Combined functional additives for farm animals are an important segment in the implementation of the antibiotic resistance strategy and an effective mechanism for restoring animal homeostasis in mixed pathologies

The article provides an overview of the global situation related to the problem of antibiotic resistance, the search for rational ways to solve the problem and proposals for the imperative introduction of functional feed additives into the nutritional plan of animals in order to increase the resistance of the animal body and reduce the toxic load on the gastrointestinal and hepatobiliary systems.

Phenetic phytoindication and biotesting of soils in recreation zones of Tver city

Исследованы фенофонды ценопопуляций подорожника большого (Plantago major L.) и сныти обыкновенной (Aegopodium podagraria L.) в рекреационных зонах г. Твери с разным уровнем загрязнения почв тяжелыми металлами (ТМ). Параллельно проведено биотестирование почв модельных биотопов по параметрам развития семян тест-растений - горчицы белой (Sinapis alba L.), кресс-салата (Lepidium sativum L.), сорго черного (Sorghum nigrum L.) в соответствии с ГОСТ Р ИСО 18763-2019. По мере возрастания суммарной токсической нагрузки на биотопы среднее число фенов у сныти и подорожника снижается. Однако доля редких фенов у сныти возрастает, а у подорожника уменьшается. Общие показатели фенетического разнообразия (среднее число и доля редких фенов) у сныти коррелируют с суммарной токсической нагрузкой на почвы в большей степени, чем у подорожника. Параметры развития семян разных видов тест-растений неоднозначно отражают фитотоксичность почв. В большей степени с суммарным содержанием ТМ в почве коррелируют показатели всхожести семян и размеры корней проростков у горчицы. Данные по фитоиндикации биотопов на основе фенетических показателей ценопопуляций сныти и, в меньшей степени подорожника, в целом согласуются с результатами биотестирования почв. The phenofonds of Plantago major L. and Aegopodium podagraria L. cenopopulations in recreation zones of Tver with different levels of soil contamination with heavy metals (HM) were studied. In parallel, biotesting of soils of model biotopes was carried out according to the parameters of test plants seeds development - Sinapis alba L., Lepidium sativum L., Sorghum nigrum L. in accordance with ISO 18763:2016. With an increase in the total toxic load on biotopes, the average number of phenes in P. major and A. podagraria decreases. However, the share of rare phenes increases in A. podagraria, and decreases in P. major. The general indicators of phenetic diversity (average number and proportion of rare phenes) in A. podagraria correlate with the total toxic load on soils to a greater extent than in P. major. The development parameters of seeds of different species of test plants ambiguously reflect the phytotoxicity of soils. To a greater extent, the indicators of seed germination and the seedlings root size in S. alba correlate with the total content of HM in the soil. The data on the phytoindication of biotopes based on the phenetic indices of the cenopopulations of A. podagraria and, to a lesser extent, P. major, are generally consistent with the results of soil biotesting.

Toxicological and ecotoxicological pressure assessment on the use of synthetic pesticides in Sancti Spíritus, Cuba

A study to quantify the toxicity and ecotoxicological pressure of pesticides in the Sancti Spíritus province, Cuba, was carried out between 2011 and 2014. A longitudinal descriptive work was designed for the study period to identify potential risks to the environment and also to human health associated with the use of pesticides in the country. The Spread Equivalents (ƩSeq) and Pesticide Occupational and Environmental Risk (POCER) indicators, as well as the Toxic Load (TL) methodology of Instituto Cubano de Sanidad Vegetal, were used to determine the toxicity and ecotoxicity of pesticide use. One hundred and twenty-four active ingredients corresponding to 62 chemical families were applied in the province during the study period. Organophosphates, triazoles, sulfonylurea, pyrethroids, inorganic compounds (such as copper), carbamates, dithiocarbamates, neonicotinoids, aryloxyphenoxypropionates, and organochlorines predominated due to their use frequency. The use of toxic pesticides, and the lack of personal protection equipment, among others, made workers, residents, and applicators the toxicological modules with the highest risk of exposure. On the other hand, aquatic organisms, and the persistence of the pesticides in the soil and in groundwater, are the modules with the highest ecotoxicological pressure. By using the POCER and ƩSeq indicators, a more accurate toxicity and ecotoxicity assessment for certain pesticides can be performed in Cuba, in comparison to the one obtained when using only the TL equation currently employed in the country. In addition, substituting the most toxic pesticides (e.g., parathion, endosulfan, bifenthrin, copper oxychloride, mancozeb, paraquat, diquat, and ametryn) with less toxic ones (e.g., cypermethrin, tebuconazole, triadimenol, and bispyribac-sodium) could help reduce synthetic pesticide pressure on humans and the environment.

O antigen restricts lysogenization of non-O157 Escherichia coli strains by Stx-converting bacteriophage phi24B

Acquisition of new prophages that are able to increase the bacterial fitness by the lysogenic conversion is believed to be an important strategy of bacterial adaptation to the changing environment. However, in contrast to the factors determining the range of bacteriophage lytic activity, little is known about the factors that define the lysogenization host range. Bacteriophage phi24B is the paradigmal model of Stx-converting phages, encoding the toxins of the Shiga-toxigenic E. coli (STEC). This virus has been shown to lysogenize a wide range of E. coli strains that is much broader than the range of the strains supporting its lytic growth. Therefore, phages produced by the STEC population colonizing the small or large intestine are potentially able to lysogenize symbiotic E. coli in the hindgut, and these secondary lysogens may contribute to the overall patient toxic load and to lead to the emergence of new pathogenic STEC strains. We demonstrate, however, that O antigen effectively limit the lysogenization of the wild E. coli strains by phi24B phage. The lysogens are formed from the spontaneous rough mutants and therefore have increased sensitivity to other bacteriophages and to the bactericidal activity of the serum if compared to their respective parental strains.

VETERINARY SANITARY EXPERTISE OF MEAT OF BROILER CHICKENS URAL PRODUCERS

Poultry farming, providing replenishment of the food basket with high-quality and inexpensive products, plays an important role in the formation of food security in Russia. Veterinary and sanitary examination of poultry products in the context of the ecological component of the safety of agricultural raw materials is an important and timely task within the framework of government documents of the Russian Federation in the field of health protection of the country's population. According to the results of the physical, chemical and microbiological tests of chilled broiler chicken carcasses of the 1st grade of the Ural processors («Ravis – Sosnovskaya poultry farm», «Argayashskaya poultry farm», «Nagaybak poultry complex»), the raw materials were recognized as fresh, in terms of the amount of pesticides, antibiotics and heavy metals – safe. The content of protein, fat and moisture in all studied samples corresponded to the average values. A detailed study of the mineral composition revealed negative deviations in the amount of Fe and Se in all carcass samples. The products of the Argayash poultry farm against the background of analogous samples contained less fat and moisture with identical protein values, occupied an intermediate position in the amount of essential elements – Ca, Fe, Na, P, Zn, was distinguished by the absence of minerals that increase the toxic load on the human body – Ni, Ti , Ba, Ga, Li, which formed its competitive advantages.

Difenoconazole-based fungicides for orchard protection

A comparative assessment of the effectiveness of 4 difenoconazole-based fungicides in the fight against apple scab in the Krasnodar region and the Rostov Region for several years has been carried out. The preparations Sercadis Plus, SC were applicated at a rate of application of 1.2 l/ha; Embrelia, SC – 1.5 l/ha; Cidely Top, DС – 0.7 l/ha and Tersel, WG – 2.5 kg/ha three times, against different infectious backgrounds, starting with the “pink bud” phenophase (the end of flowering stage). The following apple cultivars were used: Idared, Champion and Golden Delicious. Research has shown that all studied fungicides significantly reduced the scab infestation of apple leaves and fruits. This resulted in obtaining additional yield in the range of 12.6-46.0%. The fruit grade was high after the treatments: 93.0-100% in the Krasnodar region and 81.5-91.5% in the Rostov Region, while in the nil treatment the percentages of standard products were 68.5% and 44.6%, respectively. According to the toxic load indicator, difenoconazole-based fungicides, such as Embrelia, SC (11.6 LD50 per hectare), were less dangerous for the fruit cenosis.

Hygiene of microbiota of broiler chickens with introduction of sorbent additive based on tripoli

Currently, mycotoxicosis and losses of poultry farming from non-communicable diseases are not a solved problem. The microflora of the gastrointestinal tract of broiler chickens, under the influence of the feed components, undergoes a qualitative change throughout the entire period of poultry growing. Authors in dynamics carried out studies to study the qualitative and quantitative composition of the microbiota of broiler chickens and its response to the impact of the feed additive «MeKaSorb». Introduction of various sorbent additives into the diet, including those based on tripoli, improves detoxification processes, regulates mineral, enzyme, hormonal and vitamin metabolism in the body of poultry. Ensuring maximum hygiene of the broiler microbiota allows to reduce the toxic load on the body of young poultry, ensure high safety of the livestock and get the maximum amount of products. Improving the sanitary quality and safety of food, as well as the prevention of diseases in poultry and humans is the most important task that must be addressed by the chief specialists at poultry farms. It has been established that the introduction of a patented additive-sorbent of mycotoxins based on tripoli «MeKaSorb» ensures the hygiene of the microbiota of broiler chickens, stimulates the growth and development of lacto- and bifidoflora, reduces the number of aerobic microorganisms and inhibits the reproduction and colonization of the gastrointestinal tract by bacteria of the intestinal group. Feed additive «MeKaSorb» is recommended for use in compound feeds for preventive purposes when growing poultry.

Identifying agricultural pesticides that may pose a risk for birds

In this study, we analyze changing patterns of pesticide use in agriculture in Great Britain over the 1990–2016 period, with respect to the risk they pose to birds. The weight of pesticides applied decreased by 51% between 1990 and 2016, but the area treated increased by 63% over the same period. Over this period, there has been considerable turnover in the pesticides used. The European Union (including Great Britain until 2020) has restricted or banned many pesticides for agricultural use, including organophosphates and carbamates. However, new generations of active substances have been introduced, such as the neonicotinoids, some of which have since been banned. In this analysis, we estimate the annual ‘toxic load’ of agricultural pesticide use in Great Britain for birds, measured as the total number of LD50 doses for corn buntings, Emberiza calandra. We have previously performed similar analyses for bees, for which the total toxic load increased six-fold during this period. In contrast, for birds the total toxic load fell by 80.5%, although still correspond to 8.3e+11 corn bunting LD50 doses in 2016. The decrease in toxicity is largely due to declining use of highly toxic organophosphates in recent years. We identify the pesticides in current use that may pose the highest risk to birds, which include a mix of insecticides, herbicides, fungicides, molluscicides, acaricides and plant growth regulators. The insecticide ethoprop was ranked highest in 2016, with a toxic load of 71 billion potential corn bunting kills. Some of the other chemicals presenting a high toxic load, such as the herbicide chlormequat, are not highly toxic to birds (in terms of LD50) but are used in very large quantities. However, it is important to stress that, in reality, only a tiny proportion of pesticides applied will be ingested by birds, and this will vary according to timing and method of application, persistence of the active substance and many other factors. We further note that impacts of pesticides on birds might often be indirect, for example via depleting their food supply, and that sublethal impacts may occur at much lower doses than the LD50, neither of which do we investigate here. Nonetheless, we suggest that this is a useful approach to highlight pesticides that might be worth closer study with regard to possible impacts.

Removal of Cu (II) from Industrial Wastewater Using Mechanically Activated Serpentinite

We investigate with this study the effectiveness of mechanically activated serpentinite in capturing Cu (II) from the multi-constituent acidic wastewater of the pit lakes of the Agios Philippos mine (Greece), proposing specific areas with serpentinites suitable for such environmental applications. For this purpose ultramafic rock samples that are characterized by variable degrees of serpentinization from ophiolitic outcrops exposed in the regions of Veria-Naousa and Edessa have been examined regarding their capacity to remove the toxic load of Cu (II) from wastewater after having been mechanically activated through a Los Angeles (LA) machine (500, 1000 and 1500 revolutions). The more serpentinized and mechanically activated samples, as they have been characterized after a combination of various mineralogical, petrographic, geochemical analyses as well as after different stresses of abrasion and attrition, seem to be more effective in Cu removal than the less serpentinized ones. Selective removal of Cu (II) in the wroewolfeite phase was obtained by using the mechanically activated highly serpentinized ultramafic rocks. Furthermore, areas with highly serpentinized ultramafic rocks defined after petrographic mapping, using GIS method, which can potentially be used as filters for the effective Cu (II) removal from industrial wastewater are suggested.