The aim of this work was to gain insight into the frequency as well as the distribution of hemotrophic mycoplasmas in Germany. For this purpose, samples from 104 probands of a dairy cow herd from the farm of the Versuchs- und Bildungszentrum Landwirtschaft (VBZL) of the Chamber of Agriculture of North Rhine-Westphalia, Haus Riswick, were evaluated between May 2017 and February 2018. The work was an investigation approved by the North Rhine-Westphalian State Office for Nature, Environment and Consumer Protection in accordance with Section 8 (1) of the Animal Protection Act in the current version with the file number 84-02.04.2017.A096. The focus was on milk yield, markers of energy metabolism, red blood cell count and markers of acute phase reaction. As an additional parameter of the conducted study, half of the herd was treated with a pre-filled syringe Imrestor® (company Elanco Deutschland GmbH, Bad Homburg, Germany). Hence, the herd was divided into an experimental and a control group. Imrestor® (Elanco Deutschland GmbH, Bad Homburg, Germany) is a pre-filled syringe containing the active ingredient pegbovigastrim, which is a pegylated bovine granulocyte colony stimulating factor. This was approved to reduce the risk of clinical mastitis in dairy cows and heifers in the peripartum period up to 30 days after calving. The experimental group consisted of 62 subjects injected with Imrestor® 7 days prior to the expected calving date and within 24 h after calving. Since the experimental group was expected to have a modulated immune response of the cows, a statistical evaluation was performed at baseline to determine the extent to which the distribution of animals infected with hemotrophic mycoplasma and animals tested negative within the experi-mental group and control group were similar and to what extent Imrestor® had an effect on the distribution. In conclusion, the study showed a high prevalence (61 %, 64/104) of Mycoplas-ma wenyonii. In contrast, only slightly more than one third (39 %, 41/104) of the herd tested positive for Candidatus Mycoplasma haemobos and slightly less than one third (30 %, 31/104) for the presence of coinfection. Overall, approximately 71 % (74/104) of the cattle was tested positive. However, no distinction was made whether the cattle were infected with Candidatus Mycoplasma haemobos, Mycoplasma wenyonii, or both mycoplasma strains simultaneously. When examining the animals that had received Imrestor® and those that were in the control group, there was no difference between the prevalence at any time. Therefore, the conclusion was that Imrestor® had no effect on the detection of hemotrophic mycoplasmas. This parameter was therefore neglected in the further investigations and results. Moreover, the other parameters such as beta-hydroxybutyric acid, erythrocytes, reticulocytes, haptoglobin, and total protein did not show clinically relevant differences between infected or coinfected and non-infected or non-coinfected animals. Only the milk yield of animals infected with Candidatus Mycoplasma haemobos, Mycoplasma wenyonii and coinfected was on average 4,0 liters (10 %) lower than the milk yield of those tested negative. Infected and coinfected animals showed milk yields averaging 26,0 to 28,0 liters and non-infected and non-coinfected cattle milk yields were averaging 29,0 to 32,0 liters. Thus, our own work shows that although the infection rate is high in this herd, it has no clinically relevant effects on the red blood count or on markers of energy metabolism and markers of acute phase response. However, our own work also shows that Candidatus Mycoplasma haemobos infection, Mycoplasma wenyonii infection and coinfection may be associated with diminished milk yield.weiterlesen