Dactylis Glomerata Research Articles

Chemical form of volatilized iodine obtained from orchard grass (Dactylis glomerata L.).

Japan's first commercial nuclear fuel reprocessing plant is expected to release radioiodine into the atmosphere, and orchard grass plants grown in the vicinity of this plant may absorb this radioiodine. In this study, we investigated the mechanism underlying the absorption and volatilization of iodine in the leaves of orchard grass. Our findings suggest that iodine can be transferred from the leaves of this grass to the atmosphere via two routes: direct volatilization and absorption followed by volatilization. Previous studies on rice and oats also show that iodine can be absorbed by the roots and volatilized from the plant's body. Although orchard grass absorbs iodine via the leaves, the chemical form of volatilized iodine may differ from that absorbed via the roots. We applied a NaI solution to the leaves of orchard grass and analyzed the volatilized iodine. The experimental results showed that the iodine was volatilized as methyl iodide.

Animal behaviour and dietary preference of dairy cows grazing binary and diverse pastures under the leaf regrowth stage defoliation criterion

In New Zealand, intensively managed pasture-based dairy systems rely on binary pastures mostly comprised of Lolium perenne L. and Trifolium repens L.. More frequent and extreme climatic events have been negatively affecting the persistency and production of these pastures, which now present increased seasonality, with marked peaks and troughs of production throughout the year. Diversification of plant species offers a solution to deal with increased seasonality. However, little is known about animal behaviour and dietary preferences of dairy cows grazing diverse pastures. The present study aimed to assess the grazing preferences of dairy cows when unrestrictedly offered binary (L. perenne and T. repens; Bi) and diverse pastures (L. perenne, Bromus valdivianus Phil., Dactylis glomerata L. and T. repens; Mix) subjected to three different leaf regrowth stage (LS) defoliation criteria. Secondarily, the study aimed to determine the main plant-related drivers for any potential animal preference. The treatments were MixLp (defoliated at L. perenne LS), BiLp (defoliated every time MixLp was defoliated), MixBv (defoliated at B. valdivianus LS) and BiBv (defoliated every time MixBv was defoliated), MixDg (defoliated at D. glomerata LS) and BiDg (defoliated every time MixDg was defoliated). Dairy cattle were evaluated over five agricultural seasons. The response variables were grazing time and location, bite rate, animal behavioural activity, pre-grazing herbage mass, undisturbed sward height, lamina:stem ratio, crude protein, metabolisable energy, organic matter digestibility, non-structural carbohydrates, neutral detergent fibre and lignin. Where significant differences were found, binary pastures presented lower sward height and higher non-structural carbohydrate content in comparison to the diverse pastures under the same LS defoliation criteria. However, no significant differences were found in the percentage of time that cows spent grazing both pastures. Season was the greatest contributor to the proportion variation found in all response variables, with values ranging from 47.55 % up to 88.77 %. In winter and spring, cows modulated their grazing behaviour (proportional time spent grazing, ruminating, or idling), investing more time actively grazing pastures under L. perenne LS interval of defoliation (2.5–3.0 LS), the criterion which resulted in shorter grazing rotations. This study allowed us to understand the suitability of diverse pastures from an animal perspective, and highlighted that independent of the pasture type, the positive productive and nutritional effects of defoliation management based on the LS may also extend themselves to positive outcomes in animal preference, interpreted as the percentage of time dairy cows spend grazing rather than ruminating or idling across and within seasons.

Plant responses to urban gradients: Extinction, plasticity, adaptation

Abstract Biodiversity‐oriented urban management and planning require information on the drivers of wildlife composition and ecosystem function within cities. Urban landscapes impose environmental gradients along which species may be filtered away, or respond by showing adaptive variation in functional trait values. Such trait variation may in turn be due to a species' phenotypic plasticity, or a consequence of microevolution leading to local adaptation. This study investigates three possible plant responses to urban environmental gradients, with different evolutionary consequences: extinction, plasticity and adaptation. We assessed whether individual functional traits (LMA—leaf mass per area, plant height and flower length), population performance traits (seed mass and germination rate), as well as species frequency in the plant community, responded to gradients in mowing frequency, soil fertility and structure, temperature and surrounding mean building height, among four herbaceous plant species present in the metropolitan area of Strasbourg. Using a common garden experiment, we tested whether the observed trait variation was hereditary, and may thus constitute evidence for local adaptation. Our results detected the three types of expected responses. Plantago lanceolata is plastic to urban gradients, and Trifolium pratense showed both plastic and hereditary responses. Dactylis glomerata and Medicago lupulina showed all three responses: they both declined under increasing mowing frequency, were plastic to surrounding mean building height, and showed hereditary responses to different urban gradients. Urban management and planning therefore impact on the evolutionary capabilities of plants in cities. In the case of management this is highlighted by the detected trends in species' traits and frequency in response to mowing. The consequences of urban planning are evidenced by mean building height eliciting most often plastic and adaptive responses. Synthesis. Herbaceous plants often change their morphology in response to urban conditions: grass cutting, altered soils, warmer temperatures and being surrounded by tightly packed buildings. These changes are sometimes hereditary, which suggests that city management and planning affect the ability of plants to survive and evolve in urban environments.

Spring nitrogen and plant growth regulator effects on seed yield of orchardgrass

AbstractOrchardgrass (Dactylis glomerata L.) is an important forage seed crop, but unlike other cool‐season grasses, seed yields have not increased over time. Seed yield increases in orchardgrass may be possible with plant growth regulators (PGRs) such as trinexapac‐ethyl (TE) and chlormequat chloride (CCC). Field trials were conducted at Hyslop Experimental Farm near Corvallis, Oregon, over three crop years (2017–2019) to examine the effects of spring nitrogen (N) and PGRs on seed production characteristics in orchardgrass. Spring N treatments included 0, 112, 157, and 202 kg N ha−1 and PGR applications were timed using the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale. Four PGR treatments included an untreated control, 210 g TE ha−1 at BBCH 32, 210 g TE ha−1 at BBCH 51, and 105 g TE ha−1 + 1500 g CCC ha−1 at BBCH 32. An interaction of spring N and PGR increased seed yields in 2 years, while spring N and PGR increased seed yield independently in the other year. The combination of TE and CCC PGRs did not increase seed yield over TE alone. Seed yield increases from spring N were due to an increase in seed number m−2, while increases in seed yield attributable to PGRs were the result of increased seed number m−2 and harvest index. This study suggests that the combination of 112 kg ha−1 spring N and 210 g ha−1 TE PGR is the best practice to maximize seed yield in orchardgrass.

From wastewater to feed: Understanding per- and polyfluoroalkyl substances occurrence in wastewater-irrigated crops.

Reusing treated wastewater for irrigation is a sustainable way to recycle nutrients and reduce freshwater use. However, wastewater irrigation inadvertently introduces per- and polyfluoroalkyl substances (PFAS) into agroecosystems, causing concerns regarding potential adverse effects to ecosystem, animal, and human health. Therefore, a better understanding of the pathways by which PFAS accumulate in forage crops is needed. A greenhouse study was conducted to (1) quantify the contribution of root uptake versus foliar sorption of PFAS in corn (Zea mays) and orchard grass (Dactylis glomerata), (2) assess effects of PFAS-impacted wastewater irrigation on plant health, and (3) determine the potential implications for bioaccumulation. The greenhouse study was composed of four treatments for each forage crop to isolate the relative contribution of two uptake pathways. Results suggested that foliar sorption was an unlikely contributor to PFAS concentrations observed in crop tissue. Root uptake was identified as the predominant uptake pathway. PFAS were detected more frequently in orchard grass samples compared to corn silage samples. Additionally, corn exhibited a lower uptake of long-chain PFAS compared to grass. Overall, no plant health effects on growth attributable to PFAS concentrations were observed.Forage data suggest cattle exposure to PFAS would be largely short-chain PFAS or long-chain "replacement" compounds(>50%). However, cattle may still be exposed to potentially harmful long-chain PFAS; levels in the forage crops exceeded the tolerable weekly intake set by the European Food Safety Authority. This study provides insights on PFAS entry into the food chain and potential implications for livestock and human health.

Tetracycline but not sulfamethazine inhibits early root growth of wild grassland species, while seed germination is hardly affected by either antibiotic

Seed germination and early growth of grassland species might be influenced by veterinary antibiotics that are extensively released into agricultural habitats. Therefore, we tested impacts of the commonly used antibiotics tetracycline and sulfamethazine, single and in mixture, on seed germination and seedling root growth of six typical species of temperate European grasslands (Carum carvi, Centaurea jacea, Galium mollugo, Plantago lanceolata, Silene latifolia, Dactylis glomerata). In standardised germination experiments, we assessed three germination variables (germination percentage, mean germination time, synchrony of germination) and one post-germination variable (seedling root length) under different environmentally realistic antibiotic concentrations (0.1, 1, 10 mg l−1 and a water control). While the germination variables were only irregularly and weakly affected by both antibiotics, seedling root length was strongly reduced by tetracycline, but not by sulfamethazine. Among the test species, D. glomerata was most sensitive to tetracycline with the average root length reduced up to 81 % in the 10 mg l−1 treatment. Its germination behaviour, however, was almost insensitive to the two antibiotics. Mixture effects were only shown in relation to the germination of single species, where the binary mixture produced effects but not the two single antibiotics or, conversely, effects of single antibiotics were lost in the mixture. These findings highlight the potential threat of plant regeneration from seed by veterinary antibiotics, particularly affecting early root growth and potentially influencing plant population growth in natural habitats.

Genome-wide association analysis reveals novel candidate loci and a gene regulating tiller number in orchardgrass

Tillers are specialized lateral shoots arising from axillary buds at basal nodes, and are also an important agronomic trait that determines the aboveground biomass and grain yield of various gramineous crops. So far, few genes have been reported to control tiller formation and most have been in the annual crop rice (Oryza sativa). Orchardgrass (Dactylis glomerata) is an important perennial forage crop with great economic and ecological value, but its genes regulating tillering have remained largely unknown. In the present study, we used a natural population of 264 global orchardgrass germplasms to determine genes associated with quantitative variation in tiller number through genome-wide association study analysis. A total of 19 putative loci and 55 genes associated with tiller number were thus identified. Additionally, 26 putative differentially expressed genes with tiller number, including DgCYC-C1, were identified by RNA-seq and genome-wide association study analysis. DgCYC-C1 which is involved in cell division, was overexpressed, revealing that DgCYC-C1 positively regulates tiller number. These results provide some new candidate genes or loci for the improvement of tiller number in crops, which might advance new sustainable strategies to meet global crop production challenges.

Exploring microbial diversity and function in companion planting systems of white clover and orchard grass

Companion planting of white clover (Trifolium repens L.) with orchard grass (Dactylis glomerata L.), a famous hay grass, improves the forage quality of orchard grass. Microbiome profiling techniques can reveal the specific role of white clover companion planting with orchard grass. This study aimed to explore the microbiome distribution and gene functions of rhizosphere and non-rhizosphere soil via companion planting systems of white clover and orchard grass. From metagenomics sequencing analysis, we confirmed the significant role of white clover on soil environment modeling during companion planting with orchard grass. Twenty-eight biomarkers of rhizosphere soil organisms were identified during companion planting, including Proteobacteria, Betaproteobacteria, Flavobacteriia, and Caulobacterales. The number of gene functions of nitrogen and carbon fixation in companion planting was higher than that in single plants, indicating new functional flora for companion planting. We characterized specific rhizosphere effects, typical biomarker flora, and potential regulatory mechanisms for white clover-related companion planting by metagenomics analyses.

PSV-26 Effect of addition of Ascophyllum nodosum and Asparagopsis taxiformis, alone or in combination, to an herbage-based diet on in vitro fermentation in continuous culture

Abstract This study investigated the effect of individual or simultaneous addition of two macroalgae species on in vitro fermentation in continuous culture. Four single-flow continuous culture fermentors were fed an orchardgrass herbage-based (orchardgrass; Dactylis glomerata L.) basal diet and randomly assigned one of four treatments: 1) control (CON), no macroalgae addition; 2) Ascophyllum nodosum dosed at 2.5% dry matter (DM; ASC); 3) Asparagopsis taxiformis dosed at 0.5% DM (ATX); and 4) A. nodosum (2.5% DM) + A. taxiformis (0.5% DM) dosed simultaneously (AS+AT). Four experimental periods were conducted in a randomized block design with 7 d of treatment adaptation and 3 d of sample collection. Fermentors were fed 82 g of DM per day in 4 equal feedings. In the last 3 d of each experimental period, daily samples of total effluent were taken for analyses of ammonia N and volatile fatty acids (VFA). Effluent was composited by fermentor and analyzed for DM, ash, neutral and acid detergent fiber, and crude protein. Purine concentrations of effluent and bacterial isolates were determined to estimate partitioning of N flow into feed, bacterial, and ammonia N fractions. Methane (CH4) emissions were measured in each fermentor every 15 min using a Fourier transform infrared gas analyzer, and pH was recorded every 2 min. Data were analyzed using the MIXED procedure of SAS v 9.4 with pre-planned contrasts comparing each individual macroalgae to CON (CON vs. ASC and CON vs. ATX) and comparing A. taxiformis with and without simultaneous addition of A. nodosum (ATX vs. AS+AT). Significance was declared at P ≤ 0.05 and tendencies at 0.05 < P ≤ 0.10. Nutrient digestibilities, CH4 emissions, pH, and N metabolism variables were not affected (P > 0.10) in ASC compared with CON, but total VFA concentration increased (P < 0.05) by 10%. Contrarily, the ATX diet tended (P = 0.61) to have reduced true organic matter digestibility, reduced (P < 0.05) total VFA concentration by 11%, and reduced (P < 0.05) CH4 production by 99.9% versus CON. Simultaneous the combination of microalgae (AS+AT) did not further reduce (P > 0.10) nutrient digestibility or total VFA concentration compared with ATX, and did not change (P > 0.10) the degree of CH4 inhibition. However, A. nodosum did not mitigate (P > 0.10) any of the negative effects on fermentation associated with A. taxiformis, as nutrient digestibilities and N metabolism variables in AS+AT were also not different (P > 0.10) from ATX. While the macroalgae species, A. nodosum and A. taxiformis, led to different fermentation patterns when added individually to continuous culture fermentors, no negative or positive interactions were observed from their simultaneous addition.

222 Validation of Brix for predicting sugar concentration of alfalfa and orchardgrass

Abstract The objective of this study was to evaluate the accuracy of Brix in predicting sugar concentrations in fresh alfalfa (Medicago sativa L.; ALF) and orchardgrass (Dactylis glomerata L.; OG) forages to be used as an inexpensive and rapid field-level assessment of relative energy in forages. In a 2-yr study, fresh forages samples from ALF and OG monoculture pastures in central Pennsylvania, U.S. were collected once monthly from May to September. Samples were immediately evaluated for Brix values with a hand-held digital refractometer, and the remaining biomass was frozen immediately with liquid N to halt cellular respiration. Samples were lyophilized and analyzed for individual sugars and wet chemistry nutritive analyses. Brix values were correlated with wet chemistry analyses using the PROC CORR procedure in SAS, with significance established at P < 0.05. Brix was positively correlated (P < 0.05) with total and individual sugars in ALF during late spring and late summer (0.49 to 0.93), but correlations were non-existent (P > 0.05) or negative (-0.55 to -0.73; P < 0.05) in mid-summer. Brix values had moderate to strong negative correlations (P < 0.05) to NDF and ADF in ALF (-0.57 to -0.71). Conversely, Brix values did not correlate (P > 0.05) to any notable sugar parameters in OG beyond the first sampling date (0.60 to 0.74; P < 0.05). Brix was not correlated (P > 0.05) to NDF and ADF in OG. In summary, Brix values did not consistently predict sugar concentrations in fresh ALF and OG forages. Because Brix measures dissolved solids in solution (not just sugars), Brix readings collected from crushed ALF or OG samples may be confounded by fibrous fractions found in the solution as well as decreased sugar concentrations compared with fruit crops. Brix accuracy may also be dependent on seasonal temperature patterns, plant growth stage, and daily weather patterns. Other solutions should be investigated that rapidly assess sugar profiles and nutritive values of fresh forages.

Species dynamics in forage seed mixtures exposed to different lengths of growing season

AbstractSix seed mixtures differing in number of species and their proportion of timothy (Phleum pratense L.) were tested during three/four production (ley) years in replicated field experiments at three climatically different sites in Norway; one a mountainous inland site at 61° N (Løken) and two in coastal environments, at 61° N (Fureneset) and 65° N (Tjøtta). There were significant differences in forage accumulation (FA) and digestible forage accumulation (DFA) between the three sites. There was a significant FA decline from the third to the fourth ley year for mixtures containing timothy, but not for mixtures without timothy. Estimated interannual FA‐ stability was higher for timothy‐based seed mixtures than for mixtures without timothy at the inland site, but FA‐stability was lower at the coastal sites. In the third‐year herbage of timothy‐based mixtures at the inland site consisted almost solely of timothy, whereas at the coastal sites meadow fescue (Festuca pratensis Huds.) and especially tall fescue (F. arundinacea Schreb.) dominated. In seed mixtures without timothy, cocksfoot (Dactylis glomerata L.) suppressed other species at the inland site, whereas at the coastal sites, tall fescue and ryegrasses (Lolium spp.) were the dominant species in the third‐year herbage. Length of growing season and site‐specific growing conditions were important drivers for the observed species changes. Timothy can thus be recommended for ley establishment at sites where the growing season is short (<4 months) and plant growth is intensive, but under conditions with a longer growing season it needs to be sown in mixtures with grass species that surpass the regrowth capacity of timothy.

Phenological Analysis of Grasses (Poaceae) in Comparison with Aerobiological Data in Moscow (Russia).

Grasses (Poaceae) produce large amounts of pollen and are among the main causes of pollinosis worldwide. Despite their morphological similarity, pollen grains of different grass species may have different allergenicities. Therefore, quantification of the roles of individual species in airborne pollen is an important task. There are very few studies on this topic, and none of them have been conducted in a temperate continental climate. Our study was carried out for three years (2020-2022) in the urban territory of Moscow (Russia) and aimed to understand what grass species contribute the most to the total pollen load of the atmosphere. The comparison of aerobiological and phenological data was based on calculating the phenological index, which is a combination of phenological parameters, pollen productivity of individual species, and their abundance. Our data showed that the decomposition of pollination curves based on the phenological index was sometimes very efficient but not always possible in temperate continental climates. The main reasons for disagreement between aerobiological and phenological data were weather conditions and lawn mowing. Not all grasses were equally important as sources of allergenic pollen. The greatest contribution to the pollen load at the beginning of the season in Moscow was made by Dactylis glomerata, and to a lesser extent by Phleum pratense and Festuca pratensis. These are the most common species, which are widespread throughout Europe. The contribution of minor components is insignificant.

The LTAR Cropland Common Experiment in the Upper Chesapeake Bay.

Dairy production is a key agricultural enterprise in the Upper Chesapeake Bay (UCB) basin, where phosphorous (P) and nitrogen (N) loading contribute to eutrophication. Import of forages and grains and application of mineral fertilizers contribute to nutrient imbalances in the basin. The UCB Long-Term Agroecosystem Research Cropland Common Experiment aims to evaluate diverse crop rotations that minimize the need for imported feed, maximize year-round living cover, and reduce nutrient losses. UCB's plot-scale experiment was established in 2018, incorporating an ongoing cropping system study that was established by the Pennsylvania State University in 2010. An alternative dairy cropping rotation (including silage and grain corn [Zea mayes L.], alfalfa [Medicago sativa L.]/orchardgrass [Dactylis glomerata L.] mix, winter rye silage [Secale cereale L.], and sorghum-sudangrass [Sorghum × drummondii (Steud.) Millsp. & Chas]) that employed manure injection, integrated pest management, and less frequent manure application was compared to a prevailing, conventionally managed silage corn-alfalfa rotation with higher manure application rates. A field-scale experiment was established in 2019 to monitor alternative production practices (manure injection and avoidance of neonicotinoid seed treatment) and prevailing practices in three fields on a commercial dairy farm. Findings suggest that crop rotation diversification, manure injection, and integrated pest management have the potential to increase the economic and environmental sustainability of dairy cropping systems, but long-term evaluation is needed for confirmation.

The Effect of Drought on Agronomic and Plant Physiological Characteristics of Cocksfoot (Dactylis glomerata L.) Cultivars

The Effect of Drought on Agronomic and Plant Physiological Characteristics of Cocksfoot (Dactylis glomerata L.) Cultivars

Combined Genome-Wide Association Study and Transcriptome Analysis Reveal Candidate Genes for Resistance to Rust (Puccinia graminis) in Dactylis glomerata.

Rust disease is a common plant disease that can cause wilting, slow growth of plant leaves, and even affect the growth and development of plants. Orchardgrass (Dactylis glomerata L.) is native to temperate regions of Europe, which has been introduced as a superior forage grass in temperate regions worldwide. Orchardgrass has rich genetic diversity and is widely distributed in the world, which may contain rust resistance genes not found in other crops. Therefore, we collected a total of 333 orchardgrass accessions from different regions around the world. Through a genome-wide association study (GWAS) analysis conducted in four different environments, 91 genes that overlap or are adjacent to significant single nucleotide polymorphisms (SNPs) were identified as potential rust disease resistance genes. Combining transcriptome data from susceptible (PI292589) and resistant (PI251814) accessions, the GWAS candidate gene DG5C04160.1 encoding glutathione S-transferase (GST) was found to be important for orchardgrass rust (Puccinia graminis) resistance. Interestingly, by comparing the number of GST gene family members in seven species, it was found that orchardgrass has the most GST gene family members, containing 119 GST genes. Among them, 23 GST genes showed significant differential expression after inoculation with the rust pathogen in resistant and susceptible accessions; 82% of the genes still showed significantly increased expression 14 days after inoculation in resistant accessions, while the expression level significantly decreased in susceptible accessions. These results indicate that GST genes play an important role in orchardgrass resistance to rust (P. graminis) stress by encoding GST to reduce its oxidative stress response.

The Effect of Biological Secondary Treated Domestic Wastewater on Agronomic Properties and Element Content of Some Forage Plants

Aims: This study was carried out to determine the effect of domestic advanced biological treated domestik wastewater on the agronomic properties and nutritional content of some forage crops, as a result of the increasing interest in the use of treated wastewater in agriculture. Material and methods: Biologically treated domestic wastewater was diluted with 25%, 50% and 75% pure water and applied to crested wheatgrass (Agropyron cristatum Geartn), orchard grass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) pots according to field capacity. Results: Alfalfa, orchard grass and crested wheatgrass plants were used as trial plants. The effect of the diluted wastewater application on the height of crested wheatgrass, orchard grass and alfalfa was significant. From the first mow, alfalfa and orchard grass had increased green and dry weights per pot, with the most marked increase for alfalfa. The wastewater ratios caused an increase in nutrient and metal concentrations in the three plants, while a decrease in the Se concentration in alfalfa and crested wheatgrass. Diluted wastewater not effected alfalfa Ca concentration significantly. While the dilute wastewater significantly and positively effected the relationship of orchard grass with all elements, but Se affected negatively. Soil organic matter and electrical conductivity increased and pH decreased with increasing wastewater ratio. Discussion: Diluted domestic water application played an important role in nutrient and metal concentrations by mediating increased plant element uptake associated with soil organic matter and electrical conductivity responses. Conclusions: However, long-term field studies are required to determine the dilution rate at which the salinity risk threshold can be determined.

Orchard grass (Dactylis glomerata L.) yield and nutritive characteristics in response to different cutting regimes in a temperate region

The present study was carried out at the Research Farm of Regional Research Station, ICAR-IGFRI, Rangreth, Srinagar, to evaluate three harvesting stages and three cutting intervals for achieving higher fodder yield and quality in orchard grass (Dactylis glomerata L). Among the harvesting stages, H3 (harvesting at the flowering stage) recorded the highest green (27.04 t/ha) and dry(8.05 t/ha) fodder yield. Among the cutting intervals, CI 3 (cutting at 60-day intervals) recorded higher fresh and dry biomass yield. Fodder yield increased with harvesting at later stages and increased cutting intervals. The highest crude protein content (11.87%), lowest NDF (55.87%) and ADF (31.65%) contents were recorded when grass was harvested at the vegetative stage. Digestible dry matter (DDM) varied significantly with both harvesting stage and cutting interval and was found to be highest with H1 (64.23%) and CI 1 (63.54%). The highest relative feed value (RFV) of 106.92% and highest total digestible nutrients (TDN) of 65.68% were found in the orchard grass cut at the vegetative stage (H1), which was at par with orchard grass harvested first at the booting stage (H2). Harvesting at both vegetative and booting stages resulted in good quality (RFV >103%) and energy-rich (TDN> 65%) forage. Harvesting at the flowering stage resulted in fair quality (RFV 96.67% and TDN 63.65%) fodder.

Grass pollen allergoids conjugated with mannan for subcutaneous and sublingual immunotherapy: a dose-finding study.

Polymerized allergoids conjugated with mannan represent a novel approach of allergen immunotherapy targeting dendritic cells. In this study, we aimed to determine the optimal dose of mannan-allergoid conjugates derived from grass pollen (Phleum pratense and Dactylis glomerata) administered via either the subcutaneous or sublingual route. A randomized, double-blind, placebo-controlled trial with a double-dummy design was conducted, involving 162 participants across 12 centers in Spain. Subjects were randomly allocated to one of nine different treatment groups, each receiving either placebo or active treatment at doses of 500, 1,000, 3,000, or 5,000 mTU/mL over four months. Each participant received five subcutaneous (SC) doses of 0.5 mL each, every 30 days, and a daily sublingual (SL) dose of 0.2 mL. Participants who received active treatment through SC, received placebo through SL. Participants who received active treatment through SL, received placebo SC. One Group, as control, received bot SC and SL placebo. The primary efficacy outcome was the improvement in titrated nasal provocation tests (NPT) at the end of the study compared to baseline. Secondary outcomes included specific antibody (IgG4, IgE) and cellular (IL-10 producing and regulatory T cell) responses. All adverse events and side reactions were recorded and assessed. Post-treatment, the active groups showed improvements in NPT ranging from 33% to 53%, with the highest doses showing the greatest improvements regardless of the administration route. In comparison, the placebo group showed a 12% improvement. Significant differences over placebo were observed at doses of 3,000 mTU/mL (p=0.049 for SL, p=0.015 for SC) and 5,000 mTU/mL (p=0.011 for SL, p=0.015 for SC). A dose-dependent increase in IgG4 was observed following SC administration, and an increase in IL-10 producing cells for both routes of administration. No serious systemic or local adverse reactions were recorded, and no adrenaline was required. Grass pollen immunotherapy with mannan-allergoid conjugates was found to be safe and efficacious in achieving the primary outcome, whether administered via the subcutaneous or sublingual routes, at doses of 3,000 and 5,000 mTU/mL. https://www.clinicaltrialsregister.eu/ctr-search (EudraCT), identifier 2014-005471-88; https://www.clinicaltrials.gov, identifier NCT02654223.

Perennial grass and herb options to extend summer–autumn forage in a drought‐prone temperate environment

AbstractBackgroundThe ability to finish livestock on pasture over the summer–autumn period could improve the profitability of red meat enterprises in drought‐prone temperate regions. In south‐eastern Australia, traditional perennial options are limited by poor warm‐season performance (phalaris, Phalaris aquatica L.) and widespread environmental constraints (lucerne, Medicago sativa L.). We aimed to identify perennial species suitable for summer–autumn finishing.MethodsWe tested pure swards of summer‐active perennial grasses and herbs (20 cultivars across 14 species) in replicated small‐plot experiments at two sites on the Southern Tablelands of New South Wales, Australia. We assessed early persistence, productivity and warm‐season nutritive characteristics over 2–3 years.ResultsLucerne and chicory (Cichorium intybus L.) persisted well through drought and produced herbage of high quantity and quality through summer–autumn. Digit grass (Digitaria eriantha Steud.) was highly persistent and productive but nutritive values were generally poor. Cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and plantain (Plantago lanceolata L.) were productive but less persistent through drought, while nutritive values were sometimes inadequate.ConclusionsChicory is a good alternative to lucerne, given its excellent summer–autumn performance, ability to survive droughts and superior acid soil tolerance. If appropriate management resolves issues with persistence and nutritive value, several of the other species could also be used to close the warm‐season feed gap in drought‐prone temperate environments.

Genotype × environment interaction patterns of dry matter yield in meadow brome, orchardgrass, tall fescue, and timothy evaluated at harsh winter sites

AbstractBackgroundGenotype × environment interaction (GEI) slows genetic gains and complicates selection decisions in plant breeding programs. Forage breeding program seed sales often encompass large geographic regions to which the cultivars may not be adapted. An understanding of the extent of GEI in perennial, cool‐season forage grasses will facilitate improved selection decisions and end‐use in areas with harsh winters.MethodsWe evaluated the dry matter yield of nine meadow brome (Bromus biebersteinii Roemer & J. A. Schultes), nine orchardgrass (Dactylis glomerata L.), seven tall fescue (Lolium arundinaceum (Schreb.) Darbysh.), and 10 timothy (Phleum pratense L.) cultivars or breeding populations at seven high latitude and/or elevation locations in Canada and the United States from 2019 to 2021.ResultsFor each of the species, we found significant differences among the genotypes for dry matter yield across environments and found significant levels of GEI. Using site regression analysis and GGE biplot visualizations, we then characterized the extent of the interactions in each species. Except for tall fescue, there was little evidence for the broad adaptation of genotypes across locations.ConclusionsThis research adds further evidence to the limitations of perennial, forage breeding programs to develop widely adapted cultivars and the need to maintain regional breeding efforts.