Date of Award

2009

Degree Type

Thesis

Degree Name

Master of Science in Fisheries, Animal and Veterinary Science

Department

Fisheries, Animal and Veterinary Science

First Advisor

Katherine Petersson

Abstract

The effect of parenteral administration of vitamin E during the pregnancy and lactation period of ewes and their lambs on innate and humoral components of the immune system was investigated in a 3 part study. 1.) Pregnant/Lactating ewes: Fifteen pregnant Dorset sheep were supplemented with vitamin E (30 IU d-α-tocopherol /Kg body weight (BW), E, n=l0) or placebo (emulsified base, P, n=5) from the last trimester of gestation through weaning. Blood and colostrum were analyzed every 2 wk for α-tocopherol, selenium, glutathione peroxidase activity, lysozyme activity, total IgG and IgG antibodies against tetanus toxoid. 2.) Lambs (0-8wks): Lambs born to E and P supplemented ewes received either vitamin E (30 IU d-α-tocopherol /Kg BW) or placebo (emulsified base) every 2 weeks from birth through 8 wk of age. This resulted in four treatment groups: E/E (n=l0), E/P (n=l1), PIE (n=4), PIP (n=5). The lambs were sampled every other week and their blood was analyzed as for the ewes. 3.) Lambs (Vaccination period): When the youngest lamb reached 8 wks of age all lambs were vaccinated as a group against Clostridium perfringens and Clostridium tetani. Booster vaccinations were given 4 wk later. Blood was sampled prior to primary vaccination, 1 wk post vaccination and then every 2 wk until 7 wk post vaccination. Results: Pregnant/Lactating ewes: Serum vitamin E concentrations increased over time in supplemented ewes as compared to placebo ewes. Colostrum vitamin E levels were also increased in supplemented versus placebo ewes. Vitamin E supplementation did not influence plasma selenium, glutathione peroxidase activity and serum lysozyme, IgG and IgG against tetanus toxoid in the serum or colostrum of ewes. There were fluctuations within treatment in the production of IgG in response to parturition. Lambs (0-8wks): Lambs directly supplemented with vitamin E in addition to maternal supplementation (E/E) had higher levels of serum a-tocopherol than the placebo group (PIP). There were no differences in plasma selenium, glutathione peroxidase activity, serum lysozyme, IgG and IgG against tetanus toxoid concentrations between groups. There was a loss of maternal antibodies over time in all lambs. Serum lysozyme activity was higher at birth, prior to ingestion of colostrum, in lambs that received maternal vitamin E supplementation compared to the lambs that received only direct vitamin E supplementation. Lambs (Vaccination period): Serum a-tocopherol levels increased in lambs that received direct vitamin E supplementation (E/E and PIE) irrespective of maternal supplementation (PIP and EIP). Plasma selenium, glutathione peroxidase activity, serum lysozyme and IgG did not differ between treatment groups. There was an increase in the production of IgG against tetanus toxoid in response to booster vaccination in PE lambs. Conclusions: Supplemental vitamin E to the ewes and lambs, at 30 IU/Kg BW, had a modest effect on parameters used in this study to assess innate and humoral immunity.

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