title: Protecting chickens against coccidiosis in floor pens by administering Eimeria oocysts using gel beads or spray vaccination.
abstract: Control of avian coccidiosis is increasingly being achieved by the administration of low doses of Eimeria oocysts to newly hatched chicks. The purpose of this study was to test the efficacy of gel beads containing a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts as a vaccine to protect broilers raised in contact with litter. Newly hatched chicks were either sprayed with an aqueous suspension of Eimeria oocysts or were allowed to ingest feed containing Eimeria oocysts-incorporated gel beads. Control, 1-day-old chicks were given an equivalent number of Eimeria oocysts (10(3) total) by oral gavage or received no vaccine (nonimmunized controls). All chicks were raised in floor-pen cages in direct contact with litter. At 4 wk of age, all chickens and a control nonimmunized group received a high-dose E. acervulina, E. maxima, and E. tenella challenge infection. Chickens immunized with Eimeria oocysts in gel beads or by spray vaccination displayed significantly (P < 0.05) greater weight gain (WG) compared to nonimmunized controls. Feed conversion ratio (FCR) also showed a significant (P < 0.05) improvement in both groups relative to nonimmunized controls. Moreover, WG and FCR in both groups was not significantly different (P > 0.05) from chickens immunized by oral gavage or from nonimmunized, noninfected controls. Oocyst excretion after Eimeria challenge by all immunized groups was about 10-fold less than in nonimmunized controls. These findings indicate that immunization efficacy of gel beads and spray vaccination is improved by raising immunized chicks in contact with litter.
authors.affiliation: Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, ARS, USDA, Beltsville, MD 20705, USA. mark.jenkins@ars.usda.gov
authors.forename: Mark C
authors.initials: MC
authors.lastname: Jenkins
authors.forename: Carolyn
authors.initials: C
authors.lastname: Parker
authors.forename: Celia
authors.initials: C
authors.lastname: O'Brien
authors.forename: Joseph
authors.initials: J
authors.lastname: Persyn
authors.forename: Darren
authors.initials: D
authors.lastname: Barlow
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Miska
authors.forename: Raymond
authors.initials: R
authors.lastname: Fetterer
mesh_terms: D000818:Animals; D002645:Chickens; D003048:Coccidiosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D004539:Eimeria / Q000276:immunology / Q000502:physiology*; D016786:Eimeria tenella / Q000276:immunology / Q000502:physiology; D005430:Floors and Floorcoverings; D005780:Gelatin / Q000008:administration & dosage / Q000627:therapeutic use*; D006799:Housing, Animal; D033661:Oocysts / Q000502:physiology; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D015430:Weight Gain
chemical_list: D016052:Protozoan Vaccines; D014613:Vaccines, Attenuated; D005780:Gelatin