Date of Award

2023

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Biological and Environmental Sciences

First Advisor

Maria Peterson

Abstract

Gastrointestinal nematodes (GIN) are a major health concern globally, particularly for small ruminant producers. The most deadly of these GIN is an anemia-inducing parasite called Haemonchus contortus. Infections of H. contortus are most severe during what's known as the periparturient period (PPP), which is the last 6 weeks of gestation and first 8 weeks of lactation in maternal animals. Widespread genetic resistance of H. contortus to the traditionally used chemical dewormers have led producers and researchers alike to turn to the plant kingdom for answers. Plant based compounds have been used as bioactive compounds for centuries to cure a wide range of metabolic, physiological, and physical ailments. Recently, plant secondary compounds, specifically polyphenols such as proanthocyanidins (PAC) and tannins (CT), have demonstrated success in suppressing GIN infections. Although the mechanisms of these reactions are not well understood, antiparasitic efficacy has been demonstrated both in vivo and in vitro. Work from our lab group has shown both in vivo anthelmintic activity of cranberry vine PAC aqueous extracts (CV-PACaq) and in vitro suppression of fecal egg counts (FEC) and packed cell volumes (PCV), both of which are clear indicators of H. contortus infection. In this thesis we studied the effect of a 50% cranberry vine based pellet (CVP) on periparturient ewes and their offspring. By examining the milk, body weight (BW), FEC and PCV of the ewes, the BW, a variety of growth factors, and proteomics of the lambs, as well as a number of various circulating factors and metabolomics analysis, we hope to develop a more clear understand of the effects of the CVP on the overall health and well-being of these animals. Overall, the results from the variety of trials conducted throughout this thesis showed that the CVP had no effect on ewe BW or any lamb BW or growth parameters. There were observed effects of the CVP on a variety of milk components, circulating factors, proteins, and metabolites. All observed effects led to similar conclusions, that the CT and PAC levels in the CVP had many antioxidant effects on the animals metabolic stress levels but the high copper content of the pellet may be impairing the liver functionality and impacting the ewes milk quality. More research is needed to determine the exact bioactive compounds within the cranberry vine and understand the metabolic compounds that the lambs could be receiving through the milk. In the future, it might be more beneficial to conduct this research in a less copper sensitive species, such as goats.

Creative Commons License

Creative Commons Attribution-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-No Derivative Works 4.0 License.

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