Animal feeds may contain exogenous compounds that can induce toxicity when ruminants ingest them. These toxins are secondary metabolites originating from various sources including plants, bacteria, ...algae and fungi. Animal feed toxins are responsible for various animal poisonings which negatively impact the livestock industry. Poisoning is more frequently reported in newly exposed, naïve ruminants while 'experienced' ruminants are observed to better tolerate toxin-contaminated feed. Ruminants can possess detoxification ability through rumen microorganisms with the rumen microbiome able to adapt to utilise toxic secondary metabolites. The ability of rumen microorganisms to metabolise these toxins has been used as a basis for the development of preventative probiotics to confer resistance against the poisoning to naïve ruminants. In this review, detoxification of various toxins, which include plant toxins, cyanobacteria toxins and plant-associated fungal mycotoxins, by rumen microorganisms is discussed. The review will include clinical studies of the animal poisoning caused by these toxins, the toxin mechanism of action, toxin degradation by rumen microorganisms, reported and hypothesised detoxification mechanisms and identified toxin metabolites with their toxicity compared to their parent toxin. This review highlights the commercial potential of rumen inoculum derived probiotics as viable means of improving ruminant health and production.
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Natural toxins are poisonous secondary metabolites produced by living organisms, which are typically not harmful to the organisms themselves but can impact on human or animal health when consumed ....
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•All stingless bee honeys (SBH) failed CODEX honey standard but partially met MS2683.•Trehalulose was the main sugar in all SBH and notably higher in G. thoracica honey.•Malaysian and Australian SBH ...have distinctly different physicochemical properties.
Stingless bee honey (SBH) of four stingless bee species (Heterotrigona itama, Geniotrigona thoracica, Tetragonula carbonaria, and Tetragonula hockingsi) from two geographic regions (Malaysia and Australia, n = 36) were studied for their physicochemical parameters, including total phenolic and multi-elemental contents. Sugar analysis confirmed the prominent presence of trehalulose in all samples. All SBH failed to meet the CODEX Standard for honey moisture, free acidity, and total fructose plus glucose levels. One-way ANOVA, principal component analysis (PCA) and hierarchical component analysis (HCA) confirm distinctive differences between Australian and Malaysian SBH with Australian SBH having significantly (P < 0.05) higher pH, total phenolic, total mineral, and electrical conductivity attributes. Toxic elements in all SBH were much lower than standard CODEX limit. The species G. thoracica produced honey with significantly (P < 0.05) higher trehalulose than both Australian bee species. This research will add value to SBH and hasten new international standards ensuring commercial viability, safety, quality, and marketability of SBH.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
is a genus of about 140 plant species, some of which are well-known for causing animal poisoning resulting in significant economic losses to the Australian livestock industry. The main poisonous ...species/subspecies include
(subsp.
and subsp.
),
and
(generally referred to as
). These plants contain a diterpenoid orthoester toxin, called simplexin.
poisoning is known to cause the death of cattle (
and
) or weaken surviving animals.
species are well-adapted native plants, and their diaspores (single seeded fruits) possess variable degrees of dormancy. Hence, the diaspores do not generally germinate in the same recruitment event, which makes management difficult, necessitating the development of integrated management strategies based on infestation circumstances (e.g., size and density). For example, the integration of herbicides with physical control techniques, competitive pasture establishment and tactical grazing could be effective in some situations. However, such options have not been widely adopted at the field level to mitigate ongoing management challenges. This systematic review provides a valuable synthesis of the current knowledge on the biology, ecology, and management of poisonous
species with a focus on the Australian livestock industry while identifying potential avenues for future research.
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Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. Examination of ...honey from five different stingless bee species across Neotropical and Indo-Australian regions has enabled for the first time the identification of the unusual disaccharide trehalulose as a major component representing between 13 and 44 g per 100 g of each of these honeys. Trehalulose is an isomer of sucrose with an unusual α-(1 → 1) glucose-fructose glycosidic linkage and known acariogenic and low glycemic index properties. NMR and UPLC-MS/MS analysis unambiguously confirmed the identity of trehalulose isolated from stingless bee honeys sourced across three continents, from Tetragonula carbonaria and Tetragonula hockingsi species in Australia, from Geniotrigona thoracica and Heterotrigona itama in Malaysia and from Tetragonisca angustula in Brazil. The previously unrecognised abundance of trehalulose in stingless bee honeys is concrete evidence that supports some of the reported health attributes of this product. This is the first identification of trehalulose as a major component within a food commodity. This study allows the exploration of the expanded use of stingless bee honey in foods and identifies a bioactive marker for authentication of this honey in associated food standards.
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Different methods have been applied in controlling contamination of foods and feeds by the carcinogenic fungal toxin, aflatoxin, but nevertheless the problem remains pervasive in developing ...countries. Curcumin is a natural polyphenolic compound from the spice turmeric (Curcuma longa L.) that has been identified as an efficient photosensitiser for inactivation of Aspergillus flavus conidia. Curcumin mediated photoinactivation of A. flavus has revealed the potential of this technology to be an effective method for reducing population density of the aflatoxin-producing fungus in foods. This study demonstrates the influence of pH and temperature on efficiency of photoinactivation of the fungus and how treating spore-contaminated maize kernels affects aflatoxin production. The results show the efficiency of curcumin mediated photoinactivation of fungal conidia and hyphae were not affected by temperatures between 15 and 35 °C or pH range of 1.5–9.0. The production of aflatoxin B1 was significantly lower (p < 0.05), with an average of 82.4 μg/kg as compared to up to 305.9 μg/kg observed in untreated maize kept under similar conditions. The results of this study indicate that curcumin mediated photosensitization can potentially be applied under simple environmental conditions to achieve significant reduction of post-harvest contamination of aflatoxin B1 in maize.
•Photosensitization-curcumin inactivated conidia and hyphae of Aspergillus flavus.•Conidia and hyphae inactivation of Aspergillus flavus was not affected by pH or temperature.•Photosensitization-Curcumin significantly reduced the production of aflatoxin B1 in maize kernels
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Pimelea poisoning of cattle, historically known as St. George Disease or Marree Disease, is a prevailing issue in arid grazing regions of inland Australia. Ingestion of the toxic native Pimelea ...species that contain the secondary metabolite simplexin, a diterpene orthoester with potent protein kinase C activity, induces diarrhoea, characteristic oedema and potentially fatal right-sided heart failure in cattle. Outbreaks of toxic Pimelea in the grazing field depend on seasonal prevalence. However, all stages of the plant carry the toxin, from seeds, juvenile plants to dead plant material. Livestock generally avoid consuming green Pimelea plants and only consume toxic Pimelea when pasture is minimal or where Pimelea growing through grass tussocks results in inadvertent ingestion. Our knowledge base of Pimelea poisoning has greatly improved with past research, yet the health hazards for livestock grazing in Pimelea affected pastures remains a significant issue whilst the ongoing search to develop effective strategies to mitigate poisoning continues. The goal of this review is to collate historical and recent research giving an overview of the current understandings of Pimelea poisoning, the toxin, its toxic effects and progress made towards remedies to alleviate the effects of Pimelea intoxication.
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•Native Pimelea plants in semi-arid Australia contain the toxin simplexin, a daphnane orthoester.•Simplexin has potent protein kinase C activity and is responsible for Pimelea poisoning of cattle.•Field weathered seed retains toxicity and poisoning occurs even in the absence of living plants.•No known cure exists resulting in significant annual economic losses.•Ongoing research may provide strategies to mitigate or eliminate poisoning events.
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Lindl is a little-understood Australian native plant, with irregular field emergence, causing significant poisoning to grazing livestock. The study aims to examine the form of dormancy exhibited by
...and determine how key environmental conditions, such as alternating temperature and light conditions, moisture availability, substrate pH and burial depth, affect its germination and emergence. The study concludes that
has a complex dormancy mechanism. This comprises a physical component that can be partly removed by fruit scarification, a metabolic dormancy that can be overcome by gibberellic acid (GA
), and a suspected third mechanism based on a water-soluble germination inhibitor. The results showed that scarified single seeded fruit (hereafter seed) with GA
treatment gave the highest germination percentage (86 ± 3%) at 25/15 °C, with good germination rates at other temperature regimes. Light exposure stimulated germination, but a significant proportion of seeds still germinated in the dark. The study also found that seeds could germinate under water-limited conditions and a wide range of pH levels (4 to 8). Seedling emergence was inhibited when seeds were buried below 3 cm in soil.
emergence in the field commonly occurs from Autumn to Spring. Understanding its dormancy mechanism and recognizing its triggers for germination will enable better prediction of outbreaks. This can help landholders prepare for emergence and help manage seedbank build-up in pastures and crops.
Pimelea poisoning of cattle is a unique Australian toxic condition caused by the daphnane orthoester simplexin present in native Pimelea pasture plants. Rumen microorganisms have been proposed to ...metabolise simplexin by enzymatic reactions, likely at the orthoester and epoxide moieties of simplexin, but a metabolic pathway has not been confirmed. This study aimed to investigate this metabolic pathway through the analysis of putative simplexin metabolites. Purified simplexin was hydrolysed with aqueous hydrochloric acid and sulfuric acid to produce target metabolites for UPLC-MS/MS analysis of fermentation fluid samples, bacterial isolate samples, and other biological samples. UPLC-MS/MS analysis identified predicted hydrolysed products from both acid hydrolysis procedures with MS breakdown of these putative products sharing high-resolution accurate mass (HRAM) fragmentation ions with simplexin. However, targeted UPLC-MS/MS analysis of the biological samples failed to detect the H2SO4 degradation products, suggesting that the rumen microorganisms were unable to produce similar simplexin degradation products at detectable levels, or that metabolites, once formed, were further metabolised. Overall, in vitro acid hydrolysis was able to hydrolyse simplexin at the orthoester and epoxide functionalities, but targeted UPLC-MS/MS analysis of biological samples did not detect any of the identified simplexin hydrolysis products.
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Pimelea poisoning of cattle causes distinct symptoms and frequently death, attributable to the toxin simplexin. Pimelea poisoning was induced via addition of ground Pimelea trichostachya plant to the ...daily feed in a three-month trial with Droughtmaster steers. The trial tested four potential mitigation treatments, namely, biochar, activated biochar, bentonite, and a bacterial inoculum, and incorporated negative and positive control groups. All treatments tested were unable to prevent the development of simplexin poisoning effects. However, steers consuming a bentonite adsorbent together with Pimelea showed lesser rates-of-decline for body weight (P < 0.05) and four hematological parameters (P < 0.02), compared to the positive control group fed Pimelea only. Microbiome analysis revealed that despite displaying poisoning symptoms, the rumen microbial populations of animals receiving Pimelea were very resilient, with dominant bacterial populations maintained over time. Unexpectedly, clinical edema developed in some animals up to 2 weeks after Pimelea dosing was ceased.
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