Biology, genetics, and management of ergot (Claviceps spp.) in rye, sorghum, and pearl millet

Examination of Salmonella Prevalence in Pigs Through Rye-Based Feeding and Coarser Feed Structure Under Field Conditions

INTRODUCTION

Salmonellosis is the second most commonly occurring bacterial zoonosis in Germany. Rye in pig feeding offers new possibilities for addressing that issue due to its high content of non-starch polysaccharides (NSPs). These are fermented in the intestinal tract to specific fermentation products, which seem to have bacteriolytic effects against Salmonella. A coarse feed structure can display synergistic effects.

METHODS

Seven conventional pig fattening farms increased the rye content (40%-70%) while limiting the amount of fine particles (maximum of 20% ≤0.25 mm). Samples from pigs were tested for Salmonella antibodies and compared with samples from 167 farms without any changes to the feed.

RESULTS

Rye-based diets had a significant (p < 0.05) impact on Salmonella antibody (percentage optical density [OD%]) detection. In this study, it became apparent that significantly fewer positive OD% values could be detected due to the increase in rye compared to farms that did not change the feed (Farm 6 P0: 35.45 ± 36.18; P1: 15.48 ± 16.98; P2: 9.36 ± 8.17). An elimination of Salmonella could not be achieved, but especially farms with high antibody counts were able to strongly reduce those in both phases consecutively (Farm 5 P0: 35.17 ± 35.53; P1: 18.56a ± 20.96; P2: 13.38a ± 18.99). That was different on farms without adapted feeding, where an increase in Salmonella antibodies was observed (P0: 17.38 ± 22.21; P1: 20.12 ± 25.39; P2: 18.12 ± 25.44).

CONCLUSION

By increasing the proportion of rye and limiting the proportion of fine particles in the feed, Salmonella antibodies (OD% values) in meat juice and blood can be significantly reduced, especially on farms with an initially high incidence of Salmonella. If that is implemented in feeding across the board on farms, an improvement in food safety and a decreased risk of zoonosis can be expected.

The C-8-S-isomers of ergot alkaloids - a review of biological and analytical aspects

Ergot alkaloids are secondary metabolites that are produced by fungi and contaminate cereal crops and grasses. The ergot alkaloids produced by Claviceps purpurea are the most abundant worldwide. The metabolites exist in two configurations, the C-8-R-isomer (R-epimer) and the C-8-S-isomer (S-epimer). These two configurations can interconvert to one another. Ergot alkaloids cause toxic effects after consumption of ergot-contaminated food and feed at various concentrations. For bioactivity reasons, the C-8-R-isomers have been studied to a greater extent than the C-8-S-isomer since the C-8-S-isomers were considered biologically inactive. However, recent studies suggest the contrary. Analytical assessment of ergot alkaloids now includes the C-8-S-isomers and high concentrations of specific C-8-S-isomers have been identified. The inclusion of the C-8-S-isomer in regulatory standards is reviewed. This review has identified that further research into the C-8-S-isomers of ergot alkaloids is warranted. In addition, the inclusion of the C-8-S-isomers into regulatory recommendations worldwide for food and feed should be implemented. The objectives of this review are to provide an overview of historic and current studies that have assessed the C-8-S-isomers. Specifically, this review will compare the C-8-R-isomers to the C-8-S-isomers with an emphasis on the biological activity and analytical assessment.

Rye Bran as a Component in the Diets of Lactating Sows-Effects on Sow and Piglet Performance

From a cost and sustainability perspective, the use of by-products such as rye bran in sow diets is of particular interest. Rye bran has valuable ingredients that have potential benefits for the gut health of sows. The aim of this study was to investigate the effects of including 15% rye bran in the sows' feed on the performance of sows and piglets. The feeding started one week before the farrowing date and ended at weaning. Performance was evaluated by measuring sow (n = 175) and piglet body weight (n = 1372) and sows' backfat thickness (n = 80). These data were additionally used to calculate the colostrum intake of the suckling piglets and the sows' milk production. It was found that there were no differences in the performance parameters between the experimental and control groups. However, this study showed that the piglets with light birth weight (LBW (<1000 g)) and medium birth weight (MBW (1000-1500 g) consumed more colostrum when the sows were fed rye bran (LBW: C/R 203.0 ± 39.2 g/214.3 ± 35.9 g; MBW: 291.3 ± 39.0 g/298.5 ± 36.4 g). It can be concluded that including 15% rye bran in the feed of lactating sows has no obvious negative effects on the performance of sows and piglets. Further studies are needed to evaluate the possible positive effects of rye bran.

Risks for animal health related to the presence of ergot alkaloids in feed

The European Commission requested EFSA to provide an update of the 2012 Scientific Opinion of the Panel on Contaminants in the Food Chain (CONTAM) on the risks for animal health related to the presence of ergot alkaloids (EAs) in feed. EAs are produced by several fungi of the Claviceps and Epichloë genera. This Opinion focussed on the 14 EAs produced by C. purpurea (ergocristine, ergotamine, ergocornine, α- and β-ergocryptine, ergometrine, ergosine and their corresponding 'inine' epimers). Effects observed with EAs from C. africana (mainly dihydroergosine) and Epichloë (ergovaline/-inine) were also evaluated. There is limited information on toxicokinetics in food and non-food producing animals. However, transfer from feed to food of animal origin is negligible. The major effects of EAs are related to vasoconstriction and are exaggerated during extreme temperatures. In addition, EAs cause a decrease in prolactin, resulting in a reduced milk production. Based on the sum of the EAs, the Panel considered the following as Reference Points (RPs) in complete feed for adverse animal health effects: for pigs and piglets 0.6 mg/kg, for chickens for fattening and hens 2.1 and 3.7 mg/kg, respectively, for ducks 0.2 mg/kg, bovines 0.1 mg/kg and sheep 0.3 mg/kg. A total of 19,023 analytical results on EAs (only from C. purpurea) in feed materials and compound feeds were available for the exposure assessment (1580 samples). Dietary exposure was assessed using two feeding scenarios (model diets and compound feeds). Risk characterisation was done for the animals for which an RP could be identified. The CONTAM Panel considers that, based on exposure from model diets, the presence of EAs in feed raises a health concern in piglets, pigs for fattening, sows and bovines, while for chickens for fattening, laying hens, ducks, ovines and caprines, the health concern related to EAs in feed is low.

Leucine-rich repeat kinase 2 promotes the development of experimental severe acute pancreatitis

Translocation of gut bacteria into the pancreas promotes the development of severe acute pancreatitis (SAP). Recent clinical studies have also highlighted the association between fungal infections and SAP. The sensing of gut bacteria by pattern recognition receptors promotes the development of SAP via the production of proinflammatory cytokines; however, the mechanism by which gut fungi mediate SAP remains largely unknown. Leucine-rich repeat kinase 2 (LRRK2) is a multifunctional protein that regulates innate immunity against fungi via Dectin-1 activation. Here, we investigated the role of LRRK2 in SAP development and observed that administration of LRRK2 inhibitors attenuated SAP development. The degree of SAP was greater in Lrrk2 transgenic (Tg) mice than in control mice and was accompanied by an increased production of nuclear factor-kappaB-dependent proinflammatory cytokines. Ablation of the fungal mycobiome by anti-fungal drugs inhibited SAP development in Lrrk2 Tg mice, whereas the degree of SAP was comparable in Lrrk2 Tg mice with or without gut sterilization by a broad range of antibiotics. Pancreatic mononuclear cells from Lrrk2 Tg mice produced large amounts of IL-6 and TNF-α upon stimulation with Dectin-1 ligands, and inhibition of the Dectin-1 pathway by a spleen tyrosine kinase inhibitor protected Lrrk2 Tg mice from SAP. These data indicate that LRRK2 activation is involved in the development of SAP through proinflammatory cytokine responses upon fungal exposure.

Response of growing pigs to the inclusion of hybrid rye in low or high-energy diets

Previous research has shown reduced feed intake and growth rate in pigs fed diets with hybrid rye replacing wheat. A reduction in growth rate caused by reduced feed intake will conceivably be counteracted by increasing the dietary energy level. Our objective, therefore, was to determine the effects of 40% hybrid rye inclusion replacing wheat in diets formulated to be either low or high net energy (NE) on growth, feed intake, energy digestibility, and lesion scores in growing-finishing pigs. We hypothesized that pigs fed 40% hybrid rye would perform better on the high than the low energy diets. A total of 160 pigs (body weight [BW] 70.1 kg) housed in 32 pens, 5 pigs per pen, were fed diets with 0% or 40% hybrid rye (var. 'KWS Bono'; KWS LOCHOW GMBH), either with low (2,350) or high (2,450) kcal NE per kg of diet over two growth phases (phase 1; 70 to 85 kg BW; phase 2; 85 to 130 kg BW). The BW, and feed disappearance were measured on days 0, 8, 17, 28, 42, and 50. Fecal samples obtained in phase 2 (~100 kg BW) were used to calculate apparent total tract digestibility (ATTD) of gross energy (GE). Lesion scores were measured weekly. The ATTD of GE was unaffected by rye inclusion and was reduced in low vs. high NE diets. Overall, (days 0 to 50), pigs fed the low-energy rye diet gained 0.08 kg/d less (P < 0.01) than those fed the high-energy rye diet or the low-energy diet without rye, which was caused by a reduced weight gain during the initial 17 d of the trial. Final BW and overall feed intake were not affected by rye inclusion or NE level. The NE intake was greater (P < 0.05) and feed efficiency (G:F) was reduced (P < 0.05) in pigs fed rye diets compared to those fed diets without rye, whereas there was no effect of NE level on NE intake or G:F. There was no effect of rye inclusion or NE level on lesion scores. In conclusion, pigs can be fed diets including 40% hybrid rye with only minor changes in growth performance. Increasing the NE level of the first phase diet in the grower-finisher barn may be useful to avoid a reduction in growth performance when feeding hybrid rye.

Occurrence of Ergot Alkaloids in Major and Minor Cereals from Northern Italy: A Three Harvesting Years Scenario

Ergot alkaloids (EAs), mycotoxins produced mainly by fungi of the Claviceps genus, have been frequently reported in rye, while their increasingly frequent occurrence in other cereals is likely related to weather conditions, with the incidence of ergot sclerotia in winter grains being related to heavy rainfall and moist soils at critical periods. However, compared to other regulated mycotoxins, data about the prevalence and occurrence of EAs in major and minor cereals harvested in the Mediterranean growing areas are still scant. In this regard, the current study reported the occurrence of EAs in 18 genotypes of winter cereals harvested over 3 years from an experimental field located in North Italy which were analyzed by HPLC-MS/MS. Results indicate a widespread occurrence of all the major EAs in all the considered cereal crops, especially under supportive meteorological conditions. EA contamination was dependent on the harvest year (p < 0.0001) which was particularly high in 2020 for all the considered species. The results also demonstrated a large co-occurrence of EAs with 98 cereal samples out of 162 contaminated with at least one of the 12 EAs (60% positive samples) in the range LOD: 15,389 μg/kg (median value: 2.32 μg/kg), expressed as the sum of the EAs. Rye was confirmed to be the crop more susceptible to the fungal infection (EAs content up to 4,302 μg/kg). To the best of our knowledge, we have reported the accumulation of EAs in tritordeum (LOD: 15,389 μg/kg) and in emmer (LOD: 1.9 μg/kg) for the first time.

The cultivation of rye in marginal Alpine environments: a comparison of the agronomic, technological, health and sanitary traits of local landraces and commercial cultivars

Rye is a secondary crop that is characterized by a higher tolerance to climatically less favorable conditions than other cereal species. For this reason, rye was historically used as a fundamental raw material for bread production and as a supply of straw in northern parts of Europe as well as in mountain environments, such as Alpine valleys, where locally adapted landraces have continued to be cultivated over the years. In this study, rye landraces collected in different valleys in the Northwest Italian Alps have been selected as the most genetically isolated within their geographical contexts and cultivated in two different marginal Alpine environments. The traits concerning their agronomy, mycotoxin contamination, bioactive content, as well as their technological and baking quality were assessed to characterize and compare rye landraces with commercial wheat and rye cultivars. Rye cultivars showed the same grain yield level as wheat in both environments. Only the genotype selected from the Maira Valley was characterized by tall and thin culms and a proneness to lodging, thereby resulting in a lower yield capacity. Among the rye cultivars, the hybrid one presented the highest yield potential, but also the highest susceptibility to the occurrence of ergot sclerotia. However, the rye cultivars, especially the landraces, were characterized by higher concentrations of minerals, soluble fibers, and soluble phenolic acids, and thus both their flours and breads had superior antioxidant properties. A 40% substitution of refined wheat flour with whole-grain rye flour led to a higher dough water absorption and a lower stability, thereby resulting in lower loaf volumes and darker products. Agronomically and qualitatively speaking, the rye landraces diverged significantly from the conventional rye cultivars, thus reflecting their genetic distinctiveness. The landrace from the Maira Valley shared a high content in phenolic acids and good antioxidant properties with the one from the Susa Valley and, when combined with wheat flour, turned out to be the most suitable for bread making. Overall, the results have highlighted the suitability of reintroducing historic rye supply chains, based on the cultivation of local landraces in marginal environments and the production of value-added bakery goods.

Effect of Field-applied Fungicides on Claviceps purpurea Sclerotia and Associated Toxins in Wheat

Claviceps purpurea (Fr.) Tul is the causal organism for ergot impacting grass hosts, including wheat. The pathogen produces ergot alkaloids (EAs) during the development of mature sclerotia leading to potential wheat quality discounts or rejection at the point of sale. Cultural practices are recommended for the management of ergot in wheat, but there is limited information pertaining to the use of in-season fungicides to help reduce ergot. The objective of this research was to evaluate the efficacy of four fungicides (prothioconazole + metconazole, pydiflumetofen + propiconazole, azoxystrobin + propiconazole, and fluxapyroxad + pyraclostrobin) on sclerotia characteristics, and EAs associated with C. purpurea. A field experiment was established using a male-sterile hard red spring line with fungicide applications occurring at complete full head emergence (Feekes Growth Stage 10.5). Individual plots were harvested and cleaned, and ergot sclerotia were collected. Physical characteristics and toxin production were examined. Fungicides had a significant (p < .05) impact on total ergot body weight (EBW), with all fungicides having lower EBW than the nontreated control. The fungicide premixture of pydiflumetofen + propiconazole had the lowest EBW among all treatments. Fluxapyroxad + pyraclostrobin had the lowest levels of EAs among fungicides. Results suggest that fungicide premixtures can potentially reduce EBW and influence EA production in wheat.

Winter rye cultivars moderately resistant to ergot

Background. Cereal ergot caused by the fungus Claviceps purpurea (Fr.) Tul. is a progressive disease of winter rye. There are no rye cultivars resistant to the disease, and breeding methods of protection have not been developed in Russia.

Materials and methods. The material for the research included 97 winter rye cultivars. A biochemical analysis of the sclerotia of the fungus was carried out, the composition and content of ergot alkaloids (EA) in the sclerotia of C. purpurea from the Kirov population were studied, and the relationship between the biometry of sclerotia and the EA content, toxicity and pathogenicity of C. purpurea was analyzed. Well-known methods of resistance assessment and EA analysis were applied.

Results and conclusions. Fourteen cultivars least affected by the pathogen were identified: ‘Flora’, ‘Kiprez’, ‘Grafinya’, ‘Lika’, ‘Batist’, ‘Simfoniya’, ‘Garmoniya’, ‘Sadko’, ‘Parom’, ‘Virazh’, ‘Saratovskaya 7’, ‘Volkhova’, ‘Novaya Era’, and ‘Podarok’. They can be used in breeding for ergot resistance. Three types of EA were identified in C. purpurea sclerotia: ergocristine, ergotamine, and its stereoisomer ergocristinine. Cvs. ‘Lika’, ‘Simfoniya’ and ‘Garmoniya’ were the least affected by ergot, and the sclerotia formed on the plants of these cultivars did not accumulate EA. A significant (r = 0.50–0.60) correlation was found between lesions and biometric parameters of C. purpurea sclerotia, and between grain contamination with sclerotia and their biometrics (r = 0.63– 0.78). A weak positive correlation (r = 0.22) was detected between the toxicity and pathogenicity of C. purpurea. A negative correlation was established between the weight of sclerotia and the accumulation of EA in them (r = –0.46), which indicated the biological danger of small sclerotia that got into the seed and food batches of grain. 

Influence of Planting Date and Cultivar on Diseases of Spring Durum Wheat

In the semiarid regions of North Dakota and Montana, low annual precipitation favors production of high-quality durum wheat (Triticum turgidum subsp. durum). However, conducive weather conditions for disease epidemics have occurred more frequently in recent years. Modification of planting date can reduce disease risk by decreasing the timeframe in which a susceptible crop overlaps with conducive disease conditions. The effect of planting date on fungal leaf spotting diseases (leaf spot), ergot, Fusarium head blight (FHB), and yield of durum was evaluated in 11 experiments across four sites in eastern Montana and western North Dakota. Six durum cultivars with differing levels of susceptibility to leaf spot and FHB were planted at three planting dates from 2017 to 2019. Early planting maximized yield and influenced ergot incidence. Although there was no effect of planting date, reduced susceptibility to leaf spot and FHB was associated with a reduction in leaf spotting disease severity and deoxynivalenol, respectively, in the harvested grain. Growers in the semiarid regions of these states should prioritize the selection of disease-resistant cultivars to help manage sporadic disease outbreaks and continue to plant early to maximize yield.

Improving Yield and Yield Stability in Winter Rye by Hybrid Breeding

Rye is the only cross-pollinating small-grain cereal. The unique reproduction biology results in an exceptional complexity concerning genetic improvement of rye by breeding. Rye is a close relative of wheat and has a strong adaptation potential that refers to its mating system, making this overlooked cereal readily adjustable to a changing environment. Rye breeding addresses the emerging challenges of food security associated with climate change. The systematic identification, management, and use of its valuable natural diversity became a feasible option in outbreeding rye only following the establishment of hybrid breeding late in the 20th century. In this article, we review the most recent technological advances to improve yield and yield stability in winter rye. Based on recently released reference genome sequences, SMART breeding approaches are described to counterbalance undesired linkage drag effects of major restorer genes on grain yield. We present the development of gibberellin-sensitive semidwarf hybrids as a novel plant breeding innovation based on an approach that is different from current methods of increasing productivity in rye and wheat. Breeding of new rye cultivars with improved performance and resilience is indispensable for a renaissance of this healthy minor cereal as a homogeneous commodity with cultural relevance in Europe that allows for comparatively smooth but substantial complementation of wheat with rye-based diets, supporting the necessary restoration of the balance between human action and nature.

Components of seed production and ergot resistance used as criteria for selection of Brachiaria hybrids

Ergot is a fungal disease and causes reductions in seed productivity and quality. We aimed to identify promising genotypes of brachiaria evaluating: (1) seed production potential (number of tillers, racemes per inflorescence, spikelets per raceme, raceme length, weight and number of seeds, and germination) and (2) resistance of seeds to Ergot (infected tillers, infected seeds). Five genotypes of Brachiaria grasses, four non-natural hybrids named BH1619, BH1810, BH1516 and Mavuno Palisadegrass (Urochloa brizantha x Urochloa ruziziensis), and Marandu Palisadegrass (U. brizantha Hoechst cv. Marandu) were evaluated. The BH1619 hybrid, despite the high weight of seeds, produced less viable, pure seeds. The hybrid BH1516 had a lower percentage of flowered tillers (42%) and seeds infected with ergot (8%). Marandu Palisadegrass had a higher percentage of infected tillers (95%) and infected seeds (38%). The hybrid BH1516 was the most resistant to ergot, followed by Mavuno Palisadegras sand BH1619. Among all materials, Mavuno Palisadegrass and BH1516 have a higher potential for seed production due to the higher percentage of flowered tillers and production of pure seeds with high germination capacity. The BH1516 hybrid was resistant to ergot, making it a better choice for use in infected areas used for seed or forage production.

Effects of particle size and phytase supplementation on apparent and standardized total tract digestibility of phosphorus in hybrid rye fed to growing pigs

An experiment was conducted to investigate the effects of particle size (PS) and levels of phytase supplementation on the apparent (ATTD) and standardized (STTD) total tract digestibility of P in hybrid rye fed to growing pigs. Thirty-six growing barrows (23.6 ± 1.5 kg initial BW) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six dietary treatments were arranged in a 2 × 3 factorial with main effects of PS and phytase supplementation levels (0, 500, or 2,500 FTU/kg). Hybrid rye was ground using a hammermill mounted with 4.0-mm and 3.2-mm screens to obtain material with coarse and fine PS, respectively. Pigs were fed experimental diets for 11 d, including 5 d for adaptation and 6 d for total collection of feces. All data were analyzed using the MIXED procedure of SAS with PS, phytase, and their interaction as fixed effects. Orthogonal polynomial contrasts were used to test linear and quadratic effects of phytase level in both coarse and fine hybrid rye diets. The ATTD and STTD of P were greater (P < 0.05) in diets with fine than in those with coarse hybrid rye. Increasing levels of phytase supplementation linearly (P < 0.01) and quadratically (P < 0.01) improved the ATTD and STTD of P in hybrid rye diets. There were no interaction effects between PS and phytase supplementation on the ATTD and STTD of P in hybrid rye diets. In conclusion, PS reduction improved the digestibility of P in hybrid rye, and supplementing increasing levels of phytase improved P digestibility in linear and quadratic manner in growing pigs fed hybrid rye diets.

Effective Pollen-Fertility Restoration Is the Basis of Hybrid Rye Production and Ergot Mitigation

Hybrid rye breeding leads to considerably higher grain yield and a higher revenue to the farmer. The basis of hybrid seed production is the CMS-inducing Pampa (P) cytoplasm derived from an Argentinean landrace and restorer-to-fertility (Rf) genes. European sources show an oligogenic inheritance, with major and minor Rf genes, and mostly result in low-to-moderate pollen-fertility levels. This results in higher susceptibility to ergot (Claviceps purpurea) because rye pollen and ergot spores are in strong competition for the unfertilized stigma. Rf genes from non-adapted Iranian primitive rye and old Argentinean cultivars proved to be most effective. The major Rf gene in these sources was localized on chromosome 4RL, which is also a hotspot of restoration in other Triticeae. Marker-based introgression into elite rye materials led to a yield penalty and taller progenies. The Rfp1 gene of IRAN IX was fine-mapped, and two linked genes of equal effects were detected. Commercial hybrids with this gene showed a similar low ergot infection when compared with population cultivars. The task of the future is to co-adapt these exotic Rfp genes to European elite gene pools by genomic-assisted breeding.

Prolonged absorption and susceptibility to enterohepatic circulation after oral administration of ergot alkaloids in ewes

The objective of this study was to evaluate the pharmacokinetics profile of ergot alkaloids when administered to sheep orally. Although ergot alkaloids frequently contaminate animal feed, current understanding of their pharmacokinetics in animals cannot adequately predict toxicity. Blood samples were collected from ewes at 0.5, 1, 3, 5, and 12 h after oral exposure to 4 ergot alkaloids: ergocornine, ergocristine, ergocryptine, and ergosine, followed by serum analysis of these alkaloids using high performance liquid chromatography and tandem mass spectrometry. The alkaloids showed extended absorption time, in addition to clear signs of enterohepatic circulation. This pharmacokinetic profile suggests potential enhanced toxicity in animals with disorders related to secretion of bile acid. It may also explain the high susceptibility of sheep to ergot poisoning compared to other species. An extended sampling protocol (> 12 h) is necessary, however, to identify the pharmacokinetic properties of ergot alkaloids in ewes. In conclusion, ewes exposed to ergot alkaloids showed a prolonged absorption phase and enterohepatic circulation, which is in contrast with human ergot pharmacokinetics.

Epichloë Endophyte-Promoted Seed Pathogen Increases Host Grass Resistance Against Insect Herbivory

Plants host taxonomically and functionally complex communities of microbes. However, ecological studies on plant-microbe interactions rarely address the role of multiple co-occurring plant-associated microbes. Here, we contend that plant-associated microbes interact with each other and can have joint consequences for higher trophic levels. In this study we recorded the occurrence of the plant seed pathogenic fungus Claviceps purpurea and aphids (Sitobion sp.) on an established field experiment with red fescue (Festuca rubra) plants symbiotic to a seed transmitted endophytic fungus Epichloë festucae (E+) or non-symbiotic (E-). Both fungi are known to produce animal-toxic alkaloids. The study was conducted in a semi-natural setting, where E+ and E- plants from different origins (Spain and Northern Finland) were planted in a randomized design in a fenced common garden at Kevo Subarctic Research Station in Northern Finland. The results reveal that 45% of E+ plants were infected with Claviceps compared to 31% of E- plants. Uninfected plants had 4.5 times more aphids than Claviceps infected plants. By contrast, aphid infestation was unaffected by Epichloë symbiosis. Claviceps alkaloid concentrations correlated with a decrease in aphid numbers, which indicates their insect deterring features. These results show that plant mutualistic fungi can increase the infection probability of a pathogenic fungus, which then becomes beneficial to the plant by controlling herbivorous insects. Our study highlights the complexity and context dependency of species-species and multi-trophic interactions, thus challenging the labeling of species as plant mutualists or pathogens.

Effects of Dietary Cereal and Protein Source on Fiber Digestibility, Composition, and Metabolic Activity of the Intestinal Microbiota in Weaner Piglets

Simple Summary

Rye and rapeseed meal can be alternative feed components for weaner piglets instead of wheat and soybean meal. Both components can help to meet current challenges in pig nutrition, such as increasingly dry weather conditions and the high amount of imported soybean. Since they contain more and differently composed fiber, effects on digestive physiology and intestinal microbiota might help to maintain gut health and prevent post-weaning diarrhea. This study shows that despite a similar composition of the large intestinal microbiota, the higher amount and solubility of complex carbohydrates from rye lead to a higher fermentative activity compared to wheat, which is considered a beneficial effect. The high amount of insoluble dietary fiber in rapeseed-based diets lowered bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria.

Abstract

This study aimed to investigate the effect of fiber-rich rye and rapeseed meal (RSM) compared to wheat and soybean meal (SBM) on fiber digestibility and the composition and metabolic activity of intestinal microbiota. At weaning, 88 piglets were allocated to four feeding groups: wheat/SBM, wheat/RSM, rye/SBM, and rye/RSM. Dietary inclusion level was 48% for rye and wheat, 25% for SBM, and 30% for RSM. Piglets were euthanized after 33 days for collection of digesta and feces. Samples were analyzed for dry matter and non-starch-polysaccharide (NSP) digestibility, bacterial metabolites, and relative abundance of microbiota. Rye-based diets had higher concentrations of soluble NSP than wheat-based diets. RSM-diets were higher in insoluble NSP compared to SBM. Rye-fed piglets showed a higher colonic and fecal digestibility of NSP (p < 0.001, p = 0.001, respectively). RSM-fed piglets showed a lower colonic and fecal digestibility of NSP than SBM-fed piglets (p < 0.001). Rye increased jejunal and colonic concentration of short-chain fatty acids (SCFA) compared to wheat (p < 0.001, p = 0.016, respectively). RSM-fed pigs showed a lower jejunal concentration of SCFA (p = 0.001) than SBM-fed pigs. Relative abundance of Firmicutes was higher (p = 0.039) and of Proteobacteria lower (p = 0.002) in rye-fed pigs compared to wheat. RSM reduced Firmicutes and increased Actinobacteria (jejunum, colon, feces: p < 0.050), jejunal Proteobacteria (p = 0.019) and colonic Bacteroidetes (p = 0.014). Despite a similar composition of the colonic microbiota, the higher amount and solubility of NSP from rye resulted in an increased fermentative activity compared to wheat. The high amount of insoluble dietary fiber in RSM-based diets reduced bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria. Further research should focus on host–microbiota interaction to improve feeding concepts with a targeted use of dietary fiber.

Discovery of a Novel Leaf Rust (Puccinia recondita) Resistance Gene in Rye (Secale cereale L.) Using Association Genomics

Leaf rust constitutes one of the most important foliar diseases in rye (Secale cereale L.). To discover new sources of resistance, we phenotyped 180 lines belonging to a less well-characterized Gülzow germplasm at three field trial locations in Denmark and Northern Germany in 2018 and 2019. We observed lines with high leaf rust resistance efficacy at all locations in both years. A genome-wide association study using 261,406 informative single-nucleotide polymorphisms revealed two genomic regions associated with resistance on chromosome arms 1RS and 7RS, respectively. The most resistance-associated marker on chromosome arm 1RS physically co-localized with molecular markers delimiting Pr3. In the reference genomes Lo7 and Weining, the genomic region associated with resistance on chromosome arm 7RS contained a large number of nucleotide-binding leucine-rich repeat (NLR) genes. Residing in close proximity to the most resistance-associated marker, we identified a cluster of NLRs exhibiting close protein sequence similarity with the wheat leaf rust Lr1 gene situated on chromosome arm 5DL in wheat, which is syntenic to chromosome arm 7RS in rye. Due to the close proximity to the most resistance-associated marker, our findings suggest that the considered leaf rust R gene, provisionally denoted Pr6, could be a Lr1 ortholog in rye.

Ergotism and Saint Anthony's fire

It has been widely accepted that ergot is a fungal disease caused by infection with the parasitic Claviceps purpurea leading to the development of typical black kernels n the plant. Ingestion of infected rye grains containing ergot alkaloids-usually in the form of contaminated rye bread-causes poisoning, also known as ergotism. The negative impacts of ergot contamination of grain on the health of humans and animals were first documented in ancient times. The history of ergotism shows the influence of food on human health. Although ergot has been known for ages, until the 18th century, its nature was not recognized. It was a part of the rye plant and it was used in traditional medicine. The diet was based was mostly on rye that led to neurologic disorders and gangrene. In the Middle Ages, in regions where rye was a dietary staple, many cases of a peculiar epidemic were recorded. Two names are usually used to describe it: "Saint Anthony's fire" and "holy fire," although there are many more appellations. The history of ergotism is a very important part of history of dermatology. The saint who people prayed to for protection against the disease was Anthony the Great (251-356). Monks of the Order of Saint Anthony played a particular role in treating ergotism by natural methods and specialized in treating skin diseases. Ergot alkaloids still pose a risk to human and animal safety if they appear in food.

Undertaking a New Regulatory Challenge: Monitoring of Ergot Alkaloids in Italian Food Commodities

The present manuscript reports on monitoring data of 12 ergot alkaloids (EAs) in cereal and cereal-derived products, collected in Italy over the period 2017-2020, for official control purposes under the edge of the Commission Recommendation 2012/154/EU on the monitoring of the presence of EAs in feed and food. To these purposes, an LC-MS/MS method was set up and applied, after in-house verification of its analytical performance. Besides satisfactory recoveries and precision, the method's quantification limits proved suitable to assess the compliance of cereals and cereal-based foods with the recently issued EU maximum permitted levels (Commission Regulation 2021/1399/EU). The validity of the generated data was also evaluated through the adoption of four proficiency tests, from which acceptable z-score values (-2 ≤ z ≤ 2) were obtained. The method was then applied to analyse a total of 67 samples, collected in Italy over the period 2017-2020. The samples consisted of 18 cereal grains, 16 flours (14 of wheat and 2 of spelt) and 31 other types of cereals derivatives (including 9 for infants). Overall, the EAs analysis returned a high percentage of left-censored data (>86%). Among the positive samples, the highest contamination levels, up to 94.2 µg/kg, were found for ergocristine (12% incidence), followed by ergocristinine (7% incidence) with levels of up to 48.3 µg/kg.

Evolution of the Ergot Alkaloid Biosynthetic Gene Cluster Results in Divergent Mycotoxin Profiles in Claviceps purpurea Sclerotia

Research into ergot alkaloid production in major cereal cash crops is crucial for furthering our understanding of the potential toxicological impacts of Claviceps purpurea upon Canadian agriculture and to ensure consumer safety. An untargeted metabolomics approach profiling extracts of C. purpurea sclerotia from four different grain crops separated the C. purpurea strains into two distinct metabolomic classes based on ergot alkaloid content. Variances in C. purpurea alkaloid profiles were correlated to genetic differences within the lpsA gene of the ergot alkaloid biosynthetic gene cluster from previously published genomes and from newly sequenced, long-read genome assemblies of Canadian strains. Based on gene cluster composition and unique polymorphisms, we hypothesize that the alkaloid content of C. purpurea sclerotia is currently undergoing adaptation. The patterns of lpsA gene diversity described in this small subset of Canadian strains provides a remarkable framework for understanding accelerated evolution of ergot alkaloid production in Claviceps purpurea.

High inclusion rates of hybrid rye instead of corn in diets for growing-finishing pigs do not influence the overall growth performance and most carcass traits are not influenced by hybrid rye

It was hypothesized that hybrid rye may replace corn in diets for growing and finishing pigs without impacting growth performance, carcass characteristics, or meat quality. A total of 128 pigs (23.69 ± 2.51 kg) were allotted to four treatments with eight replicate pens per treatment. Phases 1 and 2 diets were fed for 35 d each and phase 3 diets were fed for 27 d. Within each phase, pigs were fed a control corn and soybean meal diet or a diet in which 33%, 66%, or 100% of the corn in the control diet was replaced with hybrid rye. Average daily gain (ADG) and average daily feed intake (ADFI) decreased (linear, P < 0.05) in phase 1 with increased dietary inclusion of hybrid rye. In phase 3, gain:feed (G:F) increased and then decreased (quadratic, P < 0.05) with more hybrid rye in the diet. Overall ADG, ADFI, and G:F did not differ among treatments. Diet did not impact most carcass traits, but loin (visual) and backfat (instrumental L*) color were paler (linear, P < 0.05) with greater inclusion of hybrid rye in the diet. Organ weights increased (linear, P < 0.05) with increased dietary hybrid rye. In conclusion, pigs fed hybrid rye consumed less feed in phase 1, resulting in reduced ADG, but growth performance for the entire growing-finishing period did not differ among treatments. Hybrid rye may replace all the corn in growing and finishing pig diets without diminishing growth performance or carcass quality, but feed intake may be reduced at high inclusion rates.

Structural and nutritional portrayal of rye-supplemented bread using fourier transform infrared spectroscopy and scanning electron microscopy

In the present study, four different variants, namely Gp-1, Gp-2, Gp-3, and Gp-4, were characterized for their nutritional and fatty acid profile. Later on, the nutritionally superior variant was used for bread preparation. Purposely, composite flour was prepared with different ratios of wheat and rye (100:0; 90:10; 80:20). Furthermore, structural characterization of bread was done using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Results showed that the Gp-2 was more nutritional among the four variants. Furthermore, the spectra of composite flour bread were scanned in the range of 4000-600 cm-1. All the bread samples presented almost similar spectra for major peaks corresponding to wavenumbers in the functional group. The SEM micrographs showed the presence of small and large starch particles with compact structures. Conclusively, rye flour supplementation has a significant impact on the nutritional and structural attributes of the bread.

Genome-wide analysis of Claviceps paspali: insights into the secretome of the main species causing ergot disease in Paspalum spp

BACKGROUND

The phytopatogen Claviceps paspali is the causal agent of Ergot disease in Paspalum spp., which includes highly productive forage grasses such as P. dilatatum. This disease impacts dairy and beef production by affecting seed quality and producing mycotoxins that can affect performance in feeding animals. The molecular basis of pathogenicity of C. paspali remains unknown, which makes it more difficult to find solutions for this problem. Secreted proteins are related to fungi virulence and can manipulate plant immunity acting on different subcellular localizations. Therefore, identifying and characterizing secreted proteins in phytopathogenic fungi will provide a better understanding of how they overcome host defense and cause disease. The aim of this work is to analyze the whole genome sequences of three C. paspali isolates to obtain a comparative genome characterization based on possible secreted proteins and pathogenicity factors present in their genome. In planta RNA-seq analysis at an early stage of the interaction of C. paspali with P. dilatatum stigmas was also conducted in order to determine possible secreted proteins expressed in the infection process.

RESULTS

C. paspali isolates had compact genomes and secretome which accounted for 4.6-4.9% of the predicted proteomes. More than 50% of the predicted secretome had no homology to known proteins. RNA-Seq revealed that three protein-coding genes predicted as secreted have mayor expression changes during 1 dpi vs 4 dpi. Also, three of the first 10 highly expressed genes in both time points were predicted as effector-like. CAZyme-like proteins were found in the predicted secretome and the most abundant family could be associated to pectine degradation. Based on this, pectine could be a main component affected by the cell wall degrading enzymes of C. paspali.

CONCLUSIONS

Based on predictions from DNA sequence and RNA-seq, unique probable secreted proteins and probable pathogenicity factors were identified in C. paspali isolates. This information opens new avenues in the study of the biology of this fungus and how it modulates the interaction with its host. Knowledge of the diversity of the secretome and putative pathogenicity genes should facilitate future research in disease management of Claviceps spp.

Key Global Actions for Mycotoxin Management in Wheat and Other Small Grains

Mycotoxins in small grains are a significant and long-standing problem. These contaminants may be produced by members of several fungal genera, including Alternaria, Aspergillus, Fusarium, Claviceps, and Penicillium. Interventions that limit contamination can be made both pre-harvest and post-harvest. Many problems and strategies to control them and the toxins they produce are similar regardless of the location at which they are employed, while others are more common in some areas than in others. Increased knowledge of host-plant resistance, better agronomic methods, improved fungicide management, and better storage strategies all have application on a global basis. We summarize the major pre- and post-harvest control strategies currently in use. In the area of pre-harvest, these include resistant host lines, fungicides and their application guided by epidemiological models, and multiple cultural practices. In the area of post-harvest, drying, storage, cleaning and sorting, and some end-product processes were the most important at the global level. We also employed the Nominal Group discussion technique to identify and prioritize potential steps forward and to reduce problems associated with human and animal consumption of these grains. Identifying existing and potentially novel mechanisms to effectively manage mycotoxin problems in these grains is essential to ensure the safety of humans and domesticated animals that consume these grains.

Effects of ergotamine on the central nervous system using untargeted metabolomics analysis in a mouse model

The ergot alkaloid ergotamine is produced by Claviceps purpurea, a parasitic fungus that commonly infects crops and pastures of high agricultural and economic importance. In humans and livestock, symptoms of ergotism include necrosis and gangrene, high blood pressure, heart rate, thermoregulatory dysfunction and hallucinations. However, ergotamine is also used in pharmaceutical applications to treat migraines and stop post-partum hemorrhage. To define its effects, metabolomic profiling of the brain was undertaken to determine pathways perturbed by ergotamine treatment. Metabolomic profiling identified the brainstem and cerebral cortex as regions with greatest variation. In the brainstem, dysregulation of the neurotransmitter epinephrine, and the psychoactive compound 2-arachidonylglycerol was identified. In the cerebral cortex, energy related metabolites isobutyryl-L-carnitine and S-3-oxodecanoyl cysteamine were affected and concentrations of adenylosuccinate, a metabolite associated with mental retardation, were higher. This study demonstrates, for the first time, key metabolomic pathways involved in the behavioural and physiological dysfunction of ergot alkaloid intoxicated animals.

Hybrid rye may replace up to 75% of the corn in diets for gestating and lactating sows without negatively impacting sow and piglet performance

An experiment was conducted to test the hypothesis that hybrid rye can replace a part of the corn in gestation and lactation diets without negatively affecting sow and litter performance. For each phase, a corn-soybean meal diet and three diets in which hybrid rye replaced 25%, 50%, or 75% of corn were formulated. Two hundred sows were randomly allotted by parity to the four treatments. Results indicated that diet did not affect body weight or average daily gain (ADG) of sows or number of pigs born. The number of pigs weaned, litter weaning weight, and litter ADG increased and then decreased (quadratic, P < 0.05) as hybrid rye in diets increased. Pig mortality and number of crushed pigs tended (quadratic, P < 0.10) to be reduced as hybrid rye was added to the diet. Serum cytokines did not differ among treatments on day 105 of gestation or in pigs on the day of weaning, but interleukin (IL)-4, IL-10, and IL-18 on day 13 of lactation increased and then decreased (quadratic, P < 0.05) as hybrid rye inclusion increased in diets. Milk urea N increased (linear, P < 0.05) as hybrid rye was included in the diet, but no other differences in milk composition were observed. Overall, replacing 25% or 50% of corn with hybrid rye resulted in improved lactation performance, and replacing 75% of corn with hybrid rye resulted in sow and litter performance that was not different from that of sows fed control diets.

Effects of cereal and protein source on performance, apparent ileal protein digestibility and intestinal characteristics in weaner piglets

Rye and rapeseed meal (RSM) are alternatives to wheat and soybean meal (SBM) in pig nutrition. The inclusion of rye and RSM instead of wheat and SBM may increase dietary fibre content in the feed, which may affect digestive physiology and intestinal function. However, research on the combined feeding of rye and RSM in piglets is still scarce. The aim of this study was to investigate the effects of rye and RSM containing feed on growth performance, protein and amino acid digestibility, physical characteristics of the digesta and the intestinal morphology in weaner piglets. A total of 88 piglets aged 28 d were randomly allotted to four different feeding groups at weaning: wheat/SBM, wheat/RSM, rye/SBM, rye/RSM. Cereals were included at 48%, SBM at 25% and RSM at 30%. Body weight gain and feed intake were recorded weekly. After 33 d, piglets were euthanised for assessment of digesta and intestinal morphology. Rye did not affect performance, whilst RSM resulted in reduced weight gain (p = 0.024) and feed intake (p = 0.037). Apparent ileal digestibility of crude protein and amino acids was decreased by rye and RSM (p < 0.05). Rye caused an acidification (p = 0.045) and increased viscosity (p = 0.013) of small intestinal digesta, a lower dry matter content of jejunal and colonic digesta (p < 0.05) and an increased relative weight of the colon tissue (p < 0.001). In conclusion, performance was not reduced when rye was used as an alternative to wheat in diets for weaner piglets. The inclusion of RSM instead of SBM to piglets' diet lowered animal performance under our conditions. Further investigations are warranted to characterise the quality of rapeseed meal and the optimum inclusion level in the diet for young pigs.

Effect of Rye Grain Derived from Different Cultivars or Maize Grain Use in the Diet on Ruminal Fermentation Parameters and Nutrient Digestibility in Sheep

Six wether sheep with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square to determine the effect of rye grain (from an open-pollinated or a hybrid cultivar) and maize grain from hybrid cultivar inclusion in the diet on ruminal fermentation parameters and nutrient digestion in different gastrointestinal tract compartments. The experimental diets consisted of meadow hay (800 g/day) and a concentrate mixture (300 g/day) that contained rye grain from an openpollinated cultivar (OPRG), rye grain from a hybrid cultivar (HRG), or maize grain from a hybrid cultivar (MG) as a main energy source. Each experimental period lasted 17 days and consisted of 10 days for diet adaptation and 7 days for data and sample collection. Ruminal fermentation (pH, short-chain fatty acids, and ammonia concentration) and nutrient digestion up to the duodenum (in reticulorumen, omasum, and abomasum), in the intestine, as well as in the total digestive tract was investigated. Mean ruminal pH was higher for MG compared to HRG and OPRG (P<0.01) but did not differ between HRG and OPRG (6.45, 6.35, and 6.29 for MG, HRG, and OPRG, respectively). Treatment did not affect short-chain fatty acid concentration in the rumen, except for the molar proportions of valeric acid and of isovaleric acid of the total short-chain fatty acids, which was or tended to be higher (P≤0.06) for MG compared to HRG and OPRG. Less starch was digested in the gastrointestinal tract up to the duodenum and more in the intestine for MG compared to HRG and OPRG (P=0.01); however, total tract nutrient digestibility did not differ between treatments. In conclusion, usage of rye grain in sheep diets resulted in a lower ruminal pH compared to maize grain usage. No differences for ruminal fermentation, nutrient digestion up to the duodenum, in the intestine, as well as in the total digestive tract between rye grain from open-pollinated and hybrid cultivar usage in sheep diets were found.

Gravimetric quantitative validation of botanic impurities in feed

BACKGROUND

Harmful botanical impurities may contaminate feed and feed materials and be a potential danger to animal or human health, or to the environment. The aim of this study was to establish rapid and sensitive methods that can be used in routine official controls to determine botanical impurities such as Datura stramonium, Ricinus communis, Crotaliaria spp., and Ambrosia spp. in animal feed and raw materials. Claviceps sclerotia were also detected in cereals, due to the similarities of the targets and the analytical procedure. Regulation (EU) 625/2017, which replaces Reg. 2004/882/EC, states that EU member states should conduct official controls in assessed and accredited laboratories and that the analytical methods must be validated before use by considering parameters such as specificity, precision, recovery, and measurement uncertainly.

RESULTS AND CONCLUSION

The results demonstrate that all of the methods tested are suitable for the official quantitative analyses required by EU official legislation. © 2020 Society of Chemical Industry.

Genetic mapping of pollen fertility restoration QTLs in rye (Secale cereale L.) with CMS Pampa

Cytoplasmic male sterility (CMS) is a widely applied plant breeding tool for hybrid seed production. The phenomenon is often caused by chimeric genes with altered open reading frames (ORFs) located in the mitochondrial genomes and expressed as novel genotoxic products that induce pollen abortion. The fertility of CMS plants can be restored by nuclear-encoded genes that inhibit the action of ORFs responsible for pollen sterility. A recombinant inbred line (RIL) mapping population S64/04/01, encompassing 175 individuals, was used for genetic map construction and identification of quantitative trait loci (QTLs) responsible for fertility restoration in rye (Secale cereale L.) with CMS Pampa. The genetic map of all seven rye chromosomes included 15,516 SNP and silicoDArT markers and covered 1070.5 cm. Individual QTLs explaining 60% and 5.5% of the fertility trait’s phenotypic variance were mapped to chromosomes 4R (QRft-4R) and 5R (QRft-5R), respectively. Association mapping identified markers with the highest R² value of 0.58 (p value = 2.21E-28). Markers showing the highest associations with the trait were also mapped to the 4R chromosome within the QRft-4R region. Based on marker sequence homology, putative genes involved in pollen fertility restoration were suggested. Five silicoDArTs were converted into PCR-based markers for further breeding purposes.

Problems of phytoimmunity of grain crops in the Euro-Northeast of the Russian Federation and ways their solution

Breeding of grain crops for phytoimmunity in the FSBSU FASC of the Northeast is carried out in the conditions of natural and artificial epiphytotics. Every year, more than 1000 samples of winter rye, spring soft wheat, barley and oats of their own breeding and from the VIR collection are studied. In winter rye, studies are conducted on snow mold, root rot, powdery mildew, brown and stem rust, septoria blight, fusarium head blight, and ergot; in spring wheat – on root rot, septoria blight, fusarium head blight, powdery mildew, brown rust, loose smut; in barley – on root rot, net, dark brown blotch and stripe disease, loose smut; in oats - on red-brown blotch, root rot, crown rust, panicle fusarium and loose smut. Resistant samples detected on infectious backgrounds will be included in the breeding process as sources of the trait. With the participation of source genes, new varieties of winter rye were created, Snezhana, Grefinya, and others, which are being studied at different breeding stages. Long-term studies (2014-2020) on infectious and provocative backgrounds among the breeding material of the FASC of the Northeast and collection samples of spring soft wheat, oats, barley revealed sources of nonspecific resistance (6-9 points). They are used in crossbreeding programs with the best varieties to obtain high-yielding and resistant to biotic stressors hybrids that are being studied at different breeding stages.

Ergot and Ergot Alkaloids in Cereal Grains Intended for Animal Feeding Collected in Slovenia: Occurrence, Pattern and Correlations

This four-year study reports the occurrence of ergot alkaloids (EAs) in cereals intended for animal feeding collected in Slovenia. A total of 517 samples of cereals were analysed using liquid chromatography-tandem mass spectrometry for the presence of EAs. The sample set included wheat, rye, triticale, oat, spelt and barley. The study revealed that 17% of the analysed cereal samples were contaminated with at least one ergot alkaloid. EAs have two epimeric forms: -ine and -inine. The incidence rates of the -ine and -inine forms in the analysed samples were 16% and 15%, respectively. The highest contamination rates were observed in rye (54%), oat (50%) and spelt (30%), where the highest mean concentrations of total EAs were also determined (502 µg/kg, 594 µg/kg and 715 µg/kg, respectively). However, the highest concentrations of total EAs were found in wheat and rye (4217 µg/kg and 4114 µg/kg, respectively). The predominant EAs were ergometrine, ergosine and ergocristinine. The occurrence of six or more ergot alkaloids was observed in 49% of the positive samples. A weak correlation (p = 0.284) in the positive samples was found between the mass of sclerotia and the total concentrations of EAs using the Spearman correlation coefficient.

Covariation of Ergot Severity and Alkaloid Content Measured by HPLC and One ELISA Method in Inoculated Winter Rye across Three Isolates and Three European Countries

Ergot caused by Claviceps purpurea is a problem for food and feed security in rye due to the occurrence of toxic ergot alkaloids (EAs). For grain elevators and breeders, a quick, easy-to-handle, and cheap screening assay would have a high economic impact. The study was performed to reveal (1) the covariation of ergot severity (= percentage of sclerotia in harvested grain) and the content of 12 EAs determined by high performance liquid chromatography (HPLC) and (2) the covariation between these traits and results of one commercial enzyme linked immunosorbent assays (ELISA). In total, 372 winter rye samples consisting of a diverse set of genotypes, locations from Germany, Austria, and Poland over two years, and three isolates were analyzed. Ergocornine and α-ergocryptine were detected as major EAs. Ergocristinine occurred as a minor component. Claviceps isolates from different countries showed a similar EA spectrum, but different quantities of individual EAs. A moderate, positive covariation between ergot severity and EA content determined by HPLC was observed across two years (r = 0.53, p < 0.01), but large deviation from the regression was detected. ELISA values did neither correlate with the HPLC results nor with ergot severity. In conclusion, a reliable prediction of the EA content based on ergot severity is, at present, not possible.

Effect of a High Proportion of Rye in Compound Feed for Reduction of Salmonella Typhimurium in Experimentally Infected Young Pigs

Public health concerns and the potential for food-borne zoonotic transmission have made Salmonella a subject of surveillance programs in food-producing animals. Forty-two piglets (25 d of age and initially 7.48 kg) were used in a 28 d infection period to evaluate the effects of a high proportion of rye on reducing Salmonella Typhimurium. Piglets were divided into two diet groups: control diet (wheat 69%) and experimental diet (rye 69%). After a one-week adaptation period, all piglets were orally infected with Salmonella Typhimurium (10⁷ log CFU/mL; 2mL/pig). Salmonella in fecal shedding were evaluated at day 1, 3, 5, 7 and then weekly after infection. At the end of the experimental period (at day 28 after infection), the piglets were euthanized to sample feces, cecal digesta contents and ileocecal lymph nodes to determine the bacterial counts of Salmonella. The results suggest that the bacterial counts in the experimental group fed rye diets showed evidence of reducing Salmonella fecal shedding from day 14 onwards and decreasing the number of Salmonella in cecal digesta. However, the translocation of Salmonella in ileocecal lymph nodes was not affected. Furthermore, feed intake, weight gain and feed conversion did not differ between the groups (p > 0.05).

De novo transcriptome assembly, functional annotation, and expression profiling of rye (Secale cereale L.) hybrids inoculated with ergot (Claviceps purpurea)

Rye is used as food, feed, and for bioenergy production and remain an essential grain crop for cool temperate zones in marginal soils. Ergot is known to cause severe problems in cross-pollinated rye by contamination of harvested grains. The molecular response of the underlying mechanisms of this disease is still poorly understood due to the complex infection pattern. RNA sequencing can provide astonishing details about the transcriptional landscape, hence we employed a transcriptomic approach to identify genes in the underlying mechanism of ergot infection in rye. In this study, we generated de novo assemblies from twelve biological samples of two rye hybrids with identified contrasting phenotypic responses to ergot infection. The final transcriptome of ergot susceptible (DH372) and moderately ergot resistant (Helltop) hybrids contain 208,690 and 192,116 contigs, respectively. By applying the BUSCO pipeline, we confirmed that these transcriptome assemblies contain more than 90% of gene representation of the available orthologue groups at Virdiplantae odb10. We employed a de novo assembled and the draft reference genome of rye to count the differentially expressed genes (DEGs) between the two hybrids with and without inoculation. The gene expression comparisons revealed that 228 genes were linked to ergot infection in both hybrids. The genome ontology enrichment analysis of DEGs associated them with metabolic processes, hydrolase activity, pectinesterase activity, cell wall modification, pollen development and pollen wall assembly. In addition, gene set enrichment analysis of DEGs linked them to cell wall modification and pectinesterase activity. These results suggest that a combination of different pathways, particularly cell wall modification and pectinesterase activity contribute to the underlying mechanism that might lead to resistance against ergot in rye. Our results may pave the way to select genetic material to improve resistance against ergot through better understanding of the mechanism of ergot infection at molecular level. Furthermore, the sequence data and de novo assemblies are valuable as scientific resources for future studies in rye.

Comparative Ergot Alkaloid Elaboration by Selected Plectenchymatic Mycelia of Claviceps purpurea through Sequential Cycles of Axenic Culture and Plant Parasitism

Ergot alkaloids have an established place in plant pathology and toxicology. As pharmaceuticals, their sourcing is via natural or managed agricultural occurrence of sclerotia of Claviceps purpurea (Fr.) Tul. or through industrial fermentation processes with other Claviceps. The key factor for biosynthesis is differentiation of a particular mycelial anatomy. Previous study of these fungi from two disparate English grass genera, Spartina and Phragmites, has shown that only mycelia expressing a plectenchymatic sclerotium-like anatomy in specific axenic culture conditions elaborated ergot alkaloids, and then only as far as lysergic acid. The present report describes sequential cycles of axenic and parasitic cultivation for wild isolates from Dactylis and Alopecurus with intervention of a single ascospore step. This confirms the homozygous character of C. purpurea and defines several potential experimental axenic and parasitic conditions within the species for comparing genomic aspects of partial or full biosynthesis of cyclic tri-peptide alkaloids. Whereas Alopecurus ergot isolates readily parasitized rye, use of Dactylis isolates as inoculum for rye ovaries failed to cause the usual sphacelial fructification but supported growth of exceptionally thin sclerotia, sometimes two in a floret, with low alkaloid content attributed to reduced medullary component. However, after two cycles of axenic and rye-parasitic cultivation, and consistent re-selection of the plectenchymatic character in axenic mycelia, typical growth of ergot sclerotia occurred on rye. Caution thus seems necessary in tests for putative host specificity in any taxonomic realignments within the classical concept of C. purpurea. A Dactylis ergot isolate was also uniquely shown to parasitise the plumule of germinating rye seeds confirming the susceptibility of apical tissues. A key biosynthetic feature of a mycelial glyceride oil, rich in ricinoleic acid, as a prelude to axenic and parasitic formation of ergot alkaloids by C. purpurea is emphasised.

Diversity of Claviceps paspali reveals unknown lineages and unique alkaloid genotypes

Claviceps species affecting Paspalum spp. are a serious problem, as they infect forage grasses such as Paspalum dilatatum and P. plicatulum, producing the ergot disease. The ascomycete C. paspali is known to be the pathogen responsible for this disease in both grasses. This fungus produces alkaloids, including ergot alkaloids and indole-diterpenes, that have potent neurotropic activities in mammals. A total of 32 isolates from Uruguay were obtained from infected P. dilatatum and P. plicatulum. Isolates were phylogenetically identified using partial sequences of the genes coding for the second largest subunit of RNA polymerase subunit II (RPB2), translation elongation factor 1-α (TEF1), β-tubulin (TUB2), and the nuc rDNA 28S subunit (28S). Isolates were also genotyped by randomly amplified polymorphic DNA (RAPD) and presence of genes within the ergot alkaloid (EAS) and indole-diterpene (IDT) biosynthetic gene clusters. This study represents the first genetic characterization of several isolates of C. paspali. The results from this study provide insight into the genetic and genotypic diversity of Claviceps paspali present in P. dilatatum and suggest that isolates from P. plicatulum could be considered an ecological subspecies or specialized variant of C. paspali. Some of these isolates show hypothetical alkaloid genotypes never reported before.

Increasing hybrid rye level substituting wheat grain with or without enzyme on growth performance and carcass traits of growing-finishing barrows and gilts

New European, fall-planted hybrid rye grown in western Canada is more resistant to ergot and fusarium and has lower content of anti-nutritional factors than common rye. We evaluated the effect of feeding increasing hybrid rye level substituting wheat grain and non-starch polysaccharide (NSP) enzyme inclusion in diets fed to growing-finishing pigs raised under western Canadian commercial conditions. In total, 1,008 pigs (~44 kg body weight [BW]) housed in 48 pens by sex, 21 pigs per pen, were fed diets with one of three rye (var. KWS Bono; KWS LOCHOW GMBH) inclusion levels substituting wheat grain: low (L; one-third of wheat replaced), medium (M; two-thirds of wheat replaced), or high (H; most wheat replaced), either without (WO) or with (W) enzyme inclusion (280 units of β-glucanase and 900 units of xylanase per kilogram feed; Endofeed W DC; GNC Bioferm) over four growth phases (Grower 2: d 0 to 22, Grower 3: d 23 to 42, Finisher 1: d 43 to 63, Finisher 2: d 64 to slaughter). Pen BW, feed added, and orts were measured on d 0, 22, 42, 63, 76, 91, and at slaughter weight (130 kg). Warm carcasses were weighed and graded (Destron). BW was not affected by either increasing hybrid rye level substituting wheat grain or enzyme inclusion throughout the trial. For the entire trial (d 0 to 76), pigs fed increasing hybrid rye level substituting wheat grain had decreased (P < 0.050) average daily feed intake (ADFI; L 3.05, M 2.98, H 2.91 kg/d) and average daily weight gain (ADG; L 1.01, M 1.00, H 0.97 kg/d). Enzyme inclusion did not affect ADFI but tended (P = 0.080) to increase ADG (WO 0.98, W 1.00 kg/d). Enzyme inclusion improved (P < 0.050) gain-to-feed ratio only in pigs fed the H rye level. Most carcass traits were not affected by either increasing hybrid rye level substituting wheat grain or enzyme inclusion. Increasing dietary hybrid rye level substituting wheat grain increased (P < 0.001) cost per tonne of feed (L 240.28, M 241.28, H 242.20 Can$/kg), but did not affect feed cost per pig or per kilogram BW gain. Enzyme inclusion increased (P < 0.001) cost per tonne of feed (WO 240.36, W 242.15 Can$/kg), but feed cost per pig (WO 82.14, W 80.44 Can$ per pig) and per kilogram BW gain (WO 0.96, W 0.94 Can$/kg gain) were reduced (P < 0.050). In conclusion, fall-planted hybrid rye can completely replace wheat grain in grower-finisher pig diets without affecting feed efficiency, feed cost per pig or feed cost per kilogram BW gain. Inclusion of NSP enzyme would be recommended for diets including high rye levels to improve feed efficiency and ADG.

Effects of microbial phytase on standardized total tract digestibility of phosphorus in hybrid rye, barley, wheat, corn, and sorghum fed to growing pigs

An experiment was conducted to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P in three varieties of hybrid rye and in one source of barley, wheat, corn, and sorghum. The STTD of P in each cereal grain was determined both without and with addition of microbial phytase. In total, 112 growing barrows (13.7 ± 1.3 kg initial BW) were allotted to a randomized complete block design with four blocks of 28 pigs. Pigs were randomly allotted to 14 diets with two replicate pigs per diet in each block, resulting in a total of eight replicate pigs per diet for the four blocks. Each diet contained one of the cereal grains as the sole source of P. There were two diets with each cereal grain with one diet containing no microbial phytase and the other diet containing 1,000 units of microbial phytase per kilogram of diet. In each period, fecal output was collected for 5 d following a 5-d adaptation period according to the marker-to-marker procedure. Among the diets that did not include microbial phytase, one hybrid of rye had greater (P < 0.05) STTD of P than wheat, corn, and sorghum, which is likely a result of the greater intrinsic phytase activity in rye than in the other cereal grains. Without microbial phytase, there was no difference in the STTD of P in the three hybrids of rye and barley. Among the diets containing microbial phytase, there was no difference in STTD of P among the three hybrids of rye, barley, and corn. The STTD of P in the three hybrids of rye with microbial phytase was 61.9%, 70.8%, and 63.0%, respectively. Overall, microbial phytase improved (P < 0.05) the STTD of P in all cereal grains, although the magnitude of the increase in STTD of P differed among the grains.

Apparent and standardized ileal digestibility of AA and starch in hybrid rye, barley, wheat, and corn fed to growing pigs

An experiment was conducted to determine the apparent ileal digestibility (AID) of AA and starch and the standardized ileal digestibility (SID) of AA in three varieties of hybrid rye and in one source of barley, wheat, and corn. Seven growing barrows (initial BW = 26.1 ± 2.4 kg) were randomly allotted to a 7 × 7 Latin square design with seven periods and seven experimental diets. Six diets included one of the grains as the sole source of AA, and an N-free diet was used to determine basal endogenous losses of CP and AA. In each period, ileal digesta were collected for 8 h on days 6 and 7 following a 5-d adaptation period. At the conclusion of the experiment, all ingredients, diets, and ileal digesta samples were analyzed for starch, CP, and AA. The AID of starch was greater (P < 0.05) in wheat and corn than in barley or hybrid rye, but all grains had AID values for starch that were above 95%. Wheat and barley contained more CP and indispensable AA than hybrid rye, but hybrid rye contained more indispensable AA compared with corn. The SID of CP and all indispensable AA was greater (P < 0.05) in barley, wheat, and corn than in the three varieties of rye. However, because of the greater concentration of AA in hybrid rye than in corn, the quantities of standardized ileal digestible CP and AA were not different between corn and hybrid rye. In conclusion, hybrid rye has greater concentrations of most AA than corn, but the digestibility of AA in rye is less than in other cereal grains. It is likely that the reason for the reduced SID of AA in rye is that rye contains more fructans and soluble dietary fiber than other cereal grains, which may increase viscosity and reduce the efficiency of endogenous peptidases.

Occurrence of ergot and its alkaloids in winter rye harvested in Poland

Ergot (Claviceps purpurea) is a fungal pathogen that infects various grass and small grain cereal species, most often open-pollinated grasses, including rye and triticale. We tested 122 samples of rye grains harvested in three different regions of Poland in 2016 and 2017 for ergot and its alkaloids. Ergot sclerotia were found in all samples. The mean content of ergot sclerotia in grain ranged between 0.74 and 1.06 g/kg, and the mean concentration of ergot alkaloids in grain ranged between 270.1 and 580. 4 μg/kg, depending on the region of cultivation. 37% of the samples were infected with ergot below the 0.5 g/kg level set by the European Commission as the maximum permissible level for ergot, and in those samples the mean ergot alkaloids concentration was 155.8 μg/kg (range 4.7-667.9 μg/kg). A statistically significant correlation (R2=0.6941) between ergot content and concentration of ergot alkaloids was found. Ergot alkaloids concentration in grain was re-calculated into ergot alkaloids concentration in sclerotia, and was found to vary widely from 114 to 3,167 mg/kg. Ergot alkaloids profiles were most frequently dominated by R-configured ergopeptides, such as ergocryptine, ergocornine and ergocristine (31, 29 and 16% of the samples, respectively).

Arterial Responses to Acute Low-Level Ergot Exposure in Hereford Cows

Ergot alkaloids are toxic secondary metabolites produced by the fungus Claviceps purpurea that contaminate cereal grains. Current Canadian standards allow 2 to 3 parts per million of ergot alkaloids in animal feed. The purpose of this study was to determine whether hemodynamic parameters were altered when beef cows were fed permissible levels of ergot alkaloids (i.e., <3 ppm) on a short-term basis. A dose-response relationship between ergot alkaloid concentration and hemodynamic changes in caudal (coccygeal), median sacral, and internal iliac arteries was hypothesized. Beef cows were randomly allocated to: Control (<15 μg total ergot alkaloids/kg dry matter), Low (132 μg/kg), Medium (529 μg/kg), and High (2115 μg/kg) groups (n = 4 per group). Animals were fed 8.8 kg of dry matter daily for 4 days (pre-treatment), 7 days (treatment), and 4 days (post-treatment). The caudal, median sacral, and internal iliac arteries were examined daily using ultrasonography in B-mode and Doppler (color and spectral) mode and hemodynamics endpoints were analyzed by repeated measures mixed model analyses. Caudal artery diameter decreased in the Medium (p = 0.004) and High (p < 0.001) groups compared to pre-treatment values and the pulsatility index increased (p ≤ 0.033) in all ergot treatments during the post-exposure period compared to the Control group. Blood volume per pulse (mL) and blood flow (mL/min) through the caudal artery during the treatment period were reduced in the Medium (-1.0 mL reduction; p ≤ 0.004) and High (-1.1 mL p ≤ 0.006) groups compared to pre-treatment values. The median sacral artery diameter decreased in the Medium (p = 0.006) and High (p = 0.017) treatments compared to the Control group. No differences were detected in any hemodynamic endpoints for the internal iliac artery except changes in pulse rate (p = 0.011). There was no treatment (p > 0.554) or Treatment^*Time interaction (p > 0.471) for plasma prolactin concentration or body temperature. In conclusion, alterations in caudal artery hemodynamics were detected when cows were fed 529 and 2115 μg ergot alkaloids per kg dry matter per day for 1 week. The caudal artery was more sensitive to ergot alkaloids than the median sacral and internal iliac arteries. Our results partially support the hypothesis of a dose-response effect of ergot alkaloids in feed on hemodynamics.

Current methods for mycotoxins analysis and innovative strategies for their reduction in cereals: an overview

Mycotoxins are secondary metabolites produced by moulds in food that are considered a substantial issue in the context of food safety, due to their acute and chronic toxic effects on animals and humans. Therefore, new accurate methods for their identification and quantification are constantly developed in order to increase the performance of extraction, improve the accuracy of identification and reduce the limit of detection. At the same time, several industrial practices have shown the ability to reduce the level of mycotoxin contamination in food. In particular, a decrease in the amount of mycotoxins could result from standard processes naturally used for food processing or by procedures strategically introduced during processing, with the specific aim of reducing the amount of mycotoxins. In this review, the current methods adopted for accurate analyses of mycotoxins in cereals (aflatoxins, ochratoxins, trichothecenes, fumonisins) are discussed. In addition, both conventional and innovative strategies adopted to obtain safer finished products from common cereals intended for human consumption will be explored and analysed. © 2018 Society of Chemical Industry.