- Animals: sheep
- Pest Management: biological control, disease vectors
In this study, AUGrazier sericea lespedeza (AUGSL) leaf meal pellets which have a higher concentration of condensed tannin, was evaluated, as a supplement pelleted feed, for affect on naturally acquired Haemonchus contortus infection in grazing ewes. The study had 2 phases, one during parturition/lactation and another during summer grazing. Results indicated that suplementation did not affect fecal egg count (FEC), blood packed cell volume (PCV), FAMACHA score or survival/developement of larvae in feces during the peri-parturient period. During the summer grazing period, there was no effect on FEC, PCV or FAMACHA, but there was a reduction of larval survival/development in feces. For both periods there was a reduction in survival/development of Haemonchus larvae in AUGSL leaf meal supplemented ewes. Results were disseminated to scientific and producer groups via producer workshops, the Southern Consortium for Small Ruminant Parasite Control web page (SCSRPC.org), and various scientific and extension publications.
Infection with gastrointestinal nematode (GIN) parasites, particularly Haemonchus contortus, a blood-feeder, is the most important constraint to profitable small ruminant production in the southeastern US and worldwide. Weanlings are especially susceptible to infection during their first grazing season. Infection with H. contortus can rapidly lead to lost production and even death. Over use of anthelmintics (dewormers) has resulted in high levels of dewormer resistance in GIN throughout the southeast and other regions where H. contortus is a problem. The problem has become so severe that it is threatening viability of small-scale and limited-resource small ruminant farm operations in this region despite continued high demand for sheep and goat products. A more sustainable approach to parasite control involves integrating targeted, limited use of anthelmintics with non-chemical alternative control methods that reduce GIN numbers in the host animal and lower pasture contamination with eggs and larvae. Grazing sericea lespedeza [a condensed tannin containing forage] and feeding whole plant (AUGrazier cultivar) hay and pellets in confinement has been shown to effectively reduce GIN infection in sheep and goats.
Determine the effect of AUGSL leaf meal pellets, fed as a supplement, on Haemonchus contortus infection in grazing ewes during the parturition/lactation and summer grazing periods.