| Popis: |
Sixteen nulliparous Holstein heifers were exposed artificially to Brucella , abortus , biotype 1 strain 2308. Attempts were made to recover the organism from blood, udder secretions and cervical mucus. Blood cultures 2 to 4 wk postexposure were positive. B . abortus , was recovered from one or more udder quarters in 11 heifers. B . abortus , was recovered from cervical mucus of one heifer on Day 18 postexposure. All heifers were serologically positive within 5 wk. The presence of B . abortus , in the nongravid uterus is transitory and associated with the bacteremic phase. It is limited or prevented in most heifers due to the effect of estrus. Nulliparous heifers are suitable candidates for use as donors of Brucella -free embryos, even where infection is known to exist in the herd. |
