title: Machine-induced teat tissue reactions and infection risk in a dairy herd free from contagious mastitis pathogens.
abstract: Machine-induced changes in teat thickness were measured in a randomly selected group of 22 cows from a commercial dairy herd consisting of 110 cows during an experiment lasting 1 year. Half the cows used were free from mastitis whereas the remainder had at least one quarter infected by environmental pathogens. Teats were classified according to a threshold change in teat end thickness of 5%. The relationships between quarter infection or teat duct colonization and teat end thickness changes induced by machine milking were investigated. Teats with greater than 5% change in thickness had significantly increased teat duct colonization and a slight, non-significant, increase in quarter infection. We conclude that machine-induced changes in teat end thickness are predisposing factors for teat duct colonization by environmental pathogens. This may provide an increased new infection risk, especially when hygiene is poor.
authors.affiliation: Istituto di Malattie Infettive, Università degli Studi di Milano, Italia.
authors.forename: A
authors.initials: A
authors.lastname: Zecconi
authors.forename: J
authors.initials: J
authors.lastname: Hamann
authors.forename: V
authors.initials: V
authors.lastname: Bronzo
authors.forename: G
authors.initials: G
authors.lastname: Ruffo
mesh_terms: D000818:Animals; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D002417:Cattle; D003612:Dairying / Q000379:methods*; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000382:microbiology / Q000473:pathology*; D008414:Mastitis, Bovine / Q000209:etiology* / Q000382:microbiology / Q000473:pathology; D013291:Streptococcus / Q000302:isolation & purification