2013 Annual Report
1a.Objectives (from AD-416):
The objectives of this project are to optimize control of gastrointestinal worms of sheep and goats by supplementation with pelleted sericea lespedeza leaf meal, determine the effect of the pellets on coccidiosis, and determine the impact of the pellets on gastrointestinal worm infection of free range poultry. In addition, the impact of harvesting sericea lespedeza at different times during the summer and under various conditions on leaf meal quality will be determined.
1b.Approach (from AD-416):
Harvest treatments at several locations across the southeastern U.S. will be imposed on established sericea lespedeza similar to what could be encountered on farm. Forage quality traits and condensed tannin content will be measured on dried samples. In Arkansas and Georgia, lambs and kids will be randomly assigned to a supplement of alfalfa or 75% sericea lespedeza leaf meal pellets fed at a high or moderate rate of gain for 12 weeks. In Arkansas, Georgia, and Louisiana, goat kids and lambs will be used to examine the effect of sericea lespedeza pellet supplementation on control of coccidia. Animals will be randomly assigned to receive 2% of body weight per day of alfalfa pellets (control) or the sericea lespedeza leaf meal pellet described above with or without a coccidiostat. In Arkansas, lambs will graze grass pastures post-weaning and receive 2% of body weight per day of a 16% crude protein pellet containing 75% alfalfa (control) or sericea lespedeza. Fecal egg and oocyst counts and blood packed cell volume will be determined every 7 days throughout the sheep and goat experiments, and body weights will be determined every 14 days. In Arkansas, broilers (14 days of age) will remain uninfected, or be artificially infected with two challenge levels of Ascaridia galli larvae. Birds will be offered a control (alfalfa pellets) or sericea lespedeza pellets (75% sericea lesepedeza leaf meal pellet described above) at hatch or at 21 days of age to examine the effectiveness of sericea lespedeza pellets on preventing or controlling A. galli. Birds will be necropsied at day 40. The number of worms in the gastrointestinal tract will be quantified. Cloacal samples will be collected every 7 days for bacterial (Campylobacter and Salmonella) enumeration using 16S rRNA gene sequencing methods.
Scientists from the USDA, ARS Dale Bumpers Small Farms Research Center, Booneville, Arkansas; Louisiana State University; and Fort Valley State University are examining the effects of sericea lespedeza leaf meal pellets on the control of coccidiosis in lambs and goat kids, an economically devastating parasitic disease that affects livestock and poultry. Coccidiostats are often ineffective and are not allowed in organic production. Condensed tannins from sericea lespedeza reduced the number of protozoan parasite (Eimeria spp.) oocysts found in the feces of lambs and kids and reduced the clinical signs of coccidiosis. Reduction of coccidiosis will increase feed efficiency and reduce death loss of livestock. Concurrently, these scientists are examining long-term feeding of sericea lespedeza to aid in the control of gastrointestinal nematodes in sheep and goats. Gastrointestinal nematodes are the greatest threat to the health of young lambs, kids, and adult females around the time of parturition. Dewormer resistance means many commercial drugs are ineffective. Incidence of deworming is reduced in sericea lespedeza-fed animals; however, long-term feeding may affect mineral availability to the animal. An understanding of how this impacts the animal is currently under investigation. In addition, experiments have been conducted to examine the mineral status of sheep and goats consuming sericea lespedeza pellets and long-term body weight changes. Experiments are being conducted in poultry in collaboration with USDA, ARS Poultry Production & Product Safety Research Unit in Fayetteville, Arkansas, to determine the impact of sericea lespedeza on parasites. Data has been compiled on management practices of sericea lespedeza to harvest leaves for leaf meal, including the date of cutting and the order of cutting (first, second, third), to determine the possible effect on nutrients and condensed tannins.