Environmental XXXX : cause, prevalence, prevention.

@entity883 @entity5967 @entity281 @entity1271 @entity291
Rate of intramammary infection by coliform bacteria and species of streptococci other than @entity5967 (environmental pathogens) was studied in a dairy herd in total confinement. Rate was higher during the dry period than during lactation and increased progressively as parity increased. Rate was maximal during summer and coincided with maximum exposure to coliforms in bedding. @entity883 were longer than coliform. Approximately 59% of @entity883 and 69% of @entity281 were present for 30 lactation days or less. Percent quarters infected by day of year varied between .7 and 3.0% for coliform bacteria and between 1.6 and 4.7% for streptococci. Approximately 81% of @entity281 and 53% of @entity883 during lactation were clinical. Clinical cases were highest during the first 76 days of lactation and during summer. Only 6.7% of @entity281 resulted in acute @entity1271 , and all acute cases were during summer or early lactation. Dry @entity291 therapy reduced rate of @entity883 during the early dry period but was without effect during the prepartum period. There was no effect of dry @entity291 therapy on coliform infection rate during the dry period. Problems associated with prevalence and control of environmental @entity1271 were discussed.
