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Worldwide, parasitic gastrointestinal nematodes continue to threaten animal health, welfare, and production in outdoor breeding systems of small ruminants. For more than 50 years, the control of these parasitic worms has relied on the use of commercial synthetic anthelmintics. However, anthelmintic resistance in worm populations is nowadays widespread and requires novel solutions. The use of tannin-rich plants has been suggested as an alternative to synthetic anthelmintics to control gastrointestinal nematodes. The majority of previous studies have focused on the activity of proanthocyanidins (syn condensed tannins), and less is known about ellagitannins. In this study, the effects of 30 structurally unique ellagitannins on the exsheathment of third-stage infective larvae were examined on Haemonchus contortusand Trichostrongylus colubriformisby the in vitro larval exsheathment inhibition assay. Ellagitannins were found to be promising natural anthelmintics as they showed direct inhibition on larval exsheathment for both nematode species. In general, ellagitannins were more efficient at inhibiting the exsheathment of H. contortuslarvae than those of T. colubriformis. The efficiency of inhibition increased as the degree of oligomerization or the molecular weight of the ellagitannin increased. Otherwise, we found no other structural features of ellagitannins that significantly affected the anthelmintic activity on the third-stage infective larvae. The effective concentrations were physiologically relevant and should be achievable in the gastrointestinal tract also in in vivo conditions.

Condensed tannins (CTs) account for up to 20% of the dry matter in forage legumes used as ruminant feeds. Beneficial animal responses to CTs have included improved growth, milk and wool production, fertility, and reduced methane emissions and ammonia volatilization from dung or urine. Most important is the ability of such forages to combat the effects of gastrointestinal parasitic nematodes. Inconsistent animal responses to CTs were initially attributed to concentration in the diet, but recent research has highlighted the importance of their molecular structures, as well as concentration, and also the composition of the diet containing the CTs. The importance of CT structural traits cannot be underestimated. Interdisciplinary research is the key to unraveling the relationships between CT traits and bioactivities and will enable future on‐farm exploitation of these natural plant compounds. Research is also needed to provide plant breeders with guidelines and screening tools to optimize CT traits, in both the forage and the whole diet. In addition, improvements are needed in the competitiveness and agronomic traits of CT‐containing legumes and our understanding of options for their inclusion in ruminant diets. Farmers need varieties that are competitive in mixed swards and have predictable bioactivities. This review covers recent results from multidisciplinary research on sainfoin (OnobrychisMill. spp.) and provides an overview of current developments with several other tanniniferous forages. Tannin chemistry is now being linked with agronomy, plant breeding, animal nutrition, and parasitology. The past decade has yielded considerable progress but also generated more questions—an enviable consequence of new knowledge!

Previous studies have illustrated that different bioactive legume fodders containing condensed tannins might represent one of the options for integrated sustainable control of gastrointestinal nematodes (GIN) in ruminants, which may help address the worldwide development of resistance to synthetic anthelmintics. More recently, impetus has been given to assess the potential antiparasitic activity of less conventional resources, represented by different agro-industrial by-products (AIBPs). This review presents in vitroand in vivoresults obtained with a range of tannin-containing AIBPs of various geographical and botanical origins, namely AIBP of nuts, temperate and tropical barks, carob, coffee and cocoa. They tend to confirm the “proof of concept” for their antiparasitic effects and also for other aspects of ruminant production in an agro-ecological context. Socio-economic aspects of the exploitation of such non-conventional resources are also discussed as potential models of the circular economy, by using waste. The different modes of use of these resources are presented in this review, as well as strengths, weaknesses, opportunities, and threats (SWOT) analyses to illustrate the advantages and limitations of on-farm use.

The recent increase in interactions between wildlife and domestic animals has heightened the risks of transmission of pathogens between wildlife, livestock, and humans. Our objective was to better understand how the spatial behavior of wildlife impacts their exposure to pathogens. We carried out a 5-year serological survey of Toxoplasma gondiiand Chlamydia abortusin a roe deer population (Capreolus capreolus) living in a rural landscape and monitored using GPS technology. We tested whether the apparent seroprevalence of these pathogens was related to the characteristics of roe deer’s home range, indirectly reflecting the probability of contact between deer and domestic hosts (cats for T. gondiiand ruminants for C. abortus). We controlled for the effects of temperature and rainfall, as local weather can affect pathogen survival in the environment. Overall, apparent seroprevalences were 43.7 and 15.8 % for T. gondii(N= 135) and C. abortus(N= 133), respectively. The apparent seroprevalence to T. gondiiincreased with the proportion of human dwellings (a proxy of cat presence) within the roe deer’s core home range and was higher during mild and wet years. This result illustrates how the spatial behavior of wild animals can modulate their exposure to pathogens through the degree of spatial overlap with a domestic host. By contrast, apparent seroprevalence to C. abortusincreased with the annual number of frosty days but not with the proportion of meadows occupied by domestic ruminants within the core home range. This suggests that the cycle of C. abortusin wild animals could be somewhat independent from that in livestock.

In 2007, the world goat population was estimated at 831 million, compared with 1.09 billion sheep, but the goat population is expanding more rapidly. More than 90% of goats are found in developing countries, with the primary commodity being its meat. The commonly used description of the goat as the “cow of the poorest” underlines its importance for small farmers. However, in the developed world (eg, the European Union and much of North America), the value of goats relates to its select ability to produce high yields of milk and the increased returns associated with the dairy products, particularly artisanal cheeses. Therefore, the current success of goats seems to be related to 2 characteristics: (1) its ability to efficiently convert low-quality forages into high-quality protein sources, that is, milk and meat, in developing countries and (2) its ability to produce commodities for valuable niche markets in developed countries. In both systems, parasitism with helminths, and particularly nematodes of the gastrointestinal tract is a major threat for health and production.

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.

- In an experiment lasting 4 years, changes in the Teladorsagia circumcincta and Trichostrongylus colubriformis populations were compared in lambs and adult sheep with differing resistance statuses. Two flocks of 30 rams (resistant R and susceptible S) grazed separate pastures and 8 rams were slaughtered in the middle and at the end of each grazing season. Five groups of tracer lambs were added each year to estimate the pasture infectivity and were killed for worm counts. The availability of animals with differing resistance statuses (rams and tracer lambs) and differing levels of infection made it possible to investigate the number, size and fecundity of worms of these two species. The inflammatory response was measured in the rams by counting the globule leukocytes, mast cells and eosinophils in the fundic, pyloric and intestinal mucosa. In the tracer lambs, the daily egg production by the female worms of both species was negatively correlated with the worm burden. Worm length accounted for 60 and 70% of the variation in the number of eggs in utero for T. circumcincta and T. colubriformis respectively. Worm length was closely associated with the resistance status of the host; there were greater differences between lambs, and S and R rams for T. colubriformis. T. circumcincta worm lengths were not affected by the worm number. Globule leukocyte counts were related to the worm burdens, and mast cell counts to worm length in the R and S rams. The number, size and fecundity of the worms may well be regulated by similar mechanisms in both species, but T. colubriformis seemed to be more intensively regulated than T. circumcincta. This finding could be useful in devising more effective methods of parasite control.

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.

Cellular and humoral local responses were investigated following repetitive artificial Oestrus ovis infections in lambs. The presence of larvae induced a huge local recruitment of either leucocytes (T and B lymphocytes, macrophages) or granulocytes (eosinophils, mast cells and globule leucocytes). This cellular response was more pronounced in the ethmoid and sinus (development sites of second and third instar larvae) than in the septum or turbinates where first instar larvae migrate. Infected lambs produced Oestrus ovis specific IgG and IgA antibodies in their mucus. This local humoral response was mainly directed against larval salivary gland antigens and not against larval digestive tract antigens. Compared to the control animals, the sinusal mucosa of infected animals was extremely thickened and the epithelium exhibited hyperplasia, metaplasia and eosinophilic exocytosis. The possible roles of these local immune responses in the regulation of O. ovis larvae populations in sheep are discussed.

Numerous studies have examined the interactions between protein nutrition and the response to nematode parasitism in sheep, but very few in goats. Compared with other ruminants, goats are less resistant to nematode infection. In addition, in dairy goats, high producing animals have been shown to be less resistant and less resilient to infection compared to low producing ones. The objective of the present study was to examine the consequences of protein supplementation on both resistance and resilience of dairy goats to nematode trickle infection, taking into account the initial level of milk production of the animals. During a 14-week period, 40 milking goats received a high protein (HP) diet supplying 130% of the protein requirements, and 38 goats were fed a intermediate protein (IP) diet (120% of the protein requirements). In addition, half of each group was given a weekly trickle infection with Trichostrongylus colubriformis larvae, the other part of the flock remained non-infected. Faecal egg counts (FEC), eosinophil counts and pathophysiological data (urea, albumin and inorganic phosphate concentrations in the serum) were measured twice a month. Milk production data (milk yield, protein and fat contents) were also recorded every 15 days. The results showed that FECs were lower (p $<$ 0.05) and eosinophil counts higher (p $<$ 0.05) in the animals receiving the HP diet suggesting that resistance was enhanced by protein supplementation. Meanwhile, milk parameters (related to resilience) were not affected by the level of protein in the diet when considering the whole groups. In contrast, in the high producing goats, the milk production and milk composition parameters were improved with the HP diet. To conclude, we have seen that the expression of both resistance and resilience did not appear when the coverage of the protein requirements was insufficient. Because the milk production is dependent on the protein supply, we suggest that there is a competition in the use of the protein between the development of resistance and the milk production.

This study assessed the ultrastructural changes caused in adult Haemonchus contortusobtained from goats fed fodder based on polyphenol-rich plants Lysiloma latisiliquumor Onobrychis viciifoliaor from goats drenched with quebracho extract, Schinopsisspp. The H. contortuswere obtained from artificially infected goats used as models to investigate the anthelmintic effect of feeding or drenching with the polyphenol-rich materials. Nematode populations were exposed to polyphenol-rich plant materials by feeding host goats for 8 consecutive days (D28 to D35 post-infection) with (a) L. latisiliquumfodder at 800 g fresh basis/day, (b) O. viciifoliafodder offered ad libitum, and (c) drenched with a solution containing quebracho extract (90 g/day). Meanwhile, control H. contortuswere obtained from goats fed polyphenol-free diets. The H. contortusspecimens were recovered from the goats on D36 post-infection, and transmission electron microscopy (TEM) was used to identify ultrastructural changes. In vivoexposure to different polyphenol-rich plant materials caused vacuolization of the nematodes’ intestinal, muscular and hypodermal cells. These alterations represent the first evidence of cell damage caused in H. contortuswhen hosts were fed or drenched with polyphenol-rich materials. Ultrastructural changes affecting several types of cells could explain modifications in worm motility and nutrition, eventually affecting H. contortusreproductive success. This study contributes to our understanding of the mechanisms of action of polyphenol-rich plants against H. contortuswhen given as nutraceuticals to goats.

Species identification of trichostrongyle nematodes by PCR-linked RFLP. International Journal for Parasitology24: 291–293. Restriction fragment length polymorphisms (RFLP) of the second internal transcribed spacer (ITS-2) of ribosomal DNA were examined for 6 species of ruminant nematodes; Trichostrongylus colubriformis, T. axei, T. vitrinus, Haemonchus contortus, Teladorsagia circumcinctaand Cooperia oncophora. The ITS-2 of each species was amplified by PCR and restricted with the endonucleases DraI, HinfI, RsaI and VspI. Using this approach, the 6 species could be distinguished. No intraspecific variation in RFLP's has been detected so far in the ITS-2 of these species, suggesting that this technique has considerable potential for the identification of eggs of different nematode species in faecal samples.

Gastrointestinal nematodes are a major threat to small ruminant rearing in the Sahel area, where farmers traditionally use bioactive plants to control these worms, including Acacia niloticaand Acacia raddiana. The main aim of this study was to screen the potential anthelmintic properties of aqueous and acetone extracts of leaves of these two plants based on three in vitroassays: (1) the egg hatch inhibition assay (EHA); (2) the larvae exsheathment inhibition assay (LEIA) using Haemonchus contortusas a model; and (3) an adult mortality test (AMT) applied on Caenorhabditis elegans. For the EHA, only A. raddianawas effective with IC50= 1.58 mg/mL for aqueous extract, and IC50= 0.58 mg/mL for acetonic extract. For the LEIA, all extracts inhibited the exsheathment of larvae compared to the controls, and the aqueous extract of A. niloticawas more larvicidal with IC50= 0.195 mg/mL. In general, all responses to the substances were dose-dependent and were significantly different from the control group (p< 0.05). For the AMT, the extracts of the two Acaciaspecies were effective but A. raddianashowed greater efficacy with 100% mortality at 2.5 mg/mL and LC50= 0.84 mg/mL (acetonic extract). The addition of polyvinyl polypyrrolidone (PVPP) to the extracts suggested that tannins were responsible for blocking egg eclosion and inducing adult mortality but were not responsible for exsheathment inhibition. These results suggest that the leaves of these Acaciaspecies possess ovicidal and larvicidal activities in vitroagainst H. contortus, and adulticidal effects against C. elegans.