Location: Dale Bumpers Small Farms Research CenterTitle: Effect of sericea lespedeza leaf meal pellets on adult female Haemonchus contortus in goats
|KOMMURU, D - Fort Valley State University|
|WHITLEY, N - North Carolina Agricultural And Technical State University|
|MILLER, J - Louisana State University|
|MOSJIDIS, J - Auburn University|
|GUJJA, S - Fort Valley State University|
|MECHINENI, A - Fort Valley State University|
|TERRILL, T - Fort Valley State University|
Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/8/2014
Publication Date: 1/15/2015
Citation: Kommuru, D.S., Whitley, N.C., Miller, J.E., Mosjidis, J.A., Burke, J.M., Gujja, S., Mechineni, A., Terrill, T.H. 2015. Effect of sericea lespedeza leaf meal pellets on adult female Haemonchus contortus in goats. Veterinary Parasitology. 207:170-175.
Interpretive Summary: The inability to control barberpole worm (Haemonchus contortus), a blood-sucking stomach parasite, in sheep and goats due to dewormer resistance has led to the use of sericea lespedeza (SL) as an aid in the control of this parasite. The mechanism of action has not been described, but is associated with the condensed tannins in SL. Scientists at USDA, ARS in Booneville, AR, Fort Valley State University, GA, Louisiana State University, North Carolina A&T, and Auburn University discovered that feeding SL pellets to goats led to cuticular surface damage of the adult worm in the stomach. This information is important to scientists working with condensed tannin plants and alternatives for the control of barberpole worm.
Technical Abstract: Sericea lespedeza (SL; Lespedeza cuneata) is a perennial warm-season forage rich in condensed tannins (CT) that has been reported to have anthelmintic activity against small ruminant gastrointestinal nematodes (GIN), particularly Haemonchus contortus, a highly pathogenic blood-feeder, but the mechanism of action of CT against H. contortus is not clearly understood. Two experiments with young goats were designed to study the effect of SL leaf meal pellets on 1) a mature H. contortus infection, and 2) the surface appearance of adult H. contortus female worms. In Experiment 1, 36 female and castrated male Boer crossbred goats were fed 75% SL leaf meal pellets or alfalfa pellets (18 goats/treatment group) ad libitum in individual pens. All the goats were artificially infected with 5000 H. contortus L3–stage larvae over a period of 6 days six weeks prior to the start of the 28-day trial. Fecal and blood samples were collected weekly for fecal egg count (FEC) and packed cell volume (PCV) determination, respectively, and all goats were slaughtered at the end of the trial for adult GIN recovery and counting. In Experiment 2, five adult female H. contortus were recovered from the abomasum of two goats from each treatment group in Experiment 1 and from a study in which 75% and 95% SL leaf meal pellets or a commercial feed pellet were group-fed to grazing goats (270 days old, Spanish males, 10/treatment group) at 0.91 kg/head/d for 11 weeks. Adult GIN collected were fixed and examined for evidence of surface damage using scanning electron microscopy. Feeding 75% SL pellets to young goats in confinement reduced (P < 0.05) FEC compared with control animals in Experiment 1. Total worm numbers and PCV were not influenced by treatment. Of the 5 adult H. contortus recovered from goats in Experiment 1, 60% of the worms from treated goats had cuticular surface damage, while no damage was observed on worms from the control group. All five worms (100%) observed from the 75% SL leaf meal pellet and 95% SL leaf meal pellet treatment goats from the grazing study showed a disheveled cuticular surface, whereas this was not observed on worms from control animals. Overall, this work suggests that a possible mechanism of action of SL against H. contortus in the animal’s abomasum is a direct action of CT on the cuticle or possibly internal tissues of the female worm.