Date of Graduation

5-2018

Document Type

Thesis

Degree Name

Master of Science in Poultry Science (MS)

Degree Level

Graduate

Department

Poultry Science

Advisor/Mentor

Billy Hargis

Committee Member

Lisa Bielke

Second Committee Member

Guillermo Tellez

Keywords

Alpha-toxin, Antibody Titer, Clostridium Septicum, Oil-emulsion Vaccine, Turkey Cellulitis

Abstract

Alpha-toxigenic Clostridium septicum (CS), the cause of turkey cellulitis, results in devastating mortality with high costs for the industry. Various vaccinations have been evaluated to prevent this disease with moderate success. Ability of a CS bacterin-toxoid, in conjunction with adjuvants such as aluminum hydroxide, mannoslyated chitosan, or a water-in-oil Seppic Montanide 71 R VG adjuvant (OE) to induce immunity was evaluated in a 7-week study (Experiment 1). Poults (20/group) were vaccinated day-of-hatch, boosted at 5 weeks-of-age and compared to unvaccinated controls. Antibody titers were determined by ELISA for all experiments. In experiment 1, initial vaccination with OE resulted in significantly (P<0.05) higher antibody titers at 5 weeks-of-age, and at 7 weeks-of-age OE resulted in numerically increased antibody titers compared to all vaccinated groups. Efficacy of the OE vaccine was then evaluated in two field trials (Experiment 2 and 3) with treatments including a non-vaccinated control group and a vaccinated group. Non-vaccinates were marked by removal of the dewclaw at the hatchery and comingled during growout (Experiment 2 and 3). Experiment 2 consisted of 3 houses: House 1 (HS1), House 2 (HS2), and House 3 (HS3). Mortality associated with cellulitis was recorded once the first case was observed. Blood samples were obtained at 8, 12, and 16 weeks-of-age. Antibody titers (S/P ratio) in vaccinated groups for weeks 12 and 16 were significantly higher (P<0.05) than the control group for all 3 houses. In HS1 and HS2, low CS-associated mortality was observed and there was no significant difference in mortality/total (%) between control and vaccinated group. In HS3, unvaccinated mortality/total (%) was significantly (P<0.001) higher than mortality in vaccinated turkeys. Experiment 3 consisted of 6 farms with 1-4 houses/farm. Vaccination significantly (P<0.05) reduced CS-related mortalities as compared to controls in 5 of 6 farms in experiment 3 and antibody titers were significantly (P<0.05) higher in vaccinated turkeys at 12 and 16 weeks for all 6 farms. Based on these results, W/O emulsion vaccines, such as this alpha-toxin bacterin-toxiod with Montanide 71 R VG adjuvant, can be used to increase antibody titers and may reduce related mortalities in the field.

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