Project title: Anthelmintic efficacy of pelleted cranberry vine against larval development of Haemonchus contortus
Mentors: Carly Barone and Katherine Petersson, PhD
Abstract: Haemonchus contortus (barber pole worm) is the most pathogenic species of gastrointestinal nematode infecting small ruminants such as sheep and goats. Overuse of commercial deworming medications, has led to the development of resistance in H. contortus and other gastrointestinal nematodes (GIN) of small ruminants. Previous research has focused on exploring the efficacy of using forages that contain condensed tannins—compounds that have demonstrated anti-parasitic activity—as an alternative method for treating GIN infection. Cranberry vine (CV) is a condensed tannin containing plant native to the New England region. In vitro studies in this laboratory have demonstrated an anti-parasitic effect of CV against the barber pole worm. The objective of this study was to determine the anti-parasitic efficacy of egg hatch of H. contortus in the feces of lambs fed a pelleted cranberry vine supplement. Cranberry vine prunings were obtained in the spring of 2015, as the cranberry vines came out of winter dormancy. The CV was incorporated into a feed pellet and fed to 5 month old lambs for 8 weeks (CV, n=7; control, n=7). Lambs were subjected to a trickle infection of H. contortus (500 larvae 3/week) from week 3 to 5 of supplementation. Fecal samples were collected weekly to determine fecal egg counts and used to create a composite fecal culture for each group of lambs. The composite cultures were analyzed to determine hatchability and larval viability of eggs hatched. There was no significant reduction in hatchability or viability for larvae exposed to the cranberry vine. It is possible that the lack of an anti-parasitic effect, in contrast to that seen in the in vitro work, could be attributed to complexing of the tannins during the pelleting process or an insufficient supplementation period. Future work could include an additional feeding trial lasting longer than eight weeks and a different form of the cranberry vine used for feeding.