetal antigens. Progesterone increases the concentration of leucocytes in blood, random migration and chemotactic ability, synthesis of reactive oxygen intermediates (ROI) and antibody-dependent cellular cytotoxicity of polymorphonuclear leucocytes (PMN) and expression of complement receptors, synthesis of ROI and phagocytosis of peritoneal macrophages. In the uterus mainly immunosuppressive effects of progesterone are described (decreased migration of PMN into the gravid uterus, persistence of bacteria or transplants, synthesis of immunosuppressive uterine milk proteins, decreased random migration of PMN) except for an increased content of IgA in the secretory products indicating a significance of progesterone in the pathogenesis of endometritis mainly in the cow and bitch. No correlation could be found between blood concentrations of progesterone and placental retention in cattle. Progesterone takes part in avoiding immunologic aggression of the maternal organism against the semiallogenic conceptus by suppressing specific components of the immune system and NK cell activity. Positive effects on nonspecific components of the immune system could be regarded as compensatory mechanisms to maintain the efficiency of the complete immune system.

[Effect of estrogens on the immune system with regard to bovine placental retention]. / Einfluss von Ostrogenen auf das Immunsystem mit Berücksichtigung der bovinen Retentio secundinarum.

A survey of effects of estrogens on the immune system is given by a literature study. Changes in number and functionality of single populations of cells of the immune system are shown. Results often vary in dependence on the examined parameters, on the type of the used or measured estrogens, on the measuring methods and between the different species. Independent from that the capacity of the nonspecific cellular immune system seems to be increased under the influence of estrogens. Individuals with high estrogen levels showed an increase of the number of leucocytes and neutrophil granulocytes in the blood. In most of the functional studies on neutrophil granulocytes a suppressive effect of estrogens independent from the species could only be observed on the ability of directed migration. A stimulation or no effects of estrogens were reported on all the other parameters (random migration, phagocytosis, generation of reactive oxygen metabolites, cytotoxicity). Less is known about the effects of estrogens on mononuclear cells (lymphocytes, monocytes, natural killer cells). Mainly lymphocytes showed a decrease in their number in the blood and a suppressive effect of isolated cells in different species. It remains for further studies whether estrogens are of significance for bovine retained placenta by having effects on components of the immune system, and how significant they are.

[Differentiation of yeasts in mastitis milk] . / Differenzierung von Hefen in Mastitismilch.

Differentiating 174 yeasts from clinical samples to get a survey of those species found in mastitis milk and milking machines we identified five genera with 29 species. Species of the genus Candida dominated with 77% of all samples. More than 25% of yeasts from milk were identified as C. rugosa and more than 20% as C. catenulata. The six species found most often represented 74% of all yeasts in this group. Yeasts from milking machines were more heterogeneous.