Effect of calf age and administration route of initial multivalent modified-live virus vaccine on humoral and cell-mediated immune responses following subsequent administration of a booster vaccination at weaning in beef calves.

Objective: To compare immune responses following modified-live virus (MLV) vaccination at weaning after intranasal or SC administration of an MLV vaccine to beef calves at 2 or 70 days of age.

Animals: 184 calves.

Procedures: Calves were allocated to 1 of 5 groups.

Evaluation of the ability of aqueous black walnut extracts to induce the production of reactive oxygen species.

Objective: To assess the in vitro capability of aqueous black walnut extracts (BWEs) to generate reactive oxygen species in water-based media ranging in makeup from a simple buffer solution to a complex solution containing serum.

Sample: 3 BWEs.

Procedures: Production of reactive oxygen species by BWEs prepared in water or N-hexane was tested in PBS solution, PBS solution containing 0.

Effect of maternal cells transferred with colostrum on cellular responses to pathogen antigens in neonatal calves.

Objective: To assess the effect of maternal cells or cellular components on neonatal immune responses to intracellular pathogens in calves.

Animals: 15 Holstein calves.

Procedures: Calves were fed whole colostrum, frozen colostrum, or cell-free colostrum within 4 hours after birth.