Effects of teat dilators and teat cannulas on udder health

Abstract

Over a period of 15 days, the teats of 4 dairy cows were inserted with teat dilators, teat cannulae or were left untreated (controls). Cows were milked twice daily. Teat dilators were removed for milking. During milking time, the plugs of the teat cannulae were removed and milk was drained. All teats were examined using endoscopy before the start (day 0) and after the end (day 16) of this study. The California Mastitis Test (CMT) and bacteriological examination were performed on milk collected in the morning on days 0, 5, 11, and 16. The use of teat dilators and teat cannulae was associated with injuries and cisternitis. The character of these injuries indicated that teat dilators and teat cannulae pierce the teat cistern lining. In three of seven teats the removal of the teat cannula caused circular separation and eversion of the Frstenberg rosette and teat canal skin. The use of teat dilators and teat cannulae significantly increased CMT scores and the odds of a positive bacterial culture. It is concluded that the use of teat dilators and teat cannulae may harm udder health.