Intermediate Cluster Disinfection: Which Disinfection Solution Is Most Effective on Milking Liners? A Comparison of Microorganism Reduction on Liner Inner Surfaces Using Quantitative Swab Sampling Technique

Abstract

During machine milking, pathogenic microorganisms can be transmitted from cow to cow through liners. Therefore, in Germany, a spray method for the intermediate disinfection of the milking cluster is often used for prevention. This method of cluster disinfection is easy to perform, requires little time and no extra materials, and the disinfection solution is safe from outside contamination in the spray bottle. Since no data on a systematic efficacy trial are available, the aim of this study was to determine the microbial reduction effect of intermediate disinfection. Therefore, laboratory and field trials were conducted. In both trials, two sprays of 0.85 mL per burst of different disinfectant solutions were sprayed into the contaminated liners. For sampling, a quantitative swabbing method using a modified wet–dry swab (WDS) technique based on DIN 10113-1: 1997-07 was applied. Thus, the effectiveness of disinfectants based on Peracetic Acid, Hydrogen Peroxide and Plasma-Activated Buffered Solution (PABS) was compared. In the laboratory trial, the inner surfaces of liners were contaminated with pure cultures of Escherichia (E.) coli, Staphylococcus (S.) aureus, Streptococcus (Sc.) uberis and Sc. agalactiae. The disinfection of the contaminated liners with the disinfectants resulted in a significant reduction in bacteria with values averaging 1 log for E. coli, 0.7 log for S. aureus, 0.7 log for Sc. uberis and 0.8 log for Sc. agalactiae. The highest reduction was obtained for contamination with E. coli (1.3 log) and Sc. uberis (0.8 log) when PABS was applied and for contamination with S. aureus (1.1 log) and Sc. agalactiae (1 log) when Peracetic Acid Solution (PAS) was used. Treatment with sterile water only led to an average reduction of 0.4 log. In the field trial, after the milking of 575 cows, the liners were disinfected and the total microorganism count from the liner surface was performed. The reduction was measured against an untreated liner within the cluster. Although a reduction in microorganisms was achieved in the field trial, it was not significant. When using PAS, a log reduction of 0.3 was achieved; when using PABS, a log reduction of 0.2 was obtained. The difference between the two disinfection methods was also not significant. Treatment with sterile water only led to a reduction of 0.1 log. The results show that spray disinfection under these circumstances does result in a reduction in the bacteria on the milking liner surface, but for effective disinfection a higher reduction would be preferred.

Which Factors Influence the Consumption of Antibiotics in Q-Fever-Positive Dairy Farms in Northern Germany?

“…On the other hand, the parameter udder-cluster disinfection while milking had a strong increasing influence on the MTF. This management tool to reduce udder infections while milking has been studied for many years [29]. Recent studies show that the use of peracetic acid-based udder-cluster disinfection can lead to a reduction in teat-canal colonization [30].…”

Innovative Elastomers with Antimicrobial Activity May Decrease Infection Risks during Milking

“…However, this method is often seen as troublesome in many dairy herds and requires additional labor. Other methods, such as cluster disinfection, have produced controversial results [14][15][16]. The risk of transmission increases when automated milking systems are used because proper segregation is practically impossible to achieve, owing to the requirement of maintaining a consistent number of cows per unit, and since hygiene procedures are not always effective [31][32][33].…”

“…The use of backflush systems, which clean and disinfect milking units between cows, has been suggested as a way to reduce the risk of infection without segregation. Unfortunately, the results of this practice are mixed, and these systems alone do not reduce the incidence of intramammary infections [14][15][16]. These risks are even higher when automated milking systems are used, as a single milking unit can milk up to 60-70 cows, which increases the risk of infection and the incidence of chronic mastitis [17][18][19].…”

Effects of Milking System Operating Conditions on the Milk-Fat-Percentage Measuring Accuracy of an Inline Light-Scattering Sensor

“…To determine the number of bacterial colonies (TMC) and the number of Staphylococcus (aureus and epidermidis) from the total TMC by taking surface samples (samples were taken by swabbing), the stages of preparation, fixation and Gram staining of the smear were performed in accordance with the methodological recommendations for the organization of industrial microbiological control at dairy industry enterprises [21,22]. Microbiological control was carried out in a commercial laboratory.…”