The Impact of Acids Approved for Use in Foods on the Vitality of Haemonchus Contortus and Strongyloides Papillosus (Nematoda) Larvae

Survival of Nematode Larvae Strongyloides papillosus and Haemonchus contortus under the Influence of Various Groups of Organic Compounds

Many chemically synthesized xenobiotics can significantly inhibit the vitality of parasitic nematodes. However, there is yet too little research on the toxicity of such contaminating compounds toward nematodes. Compounds that are present in plants are able to inhibit the vitality of parasitic organisms as well. According to the results of our laboratory studies of toxicity, the following xenobiotics caused no decrease in the vitality of the larvae of Strongyloides papillosus and Haemonchus contortus: methanol, propan-2-ol, propylene glycol-1,2, octadecanol-1, 4-methyl-2-pen-tanol, 2-ethoxyethanol, butyl glycol, 2-pentanone, cyclopentanol, ortho-dimethylbenzene, dibutyl phthalate, succinic anhydride, 2-methylfuran, 2-methyl-5-nitroimidazole. Strong toxicity towards the nematode larvae was exerted by glutaraldehyde, 1,4-diethyl 2-methyl-3-oxobutanedioate, hexylamine, diethyl malonate, allyl acetoacetate, tert butyl carboxylic acid, butyl acrylate, 3-methyl-2-butanone, isobutyraldehyde, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, 3-methylbutanal, cyclohexanol, cyclooctanone, phenol, pyrocatechin, resorcinol, naphthol-2, phenyl ether, piperonyl alcohol, 3-furoic acid, maleic anhydrid, 5-methylfurfural, thioacetic acid, butan-1-amine, dimethylformamide, 1-phenylethan-1-amine, 3-aminobenzoic acid. Widespread natural compounds (phytol, 3-hydroxy-2-butanone, maleic acid, oleic acid, hydroquinone, gallic acid-1-hydrate, taurine, 6-aminocaproic acid, glutamic acid, carnitine, ornithine monohydrochloride) had no negative effect on the larvae of S. papillosus and H. contortus. A powerful decrease in the vitality of nematode larvae was produced by 3,7-dimethyl-6-octenoic acid, isovaleric acid, glycolic acid, 2-oxopentanedioic acid, 2-methylbutanoic acid, anisole, 4-hydroxy-3-methoxybenzyl alcohol, furfuryl alcohol. The results of our studies allow us to consider 28 of the 62 compounds we studied as promising for further research on anti-nematode activity in manufacturing conditions.

Influence of aromatic substances on locomotor activity of Deroceras agreste slugs

The global climate changes are causing an increase in the number and harmfulness of slugs. Deroceras agreste (Linnaeus, 1758) (Stylommatophora, Agriolimacidae) is a polyphagous phytophage that damages over 150 species of plants, including many vegetables, cultivated berries and grasses. Other than decrease in yield, slugs cause deterioration of consumer qualities of the products, promote infections of plants, and are intermediate hosts of some parasites of mammals and birds. Thus, slugs impose great losses on agricultural farming, and therefore the objective of our study was determining the variability of locomotor activity of D. agreste slugs in reaction to aromatic substances. We determined repellent or attractive effects of those substances for the purpose of further using the obtained data for plant protection. We tested 52 substances and their mixtures, which were conditionally divided into the following groups: chemical solvents, plant extracts, aromatizers, organic acids and synthetic cosmetic additives. Only dimethyl sulfoxide could be identified as an attractant. All the rest of the substances increased the speed of the slugs to various degrees, but had no significant effect on the direction of the animals’ movement. Gasoline increased the speed of the slugs’ movement by 3.20 times, xylene by 4.56. The most effective organic acids and aromatizers to increase the moving speed of slugs were avobenzone and formic acid: the first caused a 2.83-fold increase in the moving speed, the other a 3.16-fold increase. Only one of 13 aromatic substances changed the direction of the slugs’ movement during the experiment – β-ionone. As with the plant extracts, the highest effect on locomotor activity of slugs was exerted by tree bark of Quillaja saponaria (3.64-fold) and Aesculus hippocastanum extract (4.33-fold). Furthermore, together with Capsicum frutescens, they changed the direction the mollusks were moving in, and therefore could be used as repellents. Synthetic cosmetic additives hydrolyzed silk and chrysalide oil exerted the greatest effects on the lcomotor activity of slugs (3.16 and 3.20 times, respectively). A total of 78.6% of the slugs moved away from chrysalide oil, and thus this oil may be suggested as a repellent, as well as mousse de babassu and cocamidopropyl betaine (84.6% and 78.6%, respectively). Therefore, a large amount of the tested substances to one or another extent made the slugs move faster, but most of them did not alter the direction in which the slugs were moving.

Effects of aromatic compounds on movement activity of Pyrrhocoris apterus in the conditions of a laboratory experiment

In the conditions of an urban environment, insects, including Pyrrhocoris apterus (Linnaeus, 1758) (Hemiptera, Pyrrhocoridae), are subject to dozens of volatiles: solvents, food flavorings, cosmetic products. For firebugs, some attract them, some scare them off, and to some they are indifferent. In this article, in the conditions of laboratory experiment, we evaluated the influence of chemical substances on rates of movement of firebugs. Under the influence of the substances we studied, there occurred no significant increase or decrease in the activity of firebugs. The most significant effect on rates of movement of firebugs was exerted by solvent, white spirit and solvent 646 p – firebugs travelled 12 cm distance for 24.2%, 49.6% and 58.7% of the time the control group did. Movement activity of firebugs was insignificantly decreased by aromatic extracts Royаl milk extract, Butcher’s broom extract and chrysalis oil: firebugs travelled 12 cm distance for 132.7%, 135.2% and 146.8% of time the control group. Aromatic substances likely interact with receptors on antennae of firebugs, and therefore the insects need additional time for orienting reactions, deciding whether those substances signal presence of potential food objects in the accessibility zone.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Prevalence of gastrointestinal helminths in ruminants in Ukraine: a 5-year meta-analysis

The production of environmentally friendly livestock products is currently receiving much attention, especially in the European Union. The problem of monitoring the quality and safety of meat and milk in modern conditions is relevant not only for Ukraine but also for the world community. The scientific substantiation of the methods of research on meat for sale subject to invasive diseases is especially important, as the product may pose risks to the consumer. One of the criteria for assessing the welfare of a herd is the prevalence of helminthiases in cattle. Ruminant parasitoses in Ukraine have always been and remain a separate, often significant, problem for veterinary specialists. Helminths have evolved to use a wide range of ecological niches. In this study, we tried to quantify the prevalence of helminthiases among ruminants (cattle, sheep and goats) in Ukraine. The relevant studies were searched for in the online databases. The meta-analysis included 15 publications from January 2015 to December 2020 which reported the spread of parasites in Ukraine. The research results show that the infestation of ruminants with gastrointestinal helminths on the territory of Ukraine is 56.7%. Egger’s regression test revealed no significant publication bias. During the period of pastured farming, stable parasitocenoses are formed in the body of ruminants. The parasitoses are caused by helminths (gastrointestinal strongyles, liver flukes, paramphistomas, dicrocelia). They are recorded in monoinvasions or mixed invasions. Ruminants, according to helminthological examination in different climatic zones, are constantly infested with trematodes. In Ukraine, the presence of three species of flukes has been confirmed in ruminants: Fasciola hepatica, Dicrocoelium dendriticum and Paramphistomum cervi. Parasitization by those species negatively affects the profitability of dairy farming. Trematodes cause significant economic losses: reduced milk productivity of cows, reduced live weight gain of young animals, negative impact on reproduction. At the same time, fascioliasis is socially significant and dangerous to humans. According to the analyzed literature sources, two types of cestodes have been registered in Ukraine: Moniezia benedeni and M. expansa. The epizootic situation regarding nematodes is just as fraught. That is the most numerous group of helminths, their fauna is represented by the following species: Strongyloides papillosus, Nematodirus spathiger, Bunostomum spp., Oesophagostomum radiatum, Haemonchus contortus, Toxocara vitulorum, Trichuris skrjabini, T. ovis and T. globulosa. It is proven that in cattle parasitocenoses are recorded more often than monoinvasions. The highest rates of prevalence of infection were observed when polyinvasion included gastrointestinal strongyles, namely from the order Strongylida. Strongyloides papillosus is the most common taxonomic representative, while Fasciola hepatica has the lowest prevalence of infection, especially in sheep. Updated data on helminthiasis will expand the screening strategy to maintain the health of farm ruminants and reduce economic losses.

Influence of Synthetic Flavorings on the Migration Activity of Tribolium confusum and Sitophilus granarius

Flavorings and volatile biologically active substances, used by humans for various purposes, may potentially have fumigating, repellent, or attractive effects on various species of anthropod storage pests. Tribolium confusum Jacquelin du Val, 1863 (Tenebrionidae) and Sitophilus granarius (Linnaeus, 1758) (Curculionidae) are the two most abundant pests of grain and grain products; the damage they cause to stored products of horticulture is 5–20% of the total yield of grain crops. In the experiment, we video-recorded migratory activity of beetles and evaluated it according to standard time periods (10, 20, 30, 60, and 120 seconds after the start of the experiment). No reliable influence of the 15 tested flavoring substances (benzyl alcohol, benzoic acid, toluene, hydroquinone, phenethyl alcohol, pinene, methylparaben, kojic acid, formic acid, isoamyl alcohol, tartaric acid, glycine, succinic acid, stearic acid, and ethylenediaminetetraacetic acid) on moving activity of Tribolium confusum was found. Exposure to benzyl alcohol brought a reliable decrease in locomotor activity of Sitophilus granarius (it exerted an attractant effect on imagoes as compared with the variant of the experiment without aromatic substances): 6.09 times more imagoes of S. granarius remained at a minimal distance from the aroma source than in the control, 6.07 more while exposed to hydroquinone, 5.50 to phenethyl alcohol, 4.50 to glycine, 3.44 to EDTA, 3.30 to toluene, 3.18 to methylparaben, 2.84 to succinic acid, 2.65 to benzoic acid, and 2.15 more when exposed to formic acid compared with the control variant of the experiment. Other surveyed flavoring substances (benzyl alcohol, pinene, kojic acid, isoamyl alcohol, tartaric acid, and stearic acid) had no significant effect on migratory activity of imagoes of S. granarius. The results allow us to recommend benzyl alcohol, hydroquinone, phenethyl alcohol, and glycine as potential luring substances or components of multicomponent flavoring mixtures during the assessment of the number of S. granarius in grain storage and processing facilities.

Pathohistological changes in the intestine, lungs and liver of sheep with spontaneous strongyloidiasis

Sheep diseases of invasive and non-invasive etiology are among the restrictive factors for Ukrainian sheep-breeding. The helminthiases are among the most widespread parasitical diseases, and particularly strongyloidiasis causes significant losses for sheep farms in cases of severe course. Young sheep are the most susceptible, showing growth and developmental lag, and death occurs in cases of high invasiveness due to severe pathologies induced by the parasites. Thus the aim of the present work was to study the morphological and histological changes in the intestine, lungs and liver of sheep with strongyloidiasis. Results of pathoanatomy showed that under spontaneous sheep strongyloidiasis with the intensity of the invasion from 50 to 136 specimens of nematodes, the main pathological changes occur at Strongyloides localization sites: intestine and parenchymatous organs (lungs and liver). Particularly, the small intestine showed catarrhal desquamative enteritis. Morphological changes of its mucosa demonstrated necrosis of the apical part of the villi, desquamation of epithelium, constriction and decrease of intestinal crypts. At the same time, massive diffusive cell infiltrates were detected in the intestinal mucosa lamina propria with the prevalence of eosinophilic leukocytes, inflammatory thickening of villi cylindrical epithelium and its mucous metamorphosis, pyknosis and lysis of enterocyte nuclei. In the large intestine, necrosis of the mucosa was detected, with edema, effusion of serum-cell exudate in its canal, diffusive infiltration of lymphocytes, eosinophils and plasma cells in the intestinal mucosa lamina propria. Lung tissue demonstrated parasite larvae localized in canals of the bronchi and in alveoli. These sites had diffusive hemorrhages in lung parenchyma, signs of inflammation and thickening of interstitial tissue caused by damage to vessel walls due to migration of parasite larvae. Histological changes in the liver of sheep with strongyloidiasis showed the development of granular dystrophy and necrotic changes in hepatocytes.

Parasites of domestic and wild pigeons in the south of Ukraine

Pigeons are closely related to human life and are both a source of food and object for hobbies and sports. Parasitic diseases of birds are the main reason for their growth retardation, reduced productivity and viability. The article presents the results of studying the prevalence of trichomonosis, cestodes and nematodes among the population of wild and domestic pigeons in the south of Ukraine. According to the results of the conducted researches it is established that in the south of Ukraine endoparasitoses of domestic and wild pigeons are quite widespread, and all species of this bird are carriers of Trichomonas gallinae. At the same time, the highest rate of Trichomonas infection was recorded in Columba palambus and C. livia domestica, and the overall infestation of males is higher by 4.4% compared to females. It was determined that domestic pigeons C. livia domestica were infested with trichomonosis (27.5%) and nematodes (Ascaridia columbae, 57.1%), C. palambus – trichomonosis (32.1%) and cestodes (Raillietina spp., 82.4%), Streptopelia turtur – cestodes (Raillietina spp., 12.5%) and S. decaocto – cestodes (Raillietina spp., 71.4%) and nematodes (Heterakis gallinarum, A. columbae – 33.3% and 44.4% respectively). The overall rate of infestation of pigeons with cestodes was 28.4% and the incidence in males was higher by 3.9% compared to females. It was found that the most common species among pigeon cestodes is Raillietina spp. In addition, 22.9% of pigeons are carriers of nematodes (H. gallinarum, A. columbae and Capillaria spp.). Continuous monitoring of pigeon parasites is necessary because they, in most cases, come into contact with other species of poultry and are a source of general invasion. In terms of further research, it would be promising to study the prevalence of helminthic infestation among wild migratory birds.

Differential species traits of Trichostrongylus tenuis (Nematoda, Trichostrongylidae)

Trichostrongylus tenuis Mehlin, 1846 is a helminth species that parasitizes in the gastrointestinal tract of birds and causes trichostrongylosis. Research on the differential features of the pathogen at various stages of development facilitates timely finding of the foci of infection and providing recommendations for prevention and control. In the present study, the differential species traits of male and female Trichostrongylus nematodes parasitizing in the domestic goose were examined. The nematodes were obtained in helminthological dissection of the intestine of birds kept at farms and private households in Poltava region, Ukraine. It was revealed that the morphological features of T. tenuis females that should be considered in species identification include the structural specifics of the reproductive system and the tail end. 22 metric parameters were suggested for species identification, including the female body measurements for different parts, specifics of vulva and anus location, sizes of the ovijector, sphincter, ejector and vulval area. Differences were found in the metric parameters of the lateral crests of the cuticle in female nematodes in relation to the position of crests on the parasite’s bodies. The cuticular crests were absent at 0.1 mm from the head and tail ends, and the length of crests was 9.3 mm in total. The longest and widest crests were observed in the middle of the body, the shortest were found in the anus area, and the narrowest crests were from the anterior part of esophagus to its middle. The distance between crests varied 0.2–3.0 μm, the longest at the transition of esophagus into the intestine and the shortest in area between the vulva and the anus. The metric parameters of T. tenuis eggs obtained from bird feces and in the nematode uterus differed significantly by 5 characters. The collected data on the morphological and metric parameters of females and eggs of T. tenuis can be used in species identification and understanding of the taxonomic position of that species.

The impact of certain flavourings and preservatives on the survivability of eggs of Ascaris suum and Trichuris suis

The article describes a laboratory study of nematocidal properties of flavourings with antibacterial effect against Ascaris suum (Goeze, 1782) and Trichuris suis Schrank, 1788. In the experiments, eight concentrations of food additives with antibacterial properties were used: cinnamaldehyde, benzoic acid, formic acid, linalool, citral, β-ionone. Minimum LC50 value for eggs of A. suum was observed while using cinnamaldehyde and benzoic acid – 1.62 ± 0.37% and 1.69 ± 0.14%, and for eggs of T. suis – 0.57 ± 0.03% and 1.80 ± 0.11% respectively. The lowest influence on the development of eggs of nematodes of pigs’ A. suum and T. suis was exerted by formic acid, linalool, citral and β-ionone. In eggs of A. suum and T. suis, larvae formed in 21 and 50 days even during exposure to 3% emulsions of these substances. The strongest negative impact on the eggs of parasitic nematodes was displayed by cinnamaldehyde flavouring. Further study on nematocidal properties of flavourings, as well as their mixtures, would contribute to the development of preparations which would have a strong effect on eggs and larvae of nematodes of animals and humans.

Effect of succinic acid on the organism of mice and their intestinal microbiota against the background of excessive fat consumption

Succinic acid and its salts (succinates) positively affect the oxygenation of the internal environment, stabilize the structure and functional activity of mitochondria, and normalize the ion metabolism in the cell. Separate clinical studies and experimental surveys confirmed that having low toxicity succinic acid has well-manifested antioxidant, immunostimulating, adaptogenic properties. In this study, we determined the influence of succinic acid on the organism of laboratory animals against the backround of high-fat diet: the changes in body weight, indices of the mass of the internal organs, blood parameters and the changes in the intestinal microbiota were determined. For the experiment, we formed three experimental and three control groups of male white mice. The animals of the control group received 0.5% solution of succinic acid instead of water. In the experiment, we determined that succinic acid has no effect on the intensity of growth of weight of young mice against the background of excessive fat in their diet. Excessive consumption of fat by male mice leads to mainly disorders in the functioning of the liver, excretory and the immune systems. High-fat diet of mice is accompanied by impaired hepatic function, manifested in sharp hypoproteinemia due to globulins, increase in the activity of hepatic enzymes against the background of reduced activity of alkaline phosphatase, increase in the level of bilirubin, and decrease in glucose. Excess of fat in the diet leads to malfunctioning of the excretory system, manifested in the reduced index of kidneys’ weight, high content of creatinine and reduced level of urea in the blood. Addition of succinic acid has a positive effect on the functional condition of the liver and the kidneys, especially noticeable during long-term intake. High-fat diet causes disorders in the functioning of the organs of blood circulation and immune protection, accompanied by decrease in the relative mass of the thymus and spleen, low content of hemoglobin and the number of erythrocytes, but has no significant effect on the content of other cellular elements in the blood. By the middle of the experiment, succinic acid had exacerbated these processes compared to the control, but by the end of the experiment, by contrast, these processes were alleviated. Addition of the succinic acid to high-fat diet contributed to the change in the quantitative composition of the main representatives of the obligatory microbiota (Bifidobacterium spp., Lactobacillus spp. and typical Escherichia coli) in the laboratory animals. Such changes in the intestinal microbiota may lead to such consequences as reproduction of the facultative microflora, and, thus, development of various diseases.

Impact of mineral fertilizers, growth stimulators, pH regulators, vitamins and pigment supplements on the vitality of entomopathogenic nematodes of Steinernematidae and Heterorhabditidae families

Parasites of agricultural crops cause significant losses of quality and decrease in the profitability of agricultural production. Complex measures against pests are aimed both at termination of parasites and prevention of repeated infection of plants. One of the most progressive ways of protecting plants against harmful insects is the use of entomopathogenic nematodes. This method is most expedient in the conditions of organic arable farming. The results of our study reveal the impact of the fertilizers in various concentrations on the vitality of nematode larvae (L3) of four species (Steinernema feltiae, S. kraussei, S. carpocapsae and Heterorhabditis bacteriophora) and the possibility of their combined application for the treatment of plants. Mineral fertilizers and stimulators of growth of plants in 1% concentration insignificantly reduced the vitality of larvae, allowing them to be applied at the same time. We determined the tolerance of invasive larvae to pH for S. carpocapsae equaling рН = 0.9–13.4; optimum values of рН without reliable increase in the mortality during 24 h – рН = 1.3–12.8. Increase in the vitality of larvae (L3) of entomopathogenic nematodes was studied. The survivability of the cultures of larvae increased during the use of solutions of vitamins С, В1, В6, В12. We determined the influence of 21 pigment colourings on larvae (L3), the lowest effect on the vitality of nematode larvae was exerted by pigment bases Abrikos (7.0–10.8% mortality during 24 h), Zolotoi Pesok (6.0–11.8%), Pudra Ananasa (7.7–13.4%), and complex DMAE (7.6–17.4%). The results we obtained allow development of recommendations for agriculturalists for combined use of entomopathogenic nematodes with various substances and also improving the vitality of invasive nematodes.

Ovocidal action of glutaraldehyde and benzalkonium chloride mixture on Aonchotheca bovis (Nematoda, Capillariidae) embryogenesis

Deinvasion, aimed at elimination of environmental exogenic stages of invasion agents and avoidance of their invasion to host organism, occupies an important place in the complex of sanitary and prophylactic activities against animal helminthosis diseases. Application of glutaraldehyde and benzalkonium chloride at vital activity and embryogenesis of Aonchotheca bovis (Schnyder, 1906) obtained from nematode female gonads was investigated with different concentration and exposures. Two test-cultures were used in the experiment. The first culture contained non-invasive eggs of A. bovis, the second contained invasive ones, obtained by the laboratory culturing of gonadic eggs until mobile larva maturing. It was established that glutaraldehyde and benzalkonium chloride mixture has a deinvasive capacity against A. bovis eggs, parasitizing on sheep. Ovocidal efficiency indexes appeared higher with use of the test culture against the non-invasive capillaria eggs’ test-culture. So, the high level of ovocidal efficiency of glutaraldehyde and benzalkonium chloride mixture against non-invasive A. bovis eggs culture was established at the concentration of 0.5% and exposure of 10–60 min (93.6–100.0%), and against the invasive A. bovis egg culture – at the concentration of 0.5% and exposure of 30 and 60 min (90.3–94.6%) and 1.0% at all exposures (100.0%). Ovocidal activity of the examined mixture was accompanied by specific morphological changes of nematode eggs structure. Destruction of the egg envelope, embryo loosening and decay and its dissolution were observed. Such changes are proved by metric indexes of width and length of capillaria eggs, envelope thickness and cap length, indicating the violation of embryogenesis of A. bovis. Thus, glutaraldehyde and benzalkonium chloride mixture of 1.0% concentration is a promising deinvasive agent suitable for effective fight against and prophylaxis of sheep-breeding nematodosis.