9 CFR §78.10

1. (a)Female dairy cattle born after January 1, 1984, which are 4 months of age or over must be official vaccinates to move interstate into or out of a Class B State or area 4 unless they are moved interstate directly to a recognized slaughtering establishment or quarantined feedlot, or directly to an approved intermediate handling facility and then directly to a recognized slaughtering establishment, or directly to an approved intermediate handling facility and then directly to a quarantined feedlot and then directly to a recognized slaughtering establishment, or directly to an approved intermediate handling facility and then directly to a quarantined feedlot and then directly to a recognized slaughtering establishment. Female cattle eligible for official calfhood vaccination and required by this paragraph to be officially vaccinated may be moved interstate from a farm of origin directly to a specifically approved stockyard and be officially vaccinated upon arrival at the specifically approved stockyard.
2. (b)Female cattle born after January 1, 1984, which are 4 months of age or over must be official vaccinates to move into a Class C State or area 4 unless they are moved interstate directly to a recognized slaughtering establishment, or directly to an approved intermediate handling facility and then directly to a recognized slaughtering establishment, or directly to an approved intermediate handling facility and then directly to a quarantined feedlot and then directly to a recognized slaughtering establishment. Female cattle eligible for official calfhood vaccination and required by this paragraph to be officially vaccinated may be moved interstate from a farm of origin directly to a specifically approved stockyard and be officially vaccinated upon arrival at the specifically approved stockyard.
3. (c)Female cattle born after January 1, 1984, which are 4 months of age or over must be official vaccinates to move interstate out of a Class C State or area 4 inder § 78.9(d)(3) of this part. Female cattle from a certified brucellosis-free herd that are eligible for official calfhood vaccination and required by this paragraph to be officially vaccinated may be moved interstate from a farm of origin directly to a specifically approved stockyard and be officially vaccinated upon arrival at the specifically approved stockyard.