Anthelmintic effect of carob pods and sainfoin hay when fed to lambs after experimental trickle infections with Haemonchus contortus and Trichostrongylus colubriformis.

Celia Arroyo-Lopez,Hervé Hoste,Nikolaos Voutzourakis,Foteini Manolaraki,Katerina Saratsi,Vasileios Skampardonis,Alexandros Stefanakis,Anastasios Saratsis,Smaragda Sotiraki

doi:10.1051/parasite/2014074

Abstract

The aim of the study was to compare the in vivo anthelmintic activity of sainfoin hay (Onobrychis viciifolia) and carob pod meal (Ceratonia siliqua) against gastrointestinal nematodes. Seven days before infection, 64 naive lambs were assigned to four different groups: Group S received sainfoin hay and group CAR was fed with carob pods. The remaining lambs received lucerne hay (Medicago sativa) and were assigned to positive (non-treated, NT) and negative (treated, T) control groups (treatment with albendazole). On day 0, lambs were artificially trickle infected for 6 weeks, with a mixture of infective larvae of Haemonchus contortus and Trichostrongylus colubriformis. Parasitological and pathophysiological parameters were measured repeatedly during the 2-month study. Compared to the NT group, decreases in egg excretion were observed in the CAR and S groups with significant differences only found for sainfoin (p < 0.05). At necropsy, group S showed decreases in the total worm numbers of both nematode species with significant differences for H. contortus. In contrast, no differences were noticed for the CAR group. Compared to the NT group, lower values for fecundity of female H. contortus were found in the S and CAR groups, however differences were non-significant. No differences in body weight gains were found between groups. Consistent results were found showing significantly higher packed cell volume (PCV) values in the T and S groups compared to NT and CAR groups. Overall, these results confirm a positive effect associated with the feeding of lambs with tanniniferous resources on host resilience (PCV values) and against gastrointestinal parasitic nematodes by affecting some biological traits of worm populations (e.g. eggs per gram of faeces and worm numbers). However, the anthelmintic effects differed between the two tannin-containing resources, which might be associated with the quantity and/or quality of secondary metabolites (condensed tannins and/or other polyphenols).

Highlights

Gastrointestinal parasitic nematodes (GINs) strongly affect livestock health, welfare and production in small ruminants because of the major economic losses, clinical signs and possible deaths which they provoke
The specific aims of the present study were: (1) to compare the antiparasitic activity of sainfoin hay and carob pods given as part of a concentrate meal under in vivo conditions in lambs which were experimentally trickle infected with two GIN species, (2) to confirm the benefits of these plants on host resilience by measuring certain production and pathophysiological parameters
Compared to the NT groups fed with lucerne (Medicago sativa), the results showed a reduction of À68% for the S group and of À19% for the CAR group on D42

Summary

Introduction

Gastrointestinal parasitic nematodes (GINs) strongly affect livestock health, welfare and production in small ruminants because of the major economic losses, clinical signs and possible deaths which they provoke. The societal demand to reduce chemicals in agriculture in order to avoid drug residues in animal products and the possible environmental consequences [21] are increasingly considered. There is a strong impetus for research on alternative approaches to AH drugs [14]. Among those options, evidence has accumulated over the last 20 years to suggest that some bioactive tannin-rich (TR) plants have anthelmintic effects [12, 19]. Several studies so far have supported the hypothesis that condensed tannins (CTs) [22, 23] and/or other flavonoids [3, 5] play a significant role in the AH effects of these forages when consumed by animals

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