Condensed tannins effect on gastrointestinal nematodes of small ruminants

Abstract

In order to evaluate the anthelmintic effect of condensed tannins (TC), a study was made to evaluate its effect on gastrointestinal nematodes (NGI) in goats and sheep. Two groups of 6 goats and 4 sheep grazing Lucerne were assigned; one group without treatment (GST) was daily supplemented with ground corn (500 g), while the other group (GTC) with the same diet and the inclusion of 25 g of TC. Faecal nematode egg counts (epg) and coprocultures were made every two weeks for 3 months. In addition, FAMACHA technique and body condition score (CC) were recorded. The epg were similar in the first three samplings (mean= 507.4 GTC y 351.4 GST), then the GST epg decreased being lower than those of the GTC, but without significant differences (p <0.096) between groups, between sampling dates (p <0.66) not even in group per sampling date interaction (p <0.99). From faecal cultures Haemonchus (64.6%) predominated in GTC and Trichostrongylus (45.8%) in GST; Teladorsagia was recovered under low percentages. FAMACHA score did not show differences (p <0.46) between groups, averaging 2.11 ± 0.66 and 1.83 ± 0.71 respectively for GTC and GST. The CC averages were 2.93 ± 0.65 and 3.16 ± 0.54 respectively for GTC and GST and differences weren’t found (p <0.42). It concluded that under the conditions of this study with low NGI burdens, the condensed tannin dose of 25g in 500g of corn represents a low dose without anthelmintic effect.