ARS | Publication request: The effects of feeding sericea lespedeza hay on growth rate of goats naturally infected with gastrointestinal nematodes

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 25, 2008
Publication Date: October 8, 2008
Citation: Moore, D., Terrill, T., Kaouakou, B., Shaik, S., Mosjidis, J., Miller, J., Vanguru, M., Kannan, G., Burke, J.M. 2008. The effects of feeding sericea lespedeza hay on growth rate of goats naturally infected with gastrointestinal nematodes. Journal of Animal Science. 86:2328-2337.

Interpretive Summary: Widespread resistance of gastrointestinal worms to chemical dewormers has led to the need for alternative parasite control. Plants containing condensed tannins, such as sericea lespedeza, have anthelmintic properties, but growth rate while growing kids consume this forage is unknown. Scientists at Fort Valley State University, Auburn University, Louisiana State University and USDA, Agricultural Research Service determined that sericea lespedeza hay maintained anthelmintic activity when fed to goats and gains were better than bermudagrass hay because of increased intake. These results indicate that sericea lespedeza hay aids in the control of internal parasites in goats and promotes growth, which is important to extension agents, scientists, and a growing number of goat producers.

Technical Abstract: Goat production is increasing in the United States due to high ethnic demand, but infection with gastrointestinal nematodes (GIN) is a major constraint to the industry. Increasing GIN resistance to chemical anthelmintics world-wide has led to the development of alternative control strategies, including use of forages containing condensed tannins (CT). Sericea lespedeza [SL, Lespedeza cuneata (Dum-Cours.) G. Don], a high CT forage, has been shown to reduce GIN levels in goats using long stem, ground and pelleted hay forms, but little is known about its effect on growth rate in young goats and on interactions between GIN infection level and nutrition. An experiment was designed using infected and non-infected male kids (Kiko X Spanish, 6 mo. Old, 18.9 ± 3.25 kg) fed diets consisting of 75% hay [SL or bermudagrass (BG; Cynodon dactylon (L.) Pers.)] and 25% concentrate (n = 10 per treatment). The kids were weighed every 2 wk, and fecal and blood samples taken weekly for fecal egg count (FEC) and packed cell volume (PCV) determination, respectively. Fecal cultures were processed every 2 wk to determine CT effect on larval development. At slaughter, adult GIN were collected from the abomasum and small intestines for counting and speciation. Blood samples were also analyzed for plasma urea nitrogen (PUN), and liver weight and ruminal volatile fatty acids (VFA) and pH were determined. The infected SL-fed kids had consistently lower (P < 0.05) FEC than the infected BG goats throughout the trial and higher (P < 0.05) PCV starting in wk 11. Average daily gain was higher (P < 0.001) in kids fed SL than BG-based diets. The SL infected and non-infected kids gained 101 and 109 g/d, respectively, compared with 74 and 79 g/d in BG-fed kids. Final weights were higher (P < 0.01) in SL than BG-fed kids, but there were no differences between treatment groups in weight loss due to pre-slaughter feed deprivation. Total VFA and acetate concentrations were higher (P < 0.001) in the BG than the SL-fed goats, while propionate levels were unaffected by diet. Acetate: propionate ratio and PUN levels were higher (P < 0.05) in BG-fed, while rumen pH was higher (P < 0.001) in the SL-fed goats. Feeding SL hay reduced GIN infection levels and increased animal performance compared with BG hay, suggesting that the CT in this plant had beneficial nutritional and anti-parasitic properties.