Acquired resistance to experimental Heterakis gallinarum infections in pheasants: Relative immunity conferred by exposure to heterakids of different ages

Abstract

AbstractRing-necked pheasants were exposed to artificially limited 10-day infections with heterakids either from 0-10 or 10–20 days old. The number and length of worms developing from a subsequent challenge dose were compared with those in nonimmunized control birds and with those in birds that had been exposed to a continuous immunizing infection for a total of 49 days: 28 days before challenge and 21 days during the challenge infection.