Elevated CO\u3csub\u3e2\u3c/sub\u3e and Extreme Climatic Events Modify Nitrogen Content and Ruminal Protein Digestion of Temperate Grassland

This study was aimed at analyzing changes in nitrogen (N) content and in vitro protein rumen digestion of an upland grassland exposed to climate changes in controlled conditions. Monoliths of grassland were inserted in 12 macrocosms in which climatic conditions for the 2050s were simulated (i.e., +2.3°C and 33 mm less precipitation compared to the current climatic conditions). Six of them were subjected to ambient CO2 (390 ppm) while the other six were subjected to elevated CO2 (520 ppm). After four months, an extreme climatic event (ECE) consisting of four weeks of reducted precipitation (-50%) followed by two weeks without irrigation combined with a heat wave (+6°C) were applied in three macrocosms at ambient CO2 and three macrocosms at elevated CO2. Then, all the macrocosms were irrigated to allow the vegetation to recover. The N content and in vitro parameters of rumen protein digestion were measured on plant samples collected before the extreme event (two cuts) and after recovery. Our results indicate that, irrespective of the sampling date, elevated CO2 results in a decrease in plant N content (P \u3c 0.01). Inversely, the application of the extreme event resulted in a large increase in N content (P \u3c 0.001) without a significant interaction with the CO2 effect. These changes significantly impacted ruminal protein digestion as evidenced by changes in the production of the fermentation end-products indicators of the proteolysis, namely ammonia and iso-volatile fatty acids. We conclude that several components of climate change can impact the nitrogenous quality of the forage and its use by ruminants

Cell wall component and mycotoxin moieties involved in binding of fumonisin B1 and B2 by lactic acid bacteria.

International audienceAims: The ability of lactic acid bacteria (LAB) to bind fumonisins B1 and B2 (FB1, FB2) in fermented foods and feeds and in the gastrointestinal tract could contribute to decrease their bioavailability and toxic effects on farm animals and humans. The aim of this work was to identify the bacterial cell wall component(s) and the functional group(s) of FB involved in the LAB-FB interaction. Methods and Results: The effect of physicochemical, enzymatic and genetic treatments of bacteria and the removal/inactivation of the functional groups of FB on toxin binding were evaluated. Treatments affecting the bacterial wall polysaccharides, lipids and proteins increased binding, while those degrading peptidoglycan (PG) partially decreased it. In addition, purified PG from Gram-positive bacteria bound FB in a manner analogue to that of intact LAB. For FB, tricarballylic acid (TCA) chains play a significant role in binding as hydrolysed FB had less affinity for LAB. Conclusions: Peptidoglycan and TCA are important components of LAB and FB, respectively, involved in the binding interaction. Significance and Impact of the Study: Lactic acid bacteria binding efficiency seems related to the peptide moiety structure of the PG. This information can be used to select probiotics with increased FB binding efficiency

Understanding the Effects of a Tannin Extract on Forage Protein Digestion in the Rumen and Abomasum Using a Dynamic Artificial Digestive System Coupled to a Digestomic Approach

Improving the use efficiency of dietary protein in ruminants is a major challenge to decrease feed supplementation and significantly decrease nitrogen (N) losses to the environment. The aim of this study was to characterize the effects of tannins on protein digestion in the rumen and in conditions simulating the abomasum, using a dynamic in vitro digestive system coupled to a digestomic approach. Three ruminally-cannulated sheep fed with alfalfa hay were infused daily with a solution of tannins, while three other sheep were infused with water (control). Standardized ruminal fluid was introduced into the digester, which simulated the transit of digesta under physicochemical conditions mimicking the abomasum in terms of pH regulation, digestive enzyme infusions and transit rate. Protein degradation in the rumen and in the simulated abomasum was analyzed by determination of fermentation end-products, and identification and quantification of peptides (Label Free Quantification) by LC-MS/MS high resolution (Orbitrap). The analysis of rumen samples showed that tannins result in a clear decrease of fermentation end-products related to protein degradation, namely ammonia (NH3) and iso-volatile fatty acids (VFA), and a greater abundance of the Rubisco, a major plant protein. In the simulated abomasal compartment, the peptidomic analysis showed that the hydrolysis intensity of Rubisco was higher in the presence of tannins compared to the control group. These results indicate that protein-tannin complexes could be dissociated in the physico-chemical conditions of the abomasum, increasing the flow of peptides to the intestine after protection of protein by tannins in the rumen

In vitro rumen fermentation of diets with different types of condensed tannins derived from sainfoin (Onobrychis viciifolia Scop.) pellets and hazelnut (Corylus avellana L.) pericarps

The aim of this study was to evaluate the in vitro rumen fermentation parameters of diets including pellets of sainfoin pellets and/or hazelnut pericarps, which are two plant resources that containing different types of condensed tannins (CT) with contrasted structures, using a batch culture system during for 24 h. The treatments were a basal diet (control), the basal diet + pellets of dehydrated sainfoin (PS), the basal diet + freeze-dried hazelnut pericarps (HP), and the basal diet + PS + HP. The diets were adjusted to be isotannic (20 g/kg dry matter (DM), except for the control) and isoproteic (132 g/kg DM). Total gas and methane (CH4) productions were measured after 3.5 h and 24 h of incubation. At the end of incubation, pH, in vitro DM degradability (IVDMD) and the concentration of fermentation end-products in the medium were also measured. The CT structures of CT infrom PS and HP were very different: as PS showed a PD-dominant profilehad mostly prodelphinidins and HP showed a PC-dominant profile mostly procyanidins. After 24 h of incubation, the total gas and methane productions and IVDMD were greater for the basal diet than for the diet + HP and the diet + PS (P<0.05). The CH4 production increased significantly with the diet + HP in the presence of PEG, a compound CT-inactivating CTcompound (P<0.001), and tended to increase for the diet + PS (P<0.1). The volatile fatty acids (VFA) net productions were globally similar among treatments, while the NH3 concentration was lower for the diet + PS (with a significant PEG effect) than for the diets including HP, and was the highest for the basal diet. It was concluded that the inclusion of PS and HP in a basal diet results in lower rumen fermentability and that but their CT decreased CH4 production and protein degradability;, PS being were more efficient effective than HP for the latterreducing protein degradability

Leguminosas bioactivas para mejorar el perfil lipídico de la carne de cordero

6 páginas, 2 figuras, 1 tabla.La utilización de leguminosas forrajeras en la dieta de los rumiantes puede ofrecer importantes ventajas. Además de su elevado valor proteico, algunas especies como la esparceta o el trébol rojo, contienen compuestos bioactivos que podrían mejorar la calidad nutricional de la carne. Entre ellos, destacan los taninos en la esparceta y la polifenol oxidasa en el trébol rojo. Ahora bien, la climatología de muchas áreas limita su aprovechamiento en verde. En este estudio, mostramos que la utilización de la esparceta y el trébol rojo conservados mediante ensilado podría ser una buena alternativa para la alimentación de corderos, al aumentar la concentración de ácidos grasos poliinsaturados (PUFA) en la carne a través de su efecto sobre el metabolismo lipídico ruminal. Aunque el mecanismo de acción de los compuestos bioactivos presentes en estos forrajes probablemente sea distinto, sus efectos sobre el perfil de ácidos grasos de la carne parecen ser similares y aditivos.Este trabajo forma parte del proyecto Legume Plus, financiado por la Comisión Europea a través de una Red de Formación Inicial Marie Curie (PITN GA- 2011- 289377) PG . Toral disfruta de un contrato Ramón y Cajal, financiado por el Ministerio de Economía, lndustria y Competitividad.Peer reviewe

Sodium hydroxide enhances extractability and analysis of proanthocyanidins in ensiled sainfoin (onobrychis viciifolia)

Little information exists on the effects of ensiling on condensed tannins or proanthocyanidins. The acetone–butanol–HCl assay is suitable for measuring proanthocyanidin contents in a wide range of samples, silages included, but provides limited information on proanthocyanidin composition, which is of interest for deciphering the relationships between tannins and their bioactivities in terms of animal nutrition or health. Degradation with benzyl mercaptan (thiolysis) provides information on proanthocyanidin composition, but proanthocyanidins in several sainfoin silages have proved resistant to thiolysis. We now report that a pretreatment step with sodium hydroxide prior to thiolysis was needed to enable their analysis. This alkaline treatment increased their extractability from ensiled sainfoin and facilitated especially the release of larger proanthocyanidins. Ensiling reduced assayable proanthocyanidins by 29%, but the composition of the remaining proanthocyanidins in silage resembled that of the fresh plants

Impact of tannin supplementation on proteolysis during post-ruminal digestion in wethers using a dynamic in vitro system: a plant (Medicago sativa) digestomic approach

The aim of this study was to characterize the effects of tannins on plant protein during sheep digestion, using a digestomic approach combining in vivo (rumen) conditions and an in vitro digestive system (abomasum and small intestine). Ruminal fluid from wethers infused with a tannin solution or water (control) was introduced into the digester, and protein degradation was followed by LC-MS/MS. Tannin infusion in the rumen led to a clear decrease in protein degradation-related fermentation end-products, whereas RuBisCo protein was more abundant than in control wethers. In the simulated abomasum, peptidomic analysis showed more degradation products of RuBisCo in the presence of tannins. The effect of RuBisCo protection by tannins continued to impact Rubisco digestion into early-stage intestinal digestion, but was no longer detectable in late-stage intestinal digestion. The peptidomics approach proved a potent tool for identifying and quantifying the type of protein hydrolyzed throughout the gastrointestinal tract

Isolation and Identification of a Strain of Aspergillus Tubingensis With Deoxynivalenol Biotransformation Capability

Deoxynivalenol (DON) is one of the most common contaminants of various foodstuffs. A biotransformation system was used in order to lessen the toxicity of DON. A strain of Aspergillus (NJA-1) was isolated from soil and cultured in an inorganic salt medium containing DON. Bt2a/Bt2b primers were used to amplify the β-tubulin gene of NJA-1. Sequence analysis the PCR product and morphology observation indicated that NJA-1 belonged to Aspergillus tubingensis (aerobic fungi). The DNA sequence information of the PCR product was deposited in GenBank (accession number DQ9025790). The DNA sequence had 99% similarity to the Aspergillus tubingensis accession number AY820009. An unknown compound in NJA-1 showed the ability to convert DON into another product. The molecular weight of the bioconversion product was 18.1 D (H2O) larger than that of DON. The analysis showed that DON could be hydrolyzed by NJA-1. The mean DON biotransformation rate was 94.4% after two weeks of cultivation. The finding presents a new method for DON biotransformation

Benefits of condensed tannins in forage legumes fed to ruminants:Importance of structure, concentration, and diet composition

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 (Onobrychis Mill. 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

Biodegradation of ochratoxin A by Pediococcus parvulus isolated from Douro wines

Lactic acid bacteria (LAB) are a promising solution to reduce exposure to dietary mycotoxins because of the unique mycotoxin decontaminating characteristic of some LAB. Ochratoxin A (OTA) is one of the most prominent mycotoxins found in agricultural commodities. The present work reports on the ability of Pediococcus parvulus strains that were isolated from Douro wines that spontaneously underwent malolactic fermentation to detoxify OTA. These strains were identified and characterised using a polyphasic approach that employed both phenotypic and genotypic methods. When cultivated on OTA-supplemented MRS media, OTA was biodegraded into OTα by certain P. parvulus strains. The presence of OTα was confirmed using LC-MS/MS. The conversion of OTA into OTα indicates that the OTA amide bond was hydrolysed by a putative peptidase. The rate of OTA biodegradation was found to be dependent on the inoculum size and on the incubation temperature. Adsorption assays with dead P. parvulus cells showed that approximately 1.3% ± 1.0 of the OTA was adsorbed onto cells wall, which excludes this mechanism in the elimination of OTA by strains that degrades OTA. Under optimum conditions, 50% and 90% of OTA was degraded in 6 and 19 h, respectively. Other LAB strains that belonged to different species were tested but did not degrade OTA. OTA biodegradation by P. parvulus UTAD 473 was observed in grape must. Because some P. parvulus strains have relevant probiotic properties, the strains that were identified could be particularly relevant to food and feed applications to counteract the toxic effects of OTA.This work was funded by FEDER funds through the "Programa Operacional Factores de Competitividade - COMPETE" and by national funds through "Fundacao para a Ciencia e a Tecnologia - FCT", Ref. FCOMP-01-0124-FEDER-028029 and PTDC/AGR-TEC/3900/2012, respectively. The authors also thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from FCT