[Neutrophil defense against bovine uterine infections]

The killing ability of bovine peripheral blood neutrophils did not vary during the oestrous cycle. Administration of sex steroids to ovariectomised cows reduced the intrinsic killing ability of neutrophils but enhanced the opsonising ability of serum. Exudate from experimental uterine infection with Corynebacterium pyogenes and Fusobacterium necrophorum impaired neutrophil function, probably as a result of the action of bacterial leucotoxins.