Management-Associated Risk Factors for Heifer Mastitis before and after Parturition in German Dairy Herds.

Subclinical mastitis in heifers during early lactation affects udder health, future milk production and, therefore, the risk of premature culling. The aim of this cross-sectional study was to identify pre- and post-partum risk factors associated with a high heifer mastitis rate (HMR), and to find out which period (either pre- or post-partum) contains more risk factors and consequently should be the focus of mastitis control in heifers. A total of 77 herds were included in this study and the potential animal- and farm-related risk factors were recorded during a one-time farm visit. The HMR was provided by the dairy herd improvement test (DHI) as the annual average of the past 11 DHIs. For this study, data were analyzed in two models using generalized linear models. Each model examined the association between possible risk factors and HMR, one including only prepartum risk factors and the other one only post-partum risk factors. One identified pre-partum risk factor was the proportion of udder-healthy cows in the herd. Post-partum risk factors were the type of teat cleaning procedure before milking, teat disinfection, treatment of mastitis in heifers, a body condition score (BCS) of >3.0 in fresh heifers, and the combination of a teat cleaning procedure with a teat disinfectant. The results show the importance of the period shortly after calving for udder health in heifers, as four of the five significant risk factors were identified in this period and three of them were related to the milking process. However, further research with a higher number of herds is needed to minimize individual herd effects.

Efficacy of a commercial glutaraldehyde footbath product for the control of bovine digital dermatitis.

OBJECTIVE: To evaluate the relative efficacy of a novel, commercially available disinfecting agent containing ≥ 15 to < 20 % glutaraldehyde in a hydro-colloid matrix ("EIMÜ Klauen Sprint®"; Eimermacher, Nordwalde, Germany, Biozid-Desinfektionsmittel, BAuA Nr. N-57213) as a walkthrough footbath in order to treat digital dermatitis of dairy cattle. MATERIAL AND METHODS: The study was conducted in a dairy farm located in northern Germany from June 1st, 2015 to September 5th, 2015. Eighty-eight cows were enrolled in this study. In both trials of the study, a walkthrough footbath was applied on five consecutive milking times per week. Trial 1 was a blinded, randomised and controlled intervention study. The therapy group (n = 40) received the novel glutaraldehyde product in a 2 % solution while the control group (n = 40) was led through a footbath containing pure water. Trial 2 was a longitudinal study to investigate the development of claw health over a longer time period regarding the use of the new footbath solution. In trial 2 the disinfecting footbath was applied to all trial cows (therapy and control group) of trial 1. The development of claw health and lameness was systematically monitored in the two groups on days 0, 9, 17, 29, 35 (trial 1) and days 42, 68, 94 (trial 2), respectively. The adjusted odds of digital dermatitis lesions (DDL) throughout the study were analysed by mixed logistic regression models. RESULTS: The odds of DDL were 0.15 for the glutaraldehyde foot-bath group compared to the control group. Hence, the disinfecting footbath significantly reduced the DDL prevalence and increased the cure rate of DDL. However, no preventive effect on new digital dermatitis (DD) cases could be identified. CONCLUSION: The efficacy of the novel glutaraldehyde footbath was evaluated and it was concluded that "EIMÜ Klauen Sprint®" was well tolerated over a longer period of time and might therefore be an effective tool to control DD. CLINICAL RELEVANCE: In future, "EIMÜ Klauen Sprint®" could be used within a Mortellaro sanitation concept and thereby might help to solve a major problem of dairy cattle farms.

[Physiological processes in the mammary gland tissue of dairy cows during the dry period]. / Die physiologischen Vorgänge im Eutergewebe der Milchkuh während der Trockenstehperiode.

The dry period is essential for the bovine mammary gland to regenerate after the previous lactation. This period is necessary to render an appropriate milk yield during the subsequent lactation. Furthermore, the dry period allows the cure of existing infections of the mammary gland, but also bears an increased risk of new infection. The physiological processes within the bovine mammary gland can be devided in the following way: During the first days of active involution, a change in the cellular architecture is suggested, possibly caused by the high intra-alveolar pressure. Extensive histological changes affecting the capability of synthesis and secretion of milk components are also observed. During the involution, there is a loss of integrity of the mammary epithelial and various substances enter from blood into the mammary lumen. The histological and morphological changes continue during the steady state involution and the period of neolactogenesis. Hence, the composition of the secretion produced by the mammary epithelia changes markedly. Furthermore, the phases of the dry period differ in regard to the susceptibility towards intramammary infections. Therefore, it is necessary to consider the physiological processes during dry cow management. This literature survey describes the essential findings about the changes within the mammary tissue during the dry period.