The use of antibiotics in animal husbandry must be reduced - this is a clearly expressed wish of many consumers. Excessive use for prevention and treatment can lead to antibiotic resistance, also with consequences for the human sector. This calls for a rethink and a much more conscious use of antibiotics in livestock farming in general. New management methods are also required to support the reduced use of antibiotics. But what options are there for reducing the use of antibiotics in dairy farming? The Mecklenburg-Vorpommern State Research Centre for Agriculture and Fisheries (LFA) invited participants to an online seminar on this topic on 17 March 2021 as part of the Focus on Animal Welfare network. 39 interested parties from all over Germany joined in to find out about practical solutions.

Professor Volker Krömker (MSO Cattle Health, University of Copenhagen) explained when it makes sense to use antibiotics for mastitis and when no improvement in udder health can be achieved. He sees the main task of dairy farmers as being to take preventative measures to minimise the risk of mastitis, such as consistently enforcing strict hygiene management with corresponding documentation. This can prevent the development and spread of mastitis and avoids the problem of going from "catastrophe to catastrophe". The use of rapid diagnostic tests to identify pathogens is another valuable tool to determine the advisability of using antimicrobials in treatment. Animals with incurable diseases should not be treated with antibiotics. These include animals with a persistently high cell count, a high incidence of mastitis or those in whose milk samples no germs or gram-negative bacteria are detectable.

But how can the use of antibiotics be reduced by changing management measures, such as selective drying off? Samira Dietze (Bavarian State Research Centre for Agriculture (LfL)) provided information on the "RAST" project (reduction of antibiotic use through selective drying off). The "RAST" decision tree shows which herd requirements must be met in order to be able to dispense with the conventional use of antibiotic dryers during drying off. The herd total milk cell count should not exceed 200,000 cells/ml in the last three milk yield tests and the new infection rate in the dry period should be less than 25 %. If the individual animal also has a cell count below 200,000 cells/ml in the last three milk performance tests, no clinical mastitis and is negative in both the bacteriological examination and the ultrasound test, the use of antibacterial dryers can be dispensed with in this animal. Farmers for whom this is too unsafe can choose stricter limits for themselves. It is important to try out this procedure once and to keep a close eye on how udder health develops in animals without bacterial dryers by means of close monitoring of success, such as a scarf test after calving.

Extending the calving interval is also one of the frequently discussed methods for reducing the use of antibiotics. Dr Anke Römer (State Research Institute for Agriculture and Fisheries (LFA), Mecklenburg-Vorpommern) and Klaus-Dieter Augustin (Rinderzucht Augustin KG) showed why this procedure can be promising. Due to the enormous increase in performance in the German Holstein breed in recent years, animals with sometimes 25 to 30 kg milk (daily yield) are being dried off. It is easy to see that this can be problematic. Animals with good persistence in the lactation curve should therefore be given more time between calving and first insemination. Extending the inter-calving period results in a reduction in the critical phases (birth and first month of lactation) and a lower milk yield for drying off. At the same time, the number of dry periods in the total utilisation period per cow is automatically reduced, which also reduces the measures required to prevent mastitis during drying off. With optimal feed management, it can therefore be assumed that the use of antibiotics is minimised, both on the farm as a whole per herd and cow as well as across the entire dairy farm. Mr Augustin presented considerable data from his farm, where this procedure has been successfully implemented for a long time. He has not had to accept any increased losses due to infertility or obesity.

Author: Patricia Lößner, State Research Centre for Agriculture and Fisheries Mecklenburg-Western Pomerania