The impact of mycotoxins on dairy cow health and milk production

В статье представлены материалы о влиянии микотоксинов на здоровье и продуктивность молочного скота. В настоящее время наибольшую опасность для здоровья животных представляют яды микроскопических грибов — микотоксины, что требует разработки методов их устранения по всей цепочке — от поля до потребителя. Известно, что споры грибов, продуцирующих токсины, живут в почве и оттуда передаются растениям, а затем зёрнам. Микотоксины — это вторичные метаболиты грибов, такие как афлатоксины (AF), продуцируемые видами Aspergillus, фумонизины (FUM), зеараленон (ZEN), токсин T-2 (T-2) дезоксиниваленол (DON), продуцируемый видами Fusarium, охратоксин A (OTA), продуцируемый видами Penicillium, и многие другие. Потребление кормов, загрязнённых этими токсинами, вызывает у животных микотоксикозы, которые характеризуются рядом клинических признаков в зависимости от вида токсинов. У животных снижается продуктивность и поедаемость кормов, увеличивается восприимчивость к различным заболеваниям. Существует две формы микотоксикозов: острые микотоксикозы, возникающие из-за потребления высокой разовой дозы микотоксинов, и хронические микотоксикозы из-за постоянного потребления низких уровней микотоксинов в течение продолжительного времени. Хронический токсикоз, вызванный низким уровнем воздействия микотоксинов в течение продолжительного времени, представляет собой более распространённую проблему для здоровья животных и качества пищевых продуктов для людей. В целом объёмистые корма и зерновые компоненты, входящие в состав рациона, подвержены загрязнению афлатоксинами на всех этапах производства кормов, таких как сбор, транспортировка, хранение, переработка и упаковка. В последнее время учёные стали уделять больше внимания загрязнению кормов микотоксинами и механизмам борьбы с разными группами токсинов. Основной задачей при производстве кормов является снижение концентрации токсинов на всех этапах — от поля до рациона животных. This article focuses on the effect of mycotoxins on dairy cow health and productivity. To this day toxins produced by various fungi are one of the most serious dangers for cattle. It is known that spores usually contaminate plant and later grain material from soil. Mycotoxins are secondary metabolites such as aflatoxins (AF) produced by Aspergillus spp., fumonisins (FUM), zearalenone (ZEN), T-2 (T-2), deoxynivalenol (DON) produced by Fusarium spp., ochratoxin A (OTA) produced by Penicillium spp., and many others. Toxin-contaminated forage causes mycotoxicoses of different severity depending on toxin type. Livestock shows low productivity and appetite but high susceptibility to diseases There are two types of mycotoxicoses: acute mycotoxicoses, caused by high concentration of toxins and the chronic ones, occurring due to constant long consumption of low toxin levels. Chronic toxicosis is a more common problem for animal health and food quality. Bulk and grain feed are highly affected by aflatoxins at such production stages as harvesting, transporting, storage, processing and packaging. Lately scientists drew more attention to toxin contamination issue and methods controlling their accumulation. The main task when producing forage is to reduce toxin concentration at all the production stages.

The Effects of Ferric Sulfate (Fe2(SO4)3) on the Removal of Cyanobacteria and Cyanotoxins: A Mesocosm Experiment

Cyanobacterial blooms are a global concern. Chemical coagulants are used in water treatment to remove contaminants from the water column and could potentially be used in lakes and reservoirs. The aims of this study was to: 1) assess the efficiency of ferric sulfate (Fe2(SO4)3) coagulant in removing harmful cyanobacterial cells from lake water with cyanobacterial blooms on a short time scale, 2) determine whether some species of cyanobacteria can be selectively removed, and 3) determine the differential impact of coagulants on intra- and extra-cellular toxins. Our main results are: (i) more than 96% and 51% of total cyanobacterial cells were removed in mesocosms with applied doses of 35 mgFe/L and 20 mgFe/L, respectively. Significant differences in removing total cyanobacterial cells and several dominant cyanobacteria species were observed between the two applied doses; (ii) twelve microcystins, anatotoxin-a (ANA-a), cylindrospermopsin (CYN), anabaenopeptin A (APA) and anabaenopeptin B (APB) were identified. Ferric sulfate effectively removed the total intracellular microcystins (greater than 97% for both applied doses). Significant removal of extracellular toxins was not observed after coagulation with both doses. Indeed, the occasional increase in extracellular toxin concentration may be related to cells lysis during the coagulation process. No significant differential impact of dosages on intra- and extra-cellular toxin removal was observed which could be relevant to source water applications where optimal dosing is difficult to achieve.

Analytical Solutions of a Two-Compartment Model Based on the Volume-Average Theory for Blood Toxin Concentration during and after Dialysis

Accurate prediction of blood toxin concentration during and after dialysis will greatly contribute to the determination of dialysis treatment conditions. Conventional models, namely single-compartment model and two-compartment model, have advantages and disadvantages in terms of accuracy and practical application. In this study, we attempted to derive the mathematical model that predicts blood toxin concentrations during and after dialysis, which has both accuracy and practicality. To propose the accurate model, a new two-compartment model was mathematically derived by adapting volume-averaging theory to the mass transfer around peripheral tissues. Subsequently, to propose a practical model for predicting the blood toxin concentration during dialysis, an analytical solution expressed as algebraic expression was derived by adopting variable transformation. Furthermore, the other analytical solution that predicts rebound phenomena after dialysis was also derived through similar steps. The comparisons with the clinical data revealed that the proposed analytical solutions can reproduce the behavior of the measured blood urea concentration during and after dialysis. The analytical solutions proposed as algebraic expressions will allow a doctor to estimate the blood toxin concentration of a patient during and after dialysis. The proposed analytical solutions may be useful to consider the treatment conditions for dialysis, including the rebound phenomenon.

Sensitivity analysis of solute kinetics in a four compartmental model for hemodialysis patients

Sensitivity Analysis of the most advanced four compartmental mathematical model explaining solute kinetic in the hemodialysis patients was performed on the basis of the data collected from six patients with different Body Mass Indices (BMIs). The toxin concentration in all compartments increases with the decrease in the BMIs of the patients. The clearance rate, kclear, and the volume of extracellular compartment, VE, are the most sensitive while the volume of the muscle tissue compartment, VMT, and the clearance rate, kMT, are the least sensitive parameters during dialytic interval. The production rate, G, and the volume of the extracellular compartment, VE, are the most sensitive while kclear and kE, AT are the least sensitive parameters of all parameters during the interdialytic interval. The overall production rate, G, remains more sensitive than the clearance rate, kclear during one complete cycle.

Increasing plant density increases Bt toxin concentration of boll wall in cotton by decreasing boll setting speed

Background In order to uncover the mechanism of significantly reduced insect resistance at the late developmental stage in cotton (Gossypium hirsutum L.), the relationship between boll setting rate under different planting densities and Bacillus thuringiensis (Bt) insecticidal concentrations in the boll wall were investigated in the present study. Two studies were arranged at Yangzhou, China during the 2017–2018 cotton growth seasons. Five planting densities (15 000, 25 000, 45 000, 60 000 and 75 000 plants per hectare) and the flower-removal treatment were imposed separately on Bt cotton cultivar Sikang3 to arrange different boll setting rates, and the boll setting rates and Bt toxin content were compared. Results Higher boll setting rate together with lower Bt toxin contents in boll wall was observed under low planting density, whereas lower boll setting rate and higher Bt toxin contents were found under high planting density. Also, higher Bt protein concentration was associated with higher soluble protein content, glutamic-pyruvic transaminase (GPT), and glutamic oxaloacetate transaminase (GOT) activities, but lower amino acid content, and protease and peptidase activities. It was further confirmed that a higher boll setting rate with lower Bt protein content under flower-removal. Conclusions This study demonstrated that the insecticidal efficacy of boll walls was significantly impacted by boll formation. Reduced protein synthesis and enhanced protein degradation were related to the reduced Bt toxin concentration.

Isolation and detailed characterisation of the first sterigmatocystin hyperproducer mould strain in Hungary

Aspergillus strains were isolated from Hungarian mills in order to get information on the appearance of sterigmatocystin (ST) producing moulds, whose presence has never been demonstrated in Hungary. Fungal isolates were classified into nine morphotypes, sections Nigri, Nidulantes, Versicolores (two morphotypes), Circumdati, Flavi (two morphotypes), Clavati and Terrei by classical mycological assays. ST producing strains could be classified into section Versicolores. ST production of the isolates was assessed by liquid and solid phase growth experiments and compared to ST producing reference strains: Aspergillus pepii SzMC 22332, Aspergillus versicolor SzMC 22333, Aspergillus griseoaurantiacus SzMC 22334 and Aspergillus nidulans RDIT9.32. Four of our isolates marked as Km11, Km14, Km26 and Km31 showed ST production in liquid medium. ST production on solid phase corn grit substrate was measured after three weeks of incubation, and Km26 isolate proved to be the most prominent with a toxin concentration of 277.1 μg g−1, surpassing all reference strains. The toxin-producing ability of Km26 isolate was also tested in a field experiment, where corn was infected. By the end of the experiment, ST level of 19.56 μg kg−1 was measured in infected corn.Molecular taxonomic identification of the Km26 strain was performed using internal transcribed spacer (ITS), calmodulin and tubulin sequence analyses. Based on these studies, strain Km26 was identified as Aspergillus creber.Here we report that an ST-producing A. creber strain has appeared in Hungary, and the Km26 strain is the first known extreme ST-producing mould in this country. As a result of climate change, aflatoxin B1 producing Aspergillus flavus strains have appeared in Hungary in the last decade. As strain Km26 is the only A. creber isolate in Hungary so far, there is no sign of mass prevalence, and due to the lower temperature optimum of the species compared to A. flavus, its appearance is probably not related to climate change.

Lipophilic Toxins in Wild Bivalves from the Southern Gulf of California, Mexico

Most of the shellfish fisheries of Mexico occur in the Gulf of California. In this region, known for its high primary productivity, blooms of diatoms and dinoflagellates are common, occurring mainly during upwelling events. Dinoflagellates that produce lipophilic toxins are present, where some outbreaks related to okadaic acid and dinophisystoxins have been recorded. From January 2015 to November 2017 samples of three species of wild bivalve mollusks were collected monthly in five sites in the southern region of Bahía de La Paz. Pooled tissue extracts were analyzed using LC-MS/MS to detect lipophilic toxins. Eighteen analogs of seven toxin groups, including cyclic imines were identified, fortunately individual toxins did not exceed regulatory levels and also the total toxin concentration for each bivalve species was lower than the maximum permitted level for human consumption. Interspecific differences in toxin number and concentration were observed in three species of bivalves even when the samples were collected at the same site. Okadaic acid was detected in low concentrations, while yessotoxins and gymnodimines had the highest concentrations in bivalve tissues. Although in low quantities, the presence of cyclic imines and other lipophilic toxins in bivalves from the southern Gulf of California was constant.

Removal of aflatoxin b1 and t-2 toxin by bacteria isolated from commercially available probiotic dairy foods

This study isolated lactic acid bacteria from commercially available probiotic foods to determine their capacity to remove aflatoxin B1 (AFB1) and trichothecene-2 (T-2). The removal rates by original live and heat-treated cells of lactic acid bacteria (LAB) were compared to test the effect of heat treatment on efficacy. LAB is capable to remove up to 46% of AFB1 and up to 45% of T-2 toixn. The toxin removal capability increased as toxin concentration increased despite bacterial cell viability declining. Surprisingly, the denatured LAB removed greater percentages of AFB1 (up to 62%) and T-2 (up to 52%) than live bacterial cells ( P < 0.05), lending support to the hypothesis that there is higher binding of toxins to the cell membrane of nonviable cells. The research provided practical evidences, which suggest that when ingested into the gut biota, LAB could likely reduce absorption of AFB1 and T-2 from contaminated foods.