PSXII-27 - Effects of Sericea lespedeza on methane emission and health status in grazing Boer goat wethers

The objective was to determine effects of feeding 12 yearling Boer goat wethers Sericea lespedeza as supplemental pellets or grazed forage on ruminal methane emission and health status compared with grazing grass-based pasture and supplemental forage-concentrate pellets. There were 4 5-wk periods in the late spring and summer. Periods 1-3 were on a 0.7-ha native grass pasture and period 4 was on a 1.1-ha pasture of Sericea lespedeza. A forage-concentrate pellet was supplemented in period 1 (CON1), 3 (CON2), and 4 (SL-P), and pelleted Sericea lespedeza (Sims Brothers Inc., Union Springs, AL) was given in period 2 (SL-S). Pellets were supplemented and ruminal methane emission was measured with a small ruminant GreenFeed unit (C-Lock, Rapid City, SD). Pellets were dispensed up to 30 times daily, with 6 sessions of 5-9-g bait drops and a 2.5-h session interval. Body weight at the end of periods generally increased as period advanced (35.7, 38.8, 37.9 and 41.1 kg for CON1, SL-S, CON2, and SL-P, respectively; SEM=1.08). Sericea lespedeza decreased methane emission (P < 0.05), with pasture grazing having greater effect than pellet supplementation (43.7, 36.2, 40.9, and 32.5 g/d for CON1, SL-S, CON2, and SL-P, respectively; SEM=0.84). Likewise, SL consumption decreased FAMACHA score (P < 0.05), with a similar effect for both SL forms (3.28, 2.95, 3.21, and 2.86 for CON1, SL-S, CON2, and SL-P, respectively; SEM=0.061). Body condition score was similar among periods (2.65, 2.64, 2.68, and 2.67 for CON1, SL-S, CON2, and SL-P, respectively; SEM=0.022). In conclusion, the effect of consumption of SL on methane emission probably relates to condensed tannins and greater impact of SL-P could involve a higher dietary level. Similarly, inclusion of SL in meat goat diets has potential to decrease the parasite load and thereby improve health status, also presumably because of bioactive condensed tannins.