[Antiparasitic effects of peracetic acid (PAA) against infective stages (theronts) of white spot disease, Ichthyophthirius multifiliis in vitro]. / Antiparasitäre Effekte von Peressigsäure (PES) gegen infektiöse Stadien (Theronten) der Weisspünktchenkrankheit, Ichthyophthirius multifiliis in vitro.

White spot disease, caused by the protozoan parasite Ichthyophthirius multifiliis (I. multifiliis), invades nearly all fresh water fish species and causes huge economic losses. In Germany no protocide substance is legal for the treatment of I. multifilis. As an alternative substance the peracetic acid (PAA) was tested to treat the free invasive stage (theront) of the parasite. PAA concentrations of 0.3 ppm were able to kill all theronts in 120 min in our investigations. As a result of these investigations we recommend an interval-application of 0.3 to 0.5 ppm PAA for 30 to 150 min. This application should be prolonged for two life cycles of the parasite. Biotic parameters as e. g. fish species, and age as well as abiotic parameters as e. g. temperature, pH and organic load of the water could possibly influence the efficiency of the PAA application and should therefore be taken into account while picking the dosage and length of the PAA exposure.

[Application of peracetic acid for the treatment of juvenile sander (Sander lucioperca) during Ichthyophthirius multifiliis infestation]. / Einsatz von Peressigsäure zur Behandlung juveniler Zander (Sander lucioperca) bei Ichthyophthirius-multifiliis-Befall.

White spot disease caused by the ciliate protozoan parasite Ichthyophthirius multifiliis (I. m.), is one of the most dangerous diseases in aquaculture and ornamental fish breeding worldwide. The parasite is characterized by three developmental stages: a reproductive tomont, an infective theront and a parasitic trophont. In sander (Sander lucioperca) breeding I. m. causes serious economic losses. After banning of the traditional therapeutic agent malachite green we have to face a state of emergency for the treatment of the ichthyophthiriasis in Germany. The peracetic acid (PAA), characterized by positive therapeutical properties, might close this gap. The purpose of our investigations was the determination of the toxicity of PES to juvenile sander as well as the evaluation of the therapeutic effectiveness of the substance to combat I. m. For juvenile sander (length 3 cm) we determined a 24-h-LC50 of 1.14 (0.97; 1.3) ppm PES. In two investigations PAA was applied in daily intervals of 0.5; 1, 3, 5 and 24 h and concentrations of 0.5; 1; 1.5 and 2 ppm to treat I.-m.-infection in sander. In test I all sander (length 9 cm) died as a result of the I.-m.-infection. However, the PAA exposed fish survived longer than the PES-free controls! This might be due to a disinfection of other pathogens by PAA. In test II, the fish (length 12 cm) were less infected than fish in test I. Four of six fish died in the group exposed with 2 ppm PAA for 24 hours. The abundance of I.-m.-trophonts was determined in mucus, fin and gill tissues of all fish. Significant differences could not be observed between test I and test II because of dissimilar: 1. exposure in time and concentration, 2. age and condition of the fish and 3. homogenity of the variances. Therefore, no therapy strategy was successful while fighting the parasitic trophonts protected by the overlaying fish tissues. We speculate that a successful therapy of I. m. with PAA is, as known e.g. for malachite green, only possible while fighting the free living stages theronts and tomonts. This will be part of our subsequent investigations.

[Tenacity of Salmonellae in environmental media and their distribution with waste products]. / Die Tenazität der Salmonellen in Umweltmedien und ihre Verbreitung mit Abprodukten.

Feedstuffs and foodstuffs of animal origin have to make allowance for measures of animal hygiene as well as measures which serve for protection of human health. A fundamental task of animal hygiene is to recognize and avert the infectious risk which follow from feedstuffs contaminated by residual products as well as Salmonella contaminated feedstuffs well-timed. The behaviour of reproduction and survival of Salmonella in environmental media and on plants is determined by endogenous factors of the microorganisms themselves and by environmental conditions on the media. It is entered into the achieved level of knowledge of survival behaviour of Salmonella in environmental media and the treatment processes and storage technologies for residual products which usually are estimated in agriculture. In opinion of the authors, new technological procedures are essential for an effective hygienic treatment of residual products for the successfully prevention of animal epidemics and their fighting.

[Estrus synchronization in cattle by means of chlormadinone acetate ("Bovisynchron" Jenapharm) in the tropics. II. First results of the estrus synchronization of cattle with "Bovisynchron" at the Republic of Mali]. / Synchronisation des chaleurs de bovins par acétate de chlormadinon ("Bovisynchron" jenapharm) sous les tropiques Deuxiéme partie: les premiers résultats de la synchronisation de chaleur chez les bovins avec "Bovisynchron" en République du Mali

The first experiments are reported on oestrus synchronization in cattle in the Republic of Mali. The animals recieved Bovisynchron twice a day orally over a period of 15 days. The synchronization effect was marked; insemination was performed on the 5th and 6th day p.s. The intensity of the oestrus and especially the results of pregnancy are in close relationship to the breeding conditions and the general status of the animals. The oestrus synchronization is considered a favourable biotechnical method for regulating the reproduction provided that the animals are kept stationary or temporarily stationary.

[Estrus synchronization in cattle using chlormadinone acetate ("Bovisynchron" Jenapharm) in the tropics. 1. On the effect of blocking the cycle using chlormadinone acetate and on the introduction of this biotechnical method in the Republic of Mali]. / Synchronisation des chaleurs de bovins par acétate de chlormadinon ("bovisynchron" jenapharm) sous les tropiques. Le mécanisme de blocage du cycle sexuel par l'acetate de chlormadinon et l'introduction de cette méthode biotechnique en republique du mali

The oestrus synchronization in cattle is being tested as a biotechnical method supporting the implementation of the crossing programme in the Republic of Mali Using the latest results of sexual physiology, the effect is described of Bovisynchron Jenapharm (chlormadinonacetate). Bovisynchron is characterised by a high certainty of synchronization and a good toleration. It leads to a highly fertile oestrus of all animals and to a high rate of conception. An analysis of the situation in the Republic of Mali is used to discuss the advantages of this method.