Evolution of udder hygiene. Premilking teat sanitation.

Compared with post-milking teat dipping, predipping is in its infancy. Few controlled studies have been published on premilking teat disinfection/sanitation. Experimental challenge procedures resulted in consistent reductions for predipping compared with no udder preparation and conventional udder preparation, indicating a potential for effectiveness. Challenge studies that included the treatments of predip only and postdip only indicated that interactions during the milking process require elucidation. Positive benefits have been observed for predipping in field trials among some herds, but wide variation has been observed between herds in all field trial evaluations. Parity, DIM, and season of the year had major interactions on efficacy of predipping in Pankey et al's 1987 report; other trials have been of shorter duration and precluded analysis of these interactions. Interactions among these variables influenced incidence of mastitis by environmental pathogens. The length of time after milking before teats are contaminated probably is a major influence on predip efficacy. Predipping has reduced incidence of new IMIs and new cases of clinical mastitis. Unfortunately, certain factors negated these positive effects. These factors need to be defined. Producers should monitor effects of predipping to determine whether the investment in product and time has an economic return under the conditions of their dairy.