Identifier

etd-04072006-101332

Degree

Master of Science (MS)

Department

Veterinary Medical Sciences - Pathobiological Sciences

Document Type

Thesis

Abstract

Extracts of adult Haemonchus contortus were purified and used as a vaccine against the blood feeding parasite in goats as previously studied in sheep. The proteins used were H11 and H-gal-GP, hidden gut antigens from the microvillar membrane of the gut of the worm and combined with Quil A as adjuvant, then administered to a group of goats kept on concrete then artificially infected with H. contortus. The control group received Quil A injections and also infected. This study was performed to analyze the effects of the H11/H-gal-GP vaccine when given to goats as compared to sheep. The trial showed that IgG levels peaked three weeks after the first vaccine and remained high throughout the remaining booster series but began to wane after artificial infection. However, the IgG levels remained significantly higher than in the controls throughout the entire study. Overall mean fecal egg counts (FEC) were significantly higher in the controls and packed cell volume levels were significantly higher in vaccinated goats compared to controls from Week 3 post infection to the end of the study. A booster vaccine given Week 7 pi caused a sharp increase in IgG levels, elimination of worm burdens and decrease in FEC in the vaccinated group. 96% fewer H. contortus adults recovered at necropsy in vaccinated group compared to controls and >96% reduction in FEC after booster vaccine given during established infection. This study shows that the H11/H-gal-GP vaccine was sufficient in protecting goats after challenge infections but is shorter lived than when given under the same conditions in sheep. Booster vaccine given when infection levels are rising are effective in eliminating infections, reducing FEC and therefore may be used in place of an anthelmintic to control haemonchosis in goats as in sheep.

Date

2006

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

James E. Miller

DOI

10.31390/gradschool_theses.773

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