Effects of condensed tannins on established populations and on incoming larvae of Trichostrongylus colubriformis and Teladorsagia circumcincta in goats

Abstract

-The use of tanniferous plants or tannins represents one alternative approach to the control of gastrointestinal parasites in ruminants but most data have been obtained in sheep. The current study was therefore performed in goats with two objectives: firstly, to investigate the effects of condensed tannins (CT) on adult populations of Trichostrongylus colubriformis and Teladorsagia circumcincta; secondly, to examine their effects on the establishment of infective larvae of these two species. In experiment 1, two groups of kids were infected with 6 000 L3 of T. colubriformis and 6 000 L3 of T. circumcincta. After 7 weeks, quebracho extracts were administered per os for 8 days to one group. A comparable group which did not receive tannins was included as the control. The kids were slaughtered on week 11. Parasitological and pathophysiological parameters were measured weekly. Worm counts were assessed and mast cells, globule leukocytes and eosinophils were counted in the abomasal and intestinal mucosae. Tannin administration was associated with a decrease in egg excretion, and a decrease in female fecundity, but with no changes in worm numbers. These changes were associated with an increased number of intestinal mast cells. In experiment 2, 24 goats were used according to a 2 ´ 2 factorial design, depending on infection and tannin administration. Two groups were either infected with 6 000 L3 of T. colubriformis or T. circumcincta. Within each group, the goats were either drenched or undrenched with tannin extracts. Pathophysiological parameters were measured weekly. Twelve days after the cessation of tannin administration, the goats were slaughtered. Worm counts and female worm fecundity were determined. Tannin consumption was associated with a significant reduction (P < 0.01) of Trichostrongylus populations and a close to significant reduction for Teladorsagia. No effect on fecundity was observed. Our results (1) confirm the consequences of condensed tannins on nematodes in goats as in sheep and (2) indicate divergent effects depending on the parasitic stage exposed to the condensed tannins.Trichostrongylus colubriformis / Teladorsagia circumcincta / goat / tannin / alternative methods of control

Anthelmintic effects of condensed tannins on Trichostrongylus colubriformis in experimentally infected sheep

“…Initially, animals from GII presented lower reduction, followed by GIII on the end of treatment period, confirming the potential use of taniniferous plants in the nematodes control. Many experiments correlated the CT uses with decrease of female helminthes fecundity (ATHANASIADOU et al, 2000a(ATHANASIADOU et al, , 2001aMIN;HART, 2003;PAOLINI et al, 2003aPAOLINI et al, , 2003b, standing out its importance in nematode epidemiology Despite the lower epg values from animals treated with CT in this study, the number of total worms presented in the intestines of sheep from different treatments was similar (P > 0.05). However, sheep treated twice with AE, which did not present the lower epg, showed a significantly lower number of nematode female.…”

“…The aim of this study was to confirm the potential use of CT as supplementation in ruminant diets, as prophylactic in parasite controls, as recommended by many authors (ATHANASIADOU et al, 2001a;NIEZEN et al, 2002a;PAOLINI et al, 2003a;GAILLARD;FRILEUX, 2005;MINHO et al, 2008a). Nevertheless, to correlate the CT consumption with a reduction of nematode eggs on pasture.…”

The anthelmintic efficacy of plant-derived cysteine proteinases against the rodent gastrointestinal nematode,Heligmosomoides polygyrus,in vivo

“…Indeed, we have already reported that anthelmintic activity against the stomach nematode, Protospirura muricola, is substantially increased when treatment is combined with antacids (Stepek et al 2007), but whether the same will be the case for worms in the small intestine is not yet known. Athanasiadou et al (2001) and Paolini et al (2003) reported that an extract of condensed tannins from plants reduced worm burdens of nematode species in the small intestine, but not of those in the abomasum, of small ruminants. A possible reason for this, as suggested by Athanasiadou et al (2001), could be the pH of the abomasum and small intestine.…”

Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode,Protospirura muricola,in vitroandin vivo

“…Our results regarding the treatment of mice with antacid prior to cysteine proteinase administration have confirmed, and added support to, the recent findings of Hale (2004), who found that when bromelain was administered with antacid, it retained its activity throughout the intestinal tract of mice. Importantly, Athanasiadou et al (2001) and Paolini et al (2003) reported that an extract of condensed tannins from plants reduced worm burdens of nematode species in the small intestine, but not of those in the abomasum, of small ruminants. The parallel to our results is clearly evident, especially as Athanasiadou et al (2001) suggested that a possible reason for this was the pH of the abomasum and small intestine.…”