Effect of Sericea Lespedeza Hay on Gastrointestinal Nematode Infection in Goats

Gastrointestinal nematode (GIN) parasitism is the greatest threat to economic sheep and goat production in the southern USA, and there is widespread prevalence of GIN resistance to broad-spectrum anthelmintics in this region. A natural alternative for controlling GIN in small ruminants is feeding hay of sericea lespedeza [SL, Lespedeza cuneata (Dum.-Cours. G. Don)], a perennial warm-season legume high in condensed tannins. To determine the level of SL needed to reduce GIN infection, a confinement study was completed with 32 Spanish/Boer/Kiko cross yearling bucks offered one of four diets with 75% hay and 25% concentrate (n = 8, two pens per treatment, 4 goats/pen). The hay portion of each diet consisted of a combination of ground SL (0,25,50, and 75% of the diet) and bermudagrass [BG, Cynodon dactylon (L.) Pers.; 75, 50, 25, and 0% of the diet]. The bucks were allowed to acquire a natural GIN infection on pasture prior to moving to the pens. After a 3-wk adjustment period, the goats were stratified by fecal egg count (FEC) and packed cell volume (PCV), randomly assigned to treatments and pens, and then fed the treatment diets for six weeks. During the experimental period, fecal and blood samples were collected from individual animals weekly to determine FEC and PCV, respectively. Goats fed SL hay at 25, 50 and 75% of the diet had lower (P<0.05) FEC than control animals (75% BG hay), with a greater reduction as percent SL in the diet increased. There was also a dose response for PCV, with 75% SL-fed goats tending to have higher (P<0.10) PCV than the 25% SL and control animals, while the 50% SL goats were intermediate. The optimum level of SL hay in the diet for reducing GIN infection of small ruminants appears to be 50-75%, with some benefit even at 25% of the diet. Ground SL hay has potential as a natural supplement to or replacement for chemical anthelmintics. Introduction: Demand for goat meat and milk products is increasing in the USA, particularly in large metropolitan areas. Goat production is a growing industry in the Southeast, but infection with GIN, particularly the blood-feeder Haemonchus contortus, seriously threatens the industry. Since their introduction in the 1960s, broad-spectrum synthetic anthelmintics have been the primary defense against GIN infection in small ruminants in the USA and 'Graduate student, Research Professional, graduate student, Fort Valley State University, Fort Valley, GA 31030; Professor, Louisiana State University, Baton Rouge, LA 70803; Assistant Professor, Associate Professor, Fort Valley State University, Fort Valley, GA 31030; Research Animal Scientist, USDAIARS/DBSFRC, Booneville, AR 72927; Associate Professor, The University of Georgia, Athens, GA 30602; Professor, Auburn University, Auburn, AL 36849.