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

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 < 0.001) 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

Effets des tanins condensés sur le parasitisme par les nématodes gastro-intestinaux chez la chèvre

Le premier objectif de notre travail a été d'examiner chez les caprins, en conditions contrôlées, l'effet des TC sur les populations parasitaires installées et sur l'implantation des larves infestantes de Trichostrongylus colubriformis, Teladorsagia .circumcincta et Haemonchus contortus. Le principal résultat sur les populations installées a été une réduction fécale de l'excrétion des œufs de parasites associée à une diminution de la fertilité des vers femelles. Dans le second cas, les TC ont engendré une diminution de l'implantation du nombre de vers. Ces études ont mis en évidence des différences d'effets des tanins en fonction des espèces mais également des stades parasitaires.Une étude in vitro a été menée afin d'entamer un screening des effets de trois plantes ligneuses riches en TC : le chêne, le noisetier et les ronces, qui sont habituellement consommés par les caprins sur les nématodes modèle d'étude. Les effets du sainfoin, légumineuse fourragère, ont été testés afin d'avoir un élément de comparaison avec les légumineuses fourragères. Les larves infestantes ainsi que les vers adultes ont été affectés par les tanins des extraits de plantes.Dans un but plus appliqué, deux études ont été menées pour évaluer les conséquences de l'ingestion de foin de sainfoin chez des caprins naturellement infestés. L'excrétion fécale des œufs a été réduit dans les deux cas. Le second cas a mis en évidence une diminution des vers femelles des trois espèces majeures ainsi qu'une diminution du nombre de vers intestinaux. Une meilleure résilience des chèvres consommant le sainfoin a été observée.The first objective of the study was to examine, on goats, in controlled conditions, the effects of condensed tannins (CT) on established parasite populations and on the establishment of infective larvae of Trichostrongylus colubriformis, Teladorsagia .circumcincta and Haemonchus contortus. The main result on the established populations was a decrease in egg excretion associated with a dimininution of the fecundity of the female worms. In the second case, the CT provoked a reduction of the implantation of the worms. These studies have permitted to show differences of effects of CT according to the parasite species and the parasitic stages. An in vitro study was realized in order to screen the effects of three woody plants rich in CT: hazel tree, oak and brambles, usually consumed by goats on the model nematodes. The effects of sainfoin were also tested, a forage plant, in order to have a comparison with others leguminous forages. The infective larvae and the adult worms were affected by the plant extracts. Two applied researchs were performed in order to examine the consequences of ingestion of dry sainfoin by naturally infected goats. Egg excretion was decreased in the two cases. In the second study, the fertility of the female worms and the number of intestinal parasites were decreased. A better resilience was also observed in the sainfoin group.PERPIGNAN-BU Sciences (661362101) / SudocSudocFranceF

Effets des tanins condensés et des plantes à tanins sur les strongyloses gastro-intestinales chez le mouton et la chèvre

Les strongyloses gastro-intestinales sont une des pathologies majeures chez les petits ruminants. Une méthode alternative de lutte est l'emploi de tanins condensés. Les plantes riches en tanins peuvent être des plantes ligneuses telles que le noisetier, le châtaigner..., des plantes fourragères telles que le lotier corniculé, le lotier pédonculé, le sainfoin... Les tanins peuvent également se trouver au niveau des fruits (glands...). Des études réalisées chez les caprins et ovins ont permis de mettre en évidence que la consommation de plantes riches en tanins avait un effet sur la capacité de l'animal à lutter contre les strongyloses gastro-intestinales, mais aussi sur sa capacité à maintenir un niveau de production malgré la présence du parasitisme. Cependant, il subsiste quelques interrogations quant à leur utilisation (préciser l'effet des tanins sur les animaux laitiers, déterminer la dose optimale d'utilisation en élevage, choix de la meilleure source de tanins...). Ces techniques sont applicables en agriculture biologique

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

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 $\times$ 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

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

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 $\times$ 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

Administration of Duddingtonia flagrans chlamydospores to goats to control gastro-intestinal nematodes: dose trials

The ability of the nematophagous fungus Duddingtonia flagrans to reduce the number of infective nematode larvae in coproculture was investigated in goats using different doses of chlamydospores (0, 1.25 × 105, 2.5 × 105, 5 × 105 chlamydospores/kg BW/day) given by oral administration or by voluntary consumption in feed during natural or experimental infections with nematodes. The kinetics of excretion of D. flagrans chlamydospores in the faeces was also determined using a dose of 5 × 105 chlamydospores/kg BW/day for five days. For all the trials, the faecal nematode egg outputs were determined by a modified McMaster method and standard coprocultures were set up (14 days, 25 °C) to determine the number of larvae emerging from culture in fungus treated and control faeces. When chlamydospores were orally administered, the number of larvae were reduced by 50 to 97% when compared to control cultures. No difference in the level of larval emergence from the culture was seen for experimental or natural infections at the different chlamydospore dose rates. In contrast, when chlamydospores were distributed in the feed, a dose-dependent relationship was observed 10 days after the start of administration, the larval development being 2.0%, 14.0% and 86.9% for 5 × 105, 2.5 × 105 and 0 spores/kg BW/day, respectively. In addition, the kinetic study showed that the larval emergence from coproculture in the fungus group was statistically lower than in the control group from the second day of administration of the chlamydospores and remained lower until the second day after the last administration (p < 0.05). The results indicate that, for goats in farm conditions, a minimum daily dose of 5 × 105 chlamydospores/kg BW must be used to ensure a high treatment efficacy and that daily administration is preferable for maintenance of efficacy over time

USE OF TANNIN RICH PLANTS FOR THE CONTROL OF GASTROINTESTINAL NEMATODES IN SMALL RUMINANTS IN ORGANIC FARMING SYSTEMS.

Gastrointestinal nematodes represent one of the main threat associated with the use of pastures by grazing small ruminants. In organic farming systems, the use of chemical treatments to control these parasitic diseases remain strictly limited. There is thus a need to explore novel, alternative approaches to complement or replace the action of chemical anthelmintics. This seek for novel solutions is also widely required in other farming systems, because of the widespread diffusion of anthelmintic (AH) resistance within worm populations and because of the increasing concern of consumers on drug residues in animal products

Le genre des controverses

Le Dossier analyse des controverses autour du genre et montre les transformations idéologiques et la redéfinition d’antagonismes politiques à partir de dispositifs médiatiques qu’elles impliquent. Un point final est mis aux Échanges sur une sociologie des valeurs. Les Notes de recherche s’intéressent à l’usage des stéréotypes dans la communication interculturelle, à la presse privée égyptienne, à la construction-circulation des cadrages médiatiques de deux groupes d’extrême droite, à l’altération identitaire dans la fiction et à un nouveau modèle éditorial dans l’industrie DVD. En VO, sont étudiés des usages nouveaux des smartphones par des réfugiés syriens en Turquie. Le Focus est mis sur Médiarchie d’Yves Citton et sur La Raison graphique de Jack Goody. Les Notes de lecture rendent compte de plus de 50 publications. This Issue analyses gender controversies and show the ideological transformations and the redefinition of political antagonisms by media dispositifs they involve. The Exchanges on values sociology end. The Research Notes cover the use of stereotypes in intercultural communication, the Egyptian private press, the building and flow of media framings of two right-wing extremist groups, the identity fluctuations in fictional devices and a new publication model in the DVD industry. In Original Version, are examined new uses of smartphones by Syrian refugees in Turkey. The Focus is on Médiarchie by Yves Citton and on The Domestication of the Savage Mind by Jack Goody. The Book Reviews offer succinct overviews and analyses of publications in the field of information and communication