Hedges and Woody Strips Browsing by Cattle on Pasture in Wallonia, Belgium

Shrub and tree forages are commonly used in animal production in many regions of the world. Nonetheless, in Western Europe, and especially in Wallonia in Belgium, hedges and woody strips have disappeared from the agricultural landscape over the past 60 years. Browse species are usually rich in plant secondary compounds such as tannins whose benefits on CH4 production and intestinal parasitism have been highlighted (Ramírez-Restrepo et al. 2010). Currently, agri-environmental measures taken by the Walloon government promote hedges and woody strips in pastures, raising the interest in browse species functionalities in ruminant production. This study aimed at: (1) determining the influence of the access to a hedge on the behaviour of cattle on pasture; and (2) evaluating the fermentability by rumen microbes of foliage of woody species promoted in the Walloon landscape

Intra‐cultivar potential of Desmanthus spp. as a greenhouse gas mitigation strategy for tropical livestock pastoral systems

Improved agricultural efficiency and reduction in the impacts of tropical livestock farming on habitat degradation require global approaches that enhance ruminant farming functionality in terms of feed use efficiency, emissions and food security. This study evaluated the in vitro mitigation potential of the prostrate to erect, herbaceous Desmanthus spp. pasture legume adapted to semiarid clay soil land types in northern Australia. D. bicornutus, D. leptophyllus and D.virgatus were seasonally harvested from commercial plots by Agrimix Pty. Ltd. Samples of the legumes and the control Rhodes grass (Chloris gayana) using ruminal fluid from grazing Brahman (Bos indicus) steers were incubated in vitro (Ankom RF1 Technology) for 24, 48 and 72 h. Overall, the in vitro organic matter degradability (OMD) and methane production between Desmanthus species differed (P < 0.001). Compared to the control (0.656 ± 0.027 proportion of total OM) at 48 h of incubation, D. leptophyllus showed lower OMD (0.479 ± 0.016), while D. bicornutus (0.688 ± 0.016) and D. virgatus (0.619 ± 0.015) were different from each other, but similar to the control. Methane production (ml/g OM) was 15.7 ± 1.54, 3.7 ± 0.89, 12.0 ± 0.95 and 11.7 ± 0.95, respectively. It is suggested that the impact of these attributes may benefit household farmers in developing economies to expand productivity, improve livelihoods and meet the growing food consumption. Further analyses of the intra‐cultivar characteristics of Desmanthus spp. will complement the design of sustainable and efficient interventions across tropical pastoral feeding systems, with a particular emphasis on large‐scale grazing operations

Oncolytic adenovirus drives specific immune response generated by a poly-epitope pDNA vaccine encoding melanoma neoantigens into the tumor site

Abstract Background DNA vaccines against cancer held great promises due to the generation of a specific and long-lasting immune response. However, when used as a single therapy, they are not able to drive the generated immune response into the tumor, because of the immunosuppressive microenvironment, thus limiting their use in humans. To enhance DNA vaccine efficacy, we combined a new poly-epitope DNA vaccine encoding melanoma tumor associated antigens and B16F1-specific neoantigens with an oncolytic virus administered intratumorally. Methods Genomic analysis were performed to find specific mutations in B16F1 melanoma cells. The antigen gene sequences were designed according to these mutations prior to the insertion in the plasmid vector. Mice were injected with B16F1 tumor cells (n = 7–9) and therapeutically vaccinated 2, 9 and 16 days after the tumor injection. The virus was administered intratumorally at day 10, 12 and 14. Immune cell infiltration analysis and cytokine production were performed by flow cytometry, PCR and ELISPOT in the tumor site and in the spleen of animals, 17 days after the tumor injection. Results The combination of DNA vaccine and oncolytic virus significantly increased the immune activity into the tumor. In particular, the local intratumoral viral therapy increased the NK infiltration, thus increasing the production of different cytokines, chemokines and enzymes involved in the adaptive immune system recruitment and cytotoxic activity. On the other side, the DNA vaccine generated antigen-specific T cells in the spleen, which migrated into the tumor when recalled by the local viral therapy. The complementarity between these strategies explains the dramatic tumor regression observed only in the combination group compared to all the other control groups. Conclusions This study explores the immunological mechanism of the combination between an oncolytic adenovirus and a DNA vaccine against melanoma. It demonstrates that the use of a rational combination therapy involving DNA vaccination could overcome its poor immunogenicity. In this way, it will be possible to exploit the great potential of DNA vaccination, thus allowing a larger use in the clinic

Oncolytic adenovirus drives specific immune response generated by a poly-epitope pDNA vaccine encoding melanoma neoantigens into the tumor site

Background: DNA vaccines against cancer held great promises due to the generation of a specific and long lasting immune response. However, when used as a single therapy, they are not able to drive the generated immune response into the tumor, because of the immunosuppressive microenvironment, thus limiting their use in humans. To enhance DNA vaccine efficacy, we combined a new poly-epitope DNA vaccine encoding melanoma tumor associated antigens and B16F1-specific neoantigens with an oncolytic virus administered intratumorally. Methods: Genomic analysis were performed to find specific mutations in B16F1 melanoma cells. The antigen gene sequences were designed according to these mutations prior to the insertion in the plasmid vector. Mice were injected with B16F1 tumor cells (n = 7-9) and therapeutically vaccinated 2, 9 and 16 days after the tumor injection. The virus was administered intratumorally at day 10, 12 and 14. Immune cell infiltration analysis and cytokine production were performed by flow cytometry, PCR and ELISPOT in the tumor site and in the spleen of animals, 17 days after the tumor injection. Results: The combination of DNA vaccine and oncolytic virus significantly increased the immune activity into the tumor. In particular, the local intratumoral viral therapy increased the NK infiltration, thus increasing the production of different cytokines, chemokines and enzymes involved in the adaptive immune system recruitment and cytotoxic activity. On the other side, the DNA vaccine generated antigen-specific T cells in the spleen, which migrated into the tumor when recalled by the local viral therapy. The complementarity between these strategies explains the dramatic tumor regression observed only in the combination group compared to all the other control groups. Conclusions: This study explores the immunological mechanism of the combination between an oncolytic adenovirus and a DNA vaccine against melanoma. It demonstrates that the use of a rational combination therapy involving DNA vaccination could overcome its poor immunogenicity. In this way, it will be possible to exploit the great potential of DNA vaccination, thus allowing a larger use in the clinic.Peer reviewe

IFN-Lambda (IFN-λ) Is Expressed in a Tissue-Dependent Fashion and Primarily Acts on Epithelial Cells In Vivo

Interferons (IFN) exert antiviral, immunomodulatory and cytostatic activities. IFN-α/β (type I IFN) and IFN-λ (type III IFN) bind distinct receptors, but regulate similar sets of genes and exhibit strikingly similar biological activities. We analyzed to what extent the IFN-α/β and IFN-λ systems overlap in vivo in terms of expression and response. We observed a certain degree of tissue specificity in the production of IFN-λ. In the brain, IFN-α/β was readily produced after infection with various RNA viruses, whereas expression of IFN-λ was low in this organ. In the liver, virus infection induced the expression of both IFN-α/β and IFN-λ genes. Plasmid electrotransfer-mediated in vivo expression of individual IFN genes allowed the tissue and cell specificities of the responses to systemic IFN-α/β and IFN-λ to be compared. The response to IFN-λ correlated with expression of the α subunit of the IFN-λ receptor (IL-28Rα). The IFN-λ response was prominent in the stomach, intestine and lungs, but very low in the central nervous system and spleen. At the cellular level, the response to IFN-λ in kidney and brain was restricted to epithelial cells. In contrast, the response to IFN-α/β was observed in various cell types in these organs, and was most prominent in endothelial cells. Thus, the IFN-λ system probably evolved to specifically protect epithelia. IFN-λ might contribute to the prevention of viral invasion through skin and mucosal surfaces

Les arbres et arbustes influencent le comportement de bovins au pâturage et les fermentations ruminales

Hedgerows and woody strips have been used to enclose fields but declined due to the loss of a direct economic value, abandonment of traditional management techniques and agricultural intensification. Nowadays, shrubs and trees on pastures are promoted again through environment-friendly policies and the interest in using them as forage for ruminant increases in both temperate and tropical ecosystems. Woody plants on farmland could yield a wide range of ecosystem services and provide benefits for farmers and their animals such as forage supply to livestock, animal protection against severe weather and reduced parasitic infestation. Moreover, shifts in digestive physiology can be observed that will in turn affect the welfare and the performances of the animal and the production system as a whole. Therefore, in order to contribute to the development of sustainable systems using shrubs and trees as a feed component in its full right, the aim of this work was to investigate the influence of trees and shrubs on the behaviour of grazing cattle and their selectivity towards woody species, and to determine the changes induced by temperate and tropical shrub and tree species on rumen fermentation. Firstly, the behaviour of grazing dairy heifers was recorded during the whole grazing season as well as their selectivity towards temperate woody species in a hedge. It was concluded that having access to a hedge influenced the behaviour of grazing cattle, as the animals ingested woody plants in each season but mostly when the available pasture biomass was lower. The most selected species were Carpinus betulus, Corylus avellana, Cornus sanguinea and Crataegus monogyna. Secondly, the chemical composition, in vitro rumen fermentation profile and protein precipitation capacity (PPC) of the temperate shrub and tree species were measured. The analyses showed that Fraxinus excelsior presented the most interesting profile in terms of chemical composition and in vitro fermentation production. Among the preferred species, C. monogyna and C. avellana produced lower CH4 and the latest had the highest PPC. Thirdly, three newly-developed cultivars of the tropical Desmanthus genus were studied for their effects on in vitro rumen fermentation including potential to reduce CH4. Desmanthus leptophyllus and D. bicornutus had the highest anti-methanogenic potential, and D. bicornutus was more digestible. In conclusion, both temperate and tropical shrub and tree fodder are promising to supplement cattle with good quality forage. Cattle can browse woody species voluntarily, however, further investigations are needed to provide relevant practical recommendations on how to manage this resource adequately in order to balance intake by the animal and regrowth capacity of the plant. The impact of management strategies relying on cutting and preservation should also be assessed. Moreover, benefits of shrubs and trees on pastures beyond the animal feeding and nutrition are still poorly characterized while, in an agroecological perspective, they can contribute to a significant improvement of the sustainability of ruminant production systems.Les haies et bandes boisées ont toujours été utilisées pour délimiter les prairies mais ont peu à peu disparu du paysage agricole en raison des pertes économiques qu’elles engendrent, de l’abandon des modes de gestion traditionnels et de l’intensification agricole. A présent, l’implantation d’arbres et arbustes est à nouveau encouragée suite à la mise en place de mesures respectueuses de l’environnement, et l’intérêt de leur utilisation comme fourrage pour les ruminants est croissant aussi bien dans les écosystèmes tempérés que tropicaux. Au sein des systèmes de productions, les plantes ligneuses peuvent rendre de nombreux services écosystémiques et procurer des bénéfices pour les agriculteurs et leurs animaux tels que l’apport de fourrages, la protection contre le mauvais temps et une réduction de l’infestation parasitaire. De plus, lorsqu’ils sont ingérés, ces fourrages peuvent entraîner des changements de la physiologie digestive qui à leur tour, vont influencer le bien-être et les performances des animaux ainsi que le système de production dans son ensemble. Dès lors, afin de contribuer au développement de systèmes durables utilisant les arbres et arbustes comme composante fourragère, le but de ce travail a été d’évaluer l’influence de plantes ligneuses sur le comportement de bovins au pâturage, de déterminer leur sélectivité vis-a-vis de ces espèces ligneuses, ainsi que de mesurer les changements induits par des espèces tempérées et tropicales d’arbres et arbustes sur la fermentation ruminale. Premièrement, le comportement de génisses laitières au pâturage a été observé pendant toute la saison de pâturage ainsi que leur sélectivité vis-à-vis des espèces ligneuses présentes dans une haie. Il a été conclu que l’accès à une haie a influencé le comportement des bovins au pâturage, puisque les animaux ont brouté des plantes ligneuses à chaque saison. Cela a été principalement observé lorsque la biomasse disponible de la prairie était faible. Les espèces les plus sélectionnées étaient Carpinus betulus, Corylus avellana, Cornus sanguinea et Crataegus monogyna. Deuxièmement, la composition chimique, le profil de fermentation ruminale in vitro et la capacité à précipiter les protéines (CPP) des espèces d’abres et arbustes tempérés ont été mesurés. Les analyses ont montré que Fraxinus excelsior présentait le profil le plus intéressant en termes de composition chimique et de fermentation. Parmi les espèces les plus sélectionnées, C. monogyna et C. avellana ont produit moins de CH4 et cette dernière espèce a montré la CPP la plus élevée. Troisièmement, trois cultivars du genre tropical Desmanthus ont été étudiés pour leurs effets sur les fermentations ruminales in vitro ainsi que leur potentiel à réduire la production de CH4. Desmanthus leptophyllus et D. bicornutus ont présenté le meilleur potentiel anti-méthanogène, et D. bicornutus a présenté une plus grande digestibilité. En conclusion, les fourrages d’arbres et d’arbustes aussi bien tempérés que tropicaux sont prometteurs pour complémenter les bovins avec des plantes de bonne qualité. Les animaux peuvent brouter les espèces ligneuses volontairement, mais des investigations supplémentaires sont nécessaires pour fournir des recommandations pratiques pertinentes sur la gestion adéquate de cette ressource de manière à déterminer le meilleur équilibre entre l’ingestion par l’animal et la capacité de la plante à repousser. L’impact des stratégies de gestion basées sur la coupe et la conservation des fourrages ligneux devrait également être évalué. De plus, à côté de la nutrition animale, les bénéfices qu’apportent les arbres et arbustes en prairie sont encore peu caractérisés, alors que, d’un point de vue agro-écologique, ils pourraient contribuer à une amélioration significative de la durabilité des systèmes de production de ruminants

Interest of hedges and woody strips browsing for cattle on pasture in Wallonia

The establishment of agri-environmental measures in Wallonia promotes hedges and woody strips planting in the agricultural landscape. This study aimed at evaluating the influence of trees and shrubs access on the feeding behaviour of grazing heifers and determining the feeding value of woody species. The second objective was to assess the anti-parasitical effect of these ligneous forages. For 4 consecutive weeks from April to May 2012, 12 dairy heifers were equally distributed among two different groups: one with an open access to a woody hedge (experimental group) and the other not (control group). The feeding behavior of heifers was recorded during days of 10 hours, in relation to the available herbaceous biomass. At the end of the experiment, a faeces analysis was used to assess the presence and the number of parasites infesting heifers. The leaves of 12 woody species harvested in late May 2012 were analyzed for their chemical composition and their in vitro ruminal fermentability using a gas test. The results were compared to those obtained for white clover and ryegrass. The feeding behavior of heifers was influenced by their access to woody species. Indeed, grazing time of control animals (59.8%) was superior to animals that could browse the hedge (54.8%). The experimental animals browsed the ligneous when the pasture herbaceous biomass was the lowest (0.22 kg DM/kgBW*ha), namely the second week of the experiment only. During this week, browsing time represented 3.72% of the time spent on pasture. Faeces parasites analysis showed a significantly lower infestation of trichostrongyles in experimental animals. The chemical composition and kinetic parameters of in vitro ruminal fermentation varied significantly among woody species. The CP content ranged from 14.3% in Viburnum opulus to 31.9% in Sambucus nigra. Fraxinus excelsior had a CP content of 24.5% and a maximum gas production of 120ml/gDM. These values were similar to the values obtained for ryegrass (26.4% CP and 132.2 ml /gDM). The highest maximum gas volume produced was reached for Populus nigra (135.5 ml /gDM) and was equivalent to ryegrass. In conclusion, in the grazing conditions in Wallonia, browsing can be considered as complementary feeding for cattle on pasture with hedges. Indeed, some woody species appear promising for livestock nutrition such as Sambucus nigra, Fraxinus excelsior or Populus nigra. This work is a preliminary study in the sylvopastoral area. Future studies should be explored to confirm the results obtained in this study and to deepen knowledge of this area.La mise en place de mesures agro-environnementales en Région Wallonne favorise l’implantation de haies et bandes boisées dans les paysages agricoles. Le premier but de cette étude a été d’évaluer l’influence de l’accès à des arbres et arbustes sur le comportement alimentaire de génisses laitières au pâturage ainsi que de déterminer la valeur alimentaire potentielle du feuillage d’espèces ligneuses en alimentation animale. Le second objectif a été de déterminer l’effet anti-parasitaire de ces fourrages ligneux. Durant 4 semaines consécutives d’avril à mai 2012, 12 génisses laitières ont été réparties équitablement en deux groupes : l’un ayant accès à une haie de ligneux feuillus (groupe expérimental) et l’autre pas (groupe témoin). Le comportement alimentaire des génisses a été enregistré au cours de journées de pâturage de 10 heures, en lien avec la biomasse herbacée disponible. A la fin de l’essai, un examen des matières fécales a permis d’évaluer la présence et le nombre de parasites infestant les génisses. Les feuilles de 12 espèces ligneuses récoltées fin mai 2012 ont été analysées pour leur composition chimique et leur fermentescibilité ruminale in vitro à l’aide d’un gaz test. Les résultats ont été comparés à ceux obtenus pour le trèfle blanc et le ray-grass anglais. Le comportement alimentaire des génisses a été influencé par leur accès aux espèces ligneuses. En effet, le temps de pâturage des animaux témoins (59,8%) était supérieur aux animaux pouvant brouter à la haie (54,8%). Les animaux expérimentaux ont brouté les ligneux lorsque la biomasse herbacée de la prairie était la plus faible (0,22kgMS/kgPV*ha), à savoir la deuxième semaine de l’essai uniquement. Durant cette semaine, le temps consacré au broutage a représenté 3,72% du temps passé en prairie. L’analyse des parasites dans les matières fécales a démontré une infestation significativement moindre en trichostrongles pour les animaux expérimentaux. La composition chimique ainsi que les paramètres cinétiques de fermentation ruminale in vitro différaient entre les espèces ligneuses. La teneur en MAT a varié de 14,3% pour Viburnum opulus à 31,9% pour Sambucus nigra. Fraxinus excelsior a présenté une teneur en MAT de 24,5% et une production de gaz maximale de 120ml/gMS, valeurs proches du raygrass anglais (26,4%MAT et 132,2ml/gMS). Le volume maximal de gaz produit le plus élevé a été atteint par Populus nigra (135,5ml/gMS), équivalent au ray-grass anglais. En conclusion, dans les conditions de pâturages connus en Wallonie, le broutage peut être envisagé comme complément pour les bovins en prairies bordées de haies. En effet, certaines espèces ligneuses apparaissent prometteuses pour les productions animales telles que Sambucus nigra, Fraxinus excelsior et Populus nigra .Ce travail constitue une étude préliminaire dans ce domaine sylvopastoral. Des études futures sont à envisager afin de confirmer les résultats obtenus dans cette étude et d’approfondir les connaissances de ce domaine

Compatibility of using TiO2 and the faecal near-infrared reflectance spectrometry for estimation of cattle intake

peer reviewedCombining titanium dioxide (TiO2) as indigestible marker to faecal near-infrared reflectance spectrometry (F-NIRS) can be used to determine cattle feed intake and quality of ingested forage if F-NIRS spectra are not modified by the marker. This study aimed at determining the compatibility of TiO2 with F-NIRS. Three dry cows were fed a standard hay-based diet for three weeks supplemented with a daily dose of 0.1 % (10g) TiO2 during the last two weeks of the experiment. Faeces samples were collected every day and analysed for TiO2 and F-NIRS. Results suggest that TiO2 did not interfere with F-NIRS analyses. The calculations of crude protein, NDF, ADL contents, as well as dry matter intake did not change over time with increasing TiO2 in the faeces (P > 0.05). Slight differences observed for other predicted parameters seemed to be independent from TiO2. The higher Mahalanobis distance (H) for chemical composition (H = 7.2) independent from TiO2 inclusion could indicate that faecal spectra did not correspond exactly to the prediction database. Although 0.1% incorporation of TiO2 seem not to interfere with F-NIRS measurements, caution must be taken with higher levels of TiO2 as nothing indicates that interference could not appear

Is the behaviour of grazing cattle influenced by the presence of a hedge in the pasture?

The interest in using shrubs and trees as forage for cattle is raising in temperate regions, along with the environmental measures promoting hedges along pasture. This study aimed at determining the influence of the presence of a woody hedge on grazing cattle behavior as well as the evolution of this behavior during the grazing season. Twelve heifers were set to graze a standard ryegrass and clover meadow during the grazing season of 2013. The animals were divided in 2 groups : one with a free access to a hedge composed by 10 temperate shrub and tree species, the other with no access to a hedge (control). Their behavior (grazing, browsing and other activities) was monitored during 14h d-1 replicated 3d week-1 during 3 periods (May, July and September). Results suggest that both season and presence of a hedge have an influence on the behavior of heifers. Grazing, resting and rumination varied between the two groups in each period (P<0.05). The time spent browsing was influenced by the season (P<0.001); the heifers with an access to the hedge could browse 19.3% of the total time in May against 5.9 and 5.4% in July and September. Both control and experimental heifers grazed more with the progressing season, but the animals without the hedge grazed always more than the heifers that could graze and browse (49.6 vs 43.0%). In conclusion, browsing woody species represents a significant part of the time spent for forage ingestion, and variation in this behavior over the whole grazing season requires to investigate the influence of both pasture and browse availability and composition

Agroforestry for ruminants: a review of trees and shrubs as fodder in silvopastoral temperate and tropical production systems

Among the oldest agroforestry systems, silvopastoralism uses shrubs and trees to feed ruminants. The practice is common in extensive livestock production systems, while the intensification of grass-based systems in the past century has led to the removal of woody species from agricultural temperate landscapes. In Europe however, woody species are promoted again on grasslands through environment-friendly policies due to the ecosystem services they provide such as carbon sequestration, control of soil erosion, limitation of air-borne pollutants and biodiversity conservation. Positive effects of browse on rumen digestion and parasite control have also been documented across different plant species and regions. Under optimal conditions, feeding ruminants from woody fodder sustains animal production. Nonetheless, limitations can restrict the use of woody forage into animal diets, such as the presence of anti-nutritive and toxic compounds. The incorporation of this resource in ruminant feeding systems raises the question of the management of the interface between the plant and the animal. Various management systems are practiced. Temperate species such as Salix spp. and Populus spp. are fed to sheep and cattle in fodder blocks or by pruning trees in New Zealand, and Fraxinus spp. or Corylus avellana in hedgerows supply forage to livestock in Belgium, while Leucaena leucocepahala and Desmanthus spp. browsing is common in Australia. Nowadays, ensiling and pelleting techniques are being developed as a way to store browse forage. As the renewed interest in using shrubs and trees to feed ruminants is recent, especially in temperate regions, additional research about introducing optimally this resource within systems is needed.PhD grant of Sophie Vandermeule