Hervé Hoste

Climate change intensifies water scarcity and soil salinization, threatening agriculture and livestock systems, especially in arid Mediterranean regions. Halophytes and salt-tolerant plants offer sustainable alternatives to support ruminant health and productivity where traditional crops fail, helping mitigate climate impacts. This work evaluated seasonality effects on the biochemical properties, including proximate composition, minerals, antioxidant properties, and the phenolic composition of the aerial organs of halophytes and salt-tolerant species, aiming at their future exploitation in ruminant production as novel nutraceutical or phytotherapeutic products. Target species included four halophytic species according to the eHaloph database (Calystegia soldanella (L.) R. Br. 1810, Medicago marina L. 1753, Plantago coronopus L. 1753, and Limoniastrum monopetalum (L.) Boiss. 1848) and five salt-tolerant plants (Pistacia lentiscus L. 1753, Cladium mariscus (L.) Pohl 1809, Inula crithmoides L. (syn. Limbarda crithmoides Dumort. 1827), Helichrysum italicum subsp. picardii (Boiss. & Reut.) Franco 1984, and Crucianella maritima L. 1753). H. italicum, M. marina, and C. soldanella appear well-suited for nutraceutical applications, while P. lentiscus, L. monopetalum, and C. mariscus hold promise for the development of, for example, phytotherapeutic products. This research underscores the significance of seasonal and species-specific variations in nutrient and phytochemical composition, displaying a range of opportunities for novel, sustainable, and tailored solutions to ruminant production systems in arid environments.

The effects of a high dietary (26%) incorporation of dehydrated sainfoin (DS) (Perly cultivar) on the performance and health of reproductive does and growing rabbits were analysed in a sub-optimal professional breeding environment (presenting previous coccidiosis), and over two non-consecutive reproductive cycles (2 replicates). Performance and health of does and growing rabbits were compared for 2 groups of 194 does and associated litters, when fed isonutritive feeds containing either 0 or 26% DS (DS0 and DS26 groups). Dietary DS incorporation had no effect on doe live weight, fertility rate, mortality, culling rate and doe coccidia excretion levels (P>0.05). In replicate 1, kit growth before weaning was similar among the two groups, but was 12% lower for the DS26 group in the 2nd replicate (significant interaction). Similarly, a significant interaction was detected between the effect of the diet and the replicate for the mortality rate of kits before weaning, i.e. a higher mortality was detected for DS26 (3.3 vs. 1.8%) in replicate 1, while in replicate 2 it was lower (2.1 vs. 4.4%). After weaning, the post-weaning growth rate was improved by 4% (P=0.02) for the DS26 group, while the mortality rate decreased (7.1 vs. 4.5%, P<0.001). Coccidia excretions of growing rabbits were not affected by dietary sainfoin or by replicates. A high incorporation of DS (26%) should be recommended after weaning to improve the performance of growing rabbits without impact on reproducing does.

Les parasites (Helminthes, Protozoaires, Acariens, Insectes) restent responsables de pathologie majeures impactant l’élevage des ruminants. Pendant des décennies, la maitrise de ces divers groupes de parasites a reposé pour l’essentiel sur des molécules de synthèse développées par l’industrie pharmaceutique. Cependant, cette gestion quasi exclusive par des traitements chimiques se trouve désormais confrontée à plusieurs limites : d’une part, une demande sociétale croissante pour réduire les intrants chimiques en élevage dans le cadre d’une agriculture évoluant vers des critères agroécologiques ; d’autre part, le phénomène général de résistances aux antiparasitaires dans les différents groupes mentionnés. Dans ce contexte, le concept de gestion intégrée du parasitisme fondée sur une combinaison de solutions alternatives aux molécules de synthèse devient le nouveau paradigme de lutte applicable aux divers groupes de pathogènes. L’objectif de cette revue est de présenter quelques exemples de solutions complémentaires aux substances de synthèse en se fondant sur deux modèles principaux : les nématodes gastro intestinaux et les insectes chez des petits ruminants ou les bovins.

This study developed and evaluated an in vitro rumen incubation (IVRI) method to describe the exsheathment kinetics of Haemonchus contortus third-stage infective larvae (L₃) in ruminal liquor (RL). The specific objectives were (i) to standardize the IVRI method to facilitate the contact between L₃ and RL as well as the larval recovery, and (ii) to apply the IVRI method to describe the exsheathment kinetics of H. contortus and to select the best fitting nonlinear model. Incubation devices containing H. contortus larvae were incubated according to the IVRI technique in cattle RL or PBS. The incubation conditions included RL mixed with a nitrogen-rich media, maintained at 39 °C, with pH = 7.0, vented with CO₂ and manual agitation. The larvae were recovered after 0, 1, 3, 6, 9, 12, and 24 h. The exsheathed and ensheathed larvae were counted to estimate the exsheathment (%) in RL or PBS. Exsheathment in RL was analyzed with nonlinear regression models: Exponential, Gompertz, Logistic, Log-Logistic, and Weibull. The models’ fit was compared to select the one that best described the exsheathment kinetics. The exsheathment in RL reached 6.52%, 20.65%, 58.22%, 69.24%, 73.08%, and 77.20% in 1, 3, 6, 9, 12, and 24 h, respectively. Although the Gompertz, Weibull, and Logistic models were adequate to describe the observed exsheathment, the Log-Logistic model had the best fit. The IVRI method using bovine RL represents a suitable tool for the study of the in vitro exsheathment kinetics of H. contortus L₃.

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 presentsin vitroandin 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.

Purpose Some agroindustrial by-products could be used as nutraceutical materials for small ruminants helping with their nutrition while controlling their gastrointestinal nematodes. This study evaluated the potential in vitro nutraceutical value of pod husks and leaves of three varieties of Theobroma cacao using two Haemonchus contortus isolates with different polyphenol susceptibility. Methods Leaves and husks from three T. cacao varieties (AZT, CAL and CEY) were evaluated for their bromatological composition, in vitro dry matter digestibility and polyphenol content. Acetone:water extracts (70:30) of each plant variety were evaluated using the egg hatch and larval exsheathment inhibition tests, using two isolates (FESC and PARAISO) of H. contortus. Effective concentrations 50% (EC₅₀) were determined for both tests. The role of polyphenols was confirmed using polyvinylpolypyrrolidone. L₃ exposed to CAL leaf extract were submitted to transmission electron microscopy. Results Both plant materials showed a good nutritional value to complement protein-rich diets for small ruminants. Extracts inhibited exsheathment of H. contortus L₃ more effectively than the egg hatching, and the leaf extracts were more active than husk extracts in the L₃ exsheathment inhibition. The FESC isolate was more sensitive to extracts. Polyphenols blocked exsheathment inhibition of leaf extracts. Structural damage was observed in the sheath and muscles of L₃ exposed to CAL leaf extracts. Conclusion The two T. cacao materials tested showed their potential to be used as ruminant feeds. Extracts affected H. contortus by blocking L₃ exsheathment, particularly with the leaf extracts. The in vivo nutraceutical value should be confirmed in small ruminants.

This study assessed the ultrastructural changes caused in adult Haemonchus contortus obtained from goats fed fodder based on polyphenol-rich plants Lysiloma latisiliquum or Onobrychis viciifolia or from goats drenched with quebracho extract, Schinopsis spp. The H. contortus were 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. latisiliquum fodder at 800 g fresh basis/day, (b) O. viciifolia fodder offered ad libitum, and (c) drenched with a solution containing quebracho extract (90 g/day). Meanwhile, control H. contortus were obtained from goats fed polyphenol-free diets. The H. contortus specimens were recovered from the goats on D36 post-infection, and transmission electron microscopy (TEM) was used to identify ultrastructural changes. In vivo exposure 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. contortus when 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. contortus reproductive success. This study contributes to our understanding of the mechanisms of action of polyphenol-rich plants against H. contortus when given as nutraceuticals to goats.

Chez les ruminants élevés au pâturage, les strongles gastro-intestinaux (SGI) peuvent induire des pertes de production, voire des atteintes cliniques chez les animaux non immuns. Le contrôle de l’infestation repose essentiellement sur les traitements anthelminthiques (AH) administrés fréquemment sans évaluation préalable de la réalité du risque parasitaire. Cette synthèse vise tout d’abord à exposer les principaux risques associés à ce recours insuffisamment raisonné aux AH : apparition de populations de parasites résistants aux AH, écotoxicité pour la microfaune prairiale dégradant les fèces, et installation retardée de l’immunité anti-strongles (notamment chez les bovins). Les stratégies de traitement ciblé-sélectif devraient permettre de maîtriser ces risques tout en prévenant les atteintes cliniques et sécurisant les performances des animaux. Il s’agit de rationaliser les traitements AH en ciblant les troupeaux ou les lots et les périodes à risque, et en sélectionnant les individus les plus parasités ou « souffrant » le plus du parasitisme. Cette synthèse vise donc ensuite à décrire les outils et les indicateurs étudiés pour mettre en œuvre de telles stratégies chez les ruminants. Il s’agit d’indicateurs zootechniques (gain moyen quotidien, parité, niveau de production…), cliniques (FAMACHA©, index de diarrhée…), parasitologiques (coproscopie, niveau d’anticorps anti-SGI…), ou d’indicateurs de conduite (modalité de pâturage), et aussi d’outils informatiques (modélisation du recyclage parasitaire). Leur fiabilité et leur opérationnalité sont variables. La mise en place de telles stratégies nécessitera de dépasser les freins à l’acceptation de ces nouvelles pratiques tant au niveau des éleveurs que des vétérinaires prescripteurs. Cet usage raisonné des AH assurerait une meilleure durabilité du contrôle de l’infestation par les SGI.

Acacia nilotica var adansonii (Guill. et Perr.) O. Ktze and Acacia raddiana (Savi) species are local ressources important to feed animals in Sahelian area of Burkina Faso. Thus, this experiment was to investigate the in vitro effect of both Acacias on ruminal fermentation, CH4 production and rumen microbial community using a semi-automatic system. In all experiments, 25 mL of the inoculum solution was incubated with 50 mL of buffered rumen fluid at 39 °C and gas production was measured at 2, 4, 8, 12 and 24 h. The results show that A. nilotica was rich in condensed tannins and fiber content compared to A. raddiana which was rich in total tannins. A. raddiana treatment presented greater degradability of organic matter and lower CH4 production compared to A. nilotica and control group (P0.05). We conclude that A. nilotica leaves showed negative effect on ruminal fermentation due to high fiber and CT content, and A. raddiana could be an interesting plant to increase fiber digestion and reduce CH4 production in vitro.