Abstract
The reduction of antibiotic use in food producing animals becomes increasingly important. Therefore, suitable alternatives for mastitis treatment in dairy cows have to be considered. Oxytocin (OT) induces milk ejection and hence supports milk removal from infected mammary quarters. Beyond udder emptying, the injection of very high dosages of OT causes increased somatic cell counts (SCC) in milk and enables the transfer of immunoglobulins (Ig) from blood into milk through a reduced blood-milk barrier integrity. The aim of the present study was to investigate pathogen-specific changes of SCC, the blood derived milk components lactate dehydrogenase (LDH), serum albumin (SA), and IgG in milk of cows suffering from mastitis caused by different pathogens treated with two intravenous injections of high dosages of OT (100 IU). Milk samples from 184 dairy cows from different farms were collected on day1 (day of clinical examination and mastitis diagnosis) and on days2, 3, 14, and 28. Bacteriological examination (day1) identified involved pathogens. Cows were randomly assigned to treatment (OT injections on days1 and 2) or control group (no OT). Independently of the assigned experimental group, cows received the common therapy protocol of the veterinary practice after sample collection if the general condition was affected. Milk SCC, LDH, SA, and IgG changed specifically depending on involved pathogens. Highest values of all three parameters were measured in mastitis caused by Streptococcus uberis. Changes were less pronounced with other Streptococci spp., Staphylococci spp. or Corynebacterium bovis. Oxytocin treatment did not affect any of the studied parameters independent of the involved pathogen. Only in quarters infected with Staphylococci other than Staphylococcus aureus a decreased SCC and increased IgG concentrations in quarters, where no pathogens were detected, were observed. Thus, high dosage OT administration is obviously not suitable as a stand-alone mastitis treatment in dairy cows.
Highlights
In dairy cows, different pathogens can cause subclinical and clinical mastitis, which usually results in changes of milk composition.[1]
Pathogens were detected in 161 quarters, including 74 quarters of cows treated with oxytocin
The mean somatic cell counts (SCC) within pathogen groups before treatment was similar in treatment and control groups except in Streptococcus uberis infection in which the group that was not treated with OT started already with a significantly higher SCC
Summary
Different pathogens can cause subclinical and clinical mastitis, which usually results in changes of milk composition.[1] To achieve high standards of milk quality in dairy farming, mastitis is commonly treated with antibiotics. As the use of antimicrobial treatment in food producing animals is progressively losing acceptance due to the possible development of resistant pathogens as well as the possible occurrence of drug residues, alternative treatment strategies have to be considered and investigated. The use of high amounts of injected oxytocin (OT) has been discussed as a potential alternative to antimicrobial treatment. At a physiological level OT induces milk ejection.[4] The treatment with a high supraphysiological dosage of OT is considered to allow a maximum udder emptying to remove the pathogens from the infected quarter together with the milk.[5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
