The effects of feeding sericea lespedeza hay on growth rate of goats naturally infected with gastrointestinal nematodes

¹ Agricultural Research Station, Fort Valley State University, Fort Valley, GA 31030
² Department of Agronomy and Soils, Auburn University, Auburn, AL, 36849
³ Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803
⁴ USDA/ARS/DBSFRC, Booneville, AR 72927

^* To whom correspondence should be addressed. E-mail: terrillt{at}fvsu.edu.

	Abstract

Goat production is increasing in the United States due to high ethnic demand, but infection with gastrointestinal nematode (GIN) parasites 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). An experiment was designed using infected and dewormed male kids (Kiko x Spanish, 6 mo old, 18.9 ± 3.25 kg) fed diets containing 25% concentrate and either 75% sericea lespedeza [SL; Lespedeza cuneata (Dum-Cours.) G. Don], a high CT forage (87 to 181 g of CT/kg), or 75% bermudagrass [BG; Cynodon dactylon (L.) Pers.] hay (n = 10/treatment). The kids were weighed every 14 d, and fecal and blood samples taken weekly for fecal egg counts (FEC) and packed cell volume (PCV) determination, respectively. Fecal cultures were processed every 14 d 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-N, and ruminal 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 by d 77. Average daily gain was greater (P < 0.001) in kids fed SL than BG-based diets, regardless of infection status (104.3 ± 5.0 and 75.5 ± 4.8 g/d, respectively). Total VFA and acetate concentrations were higher (P < 0.001) in the BG than in SL-fed goats, whereas propionate levels were unaffected by diet. Acetate:propionate ratio (P = 0.01) and plasma urea-N (P = 0.03) levels were higher in BG-fed goats, whereas rumen pH was higher (P < 0.001) in the SL-fed goats. Feeding SL hay can reduce GIN infection levels and increase performance of goats compared with BG hay.

Key Words: gastrointestinal nematodes, goats, growth, sericea lespedeza