The effect of sulfaquinoxaline feed medication on the immunologic response to a Pasteurella multocida vaccine administered to turkeys via drinking water.

Five groups of turkeys received C.U. strain Pasteurella multocida vaccine in the drinking water for one day. One group received the 0.1% level of sulfaquinoxaline feed medication at the time of vaccination, while 4 other groups received the feed medication 1, 2, 3 and 4 days after vaccination, respectively. Two weeks after vaccination all groups were exposed to a virulent P-1059 strain of P. multocida by the drinking water route. The results suggest that turkeys on the feed medication at the time of vaccination and possibly those receiving the initial fed medication the next day, failed to experience a satisfactory immunologic response. The possible ill effects of the sulfaquinoxaline feed medication on the duration of the immunity was not determined. A schedule and level of feed medication approved by the Food and Drug Administration was used; namely, 2 days on the 0.1% level, 3 days on a normal ration, and then 2 additional days on the 0.05% level of sulfaquinoxaline feed medication.