Efficacy of antisepsis measures during manual milking on the prevalence of bacterial Mastitis at the Sahelian experimental station of Toukounous, Niger

Abstract

Hygiene co onditions during milking g are essen ntial in dairy cattle to e ensure the h ighest leve el of milk production. . The aim of this work w was to asse ss the efficacy of hygi ne measure e s during the e manual milking pro cess with no o pre- or pos st-milking antisepsis me easure at the e Sahelian experimental s station of Toukounou s (Niger), on n the preval ence of Calif rnia Mastitis o s Test (CMT) )-positive cows, on the id dentity of bacterial pa thogens rec covered from positive m milk samples and on the e clonality of f the Staphy ylococcus aureus iso lated. The a application of mammary y gland was hing prior to milking, of teat dipp ping with chlorhexidi ne after mil king and of f milkers’ ha and washing and disinfe ection with sodium hyp pochlorite significantly decreased the number r of CMT-pos sitive cows. However, the e percentage es of bacteri ologically positive mil k samples a and the relat ive isolation rates of S. aureus and c coagulase-ne egative stap hylococci did not sign ificantly diff fer according to the pres sence/absen ce of antisep psis measure e. As for the e clonality of the S. au reus isolate es, the 53 S. aureus isol ted in the a a bsence of h hygiene meas sures belong ged to 10 pulsed field gel electro ophoresis (P FGE) fingerp prints, while , in compari ison, only fiv ve PFGE fin gerprints were ident ified among gst the 11 S. aureus i isolated in the presenc ce of hygie ene measur es. As a conclusion , the strict a application of hygiene a nd disinfect ion during h hand milking g at Toukou nous is a major cont ributor to th he decrease of the perce entage of CM MT-positive cows and, t therefore, o f mastitis prevalence and inciden nce. The reas sons for the persistence e of the remaining S. aur reus after ap pplication of hygiene measures m ay be nume rous; one of them could be that they y belong to more resistan nt clones.