The study presents new data on the structural and functional organization of the mesonephros of the grayling Thymallus thymallus (Linnaeus, 1758). Adult grayling were sampled in the middle course of the Unya River, a tributary of the Pechora River (Komi Republic, Russia). The mesonephros of the grayling, as of other freshwater fishes, is composed by nephrons, blood vessels and hematopoietic tissue forming the renal interstice. In the interstice, сells with a radial vesicle array and chloride cells were discovered; the latter were mostly localized near the renal tubules. The degree of the interstice development in the mesonephros of the grayling was determined. New data on the ultrastructure of leukocytes, cells with a radial vesicle array, chloride cells, and nephron segments were obtained. A lack of mesangial cells, a small number of podocytes, and a thin basement membrane were observed on the sections of a renal corpuscle, being characteristic features of the ultrathin organization of the mesonephros in freshwater members of Salmoniformes and Esociformes. In the grayling’s nephrons, no neck segment was found, which was reported earlier for several species, including mammals. On the sections of proximal tubules, the ciliated cells were rare, and large amounts of the tubular-vesicular network in the zone of endocytosis of the type II epithelial cells were observed. On the sections of distal tubules, short blade-shaped cytoplasmic processes, with large numbers of invaginations of cytoplasmic membrane, were found. On the basis of the distinctive ultrastructure features mentioned above, the inference that grayling show the cytological markers of adaptation to euryhalinity was made. Thus, the results contribute to the knowledge of mesonephros development in fishes during their life history. From the species protection standpoint, our study provides baseline data on a WBC differential in the mesonephros as well as superoxide dismutase, catalase, glutathione S-transferase, and ethoxyresorufin-O-deethylase activities, which can be used in further studies addressing the health status of grayling populations.
The article presents the study results of the chemical composition of Cyprinidae and Percidae skeletal muscles from the Sot', Vopsha and Kast' rivers in the territory of the Yaroslavsky State Nature Reserve. The fish were ascertained for sex, stage of gonad maturity, and age. The total amount of water, dry matter, total lipids, protein, minerals, and nitrogen-free extractives (NFE) were determined in their muscle tissues. The study revealed significant differences in the content of final metabolic products in the muscles of individuals of the same species living in different rivers, which may be connected to the difference in food supply or with characteristics of hydrochemical composition of the reservoirs under study. It has been stated that the chemical composition of muscle tissues depends on the trophic status of aquatic organisms, their sex and age. On average, in the rivers the carpal skeletal muscles were superior to the perch muscular tissue in terms of total lipid content, but inferior to the amount of protein, ash, and NFE. As it was revealed, the female muscles contained more protein and fat, than muscles of males and juveniles. Reduction of dry matter and fat in the muscle tissues of roach, sabrefish and rudd (aged 4 to 5) can be associated with attaining puberty in fish. With age, a decrease of water was observed in Cyprinidae and Percidae muscles due to accumulation of dry matter. With ageing of the studied fish in their muscle tissues was found both the increased and decreased concentration of protein, total lipids, mineral substances and NFE. From the data obtained it can be inferred that the fish population of the rivers flowing through the territory of the Yaroslavsky State Nature Reserve exist in relatively favorable conditions.
The article gives the results of the study of the fatness and chemical composition of skeletal muscles of underyearling Esox lucius L., grown in different fish-farms of the Yaroslavl and Volgograd regions. The fish was measured, weighed; Foultin’s fatness coefficient was calculated. The amount of water, dry matter, fat, protein, minerals and nitrogen-free extractives were determined in the muscle tissue of the test specimens. In autumn yearlings of both fish farms approach 100 g weight, average body length being 19-21 cm. At the age 2+ pike juveniles of the Volgograd fish farm (sole trader - “Head of the Peasant farm Lozina Ya.V.”) overtake those grown in “Stimul” fish farm, Ltd. in Yaroslavl region in size and mass. However, Fultin’s condition factor in individuals of the Yaroslavl region was significantly higher than in the young from Ya. V. Lozina’s fish farm. There were no statistically significant differences between the water content, protein content, fat content, and nitrogen-free extractives in the skeletal muscles of pike underyearlings from different enterprises. Though, there was registered a significant increase in the amount of mineral substances in the muscle tissue of pike underyearlings from “Stimul”, Ltd ( p < 0,05). On average, muscular tissue of pike underyearlings from “Stimul”, Ltd was larger than that of Ya.V. Lozina’s fish farm in terms of nutrient content and energy value. The study results showed that fatness and chemical composition of the muscle tissue of pike yearlings is more influenced by the sufficient food supply than hydrochemical conditions of the pond.
We researched the influence of the additive Chlorella cultivated in a closed bioreactor under the influence of an electrostatistic field, on the biochemical and hematological parameters of blood in different age groups of cattle. The experiment was conducted on two groups of three month old heifers and two groups of lactating cows in the 7th month of lactation, with 15 individuals in each group; all animals in the groups were given the basic diet. During the 120-day experiment, the experimental group of heifers was fed on a suspension of Chlorella cultivated with the technology using an electrostatic field, in the following amounts: 1–30th day – 1.51 g, 31–60th day – 1.82 g, 61–90th day – 2.01 g, 91–120th day – 2.28 g of dry substance per individual daily; the group of lactating cows during 60 days was given the Chlorella additive to the amount of 6 g of dry substance per individual per day. Over the following 30 days the heifers and lactating cows were kept under observation to determine the “aftereffects” of the Chlorella suspension fodder additive. On the first day of the experiment and after every 30 days, blood was drawn from the animals’ jugular veins for determination of the biochemical and hematological parameters of the blood During the experiment, the experimental groups of heifers and lactating cows were observed to have a strengthened antioxidant system due to increase in the activity of superoxide dismutase and catalase, and also to have a strengthened hematopoietic function and intensified metabolic and redox processes. Due to the stimulating effect of the suspension of Chlorella cultivated using the intense technology involving using an electrostatic field on the erythro- and leukopoiesis of different age groups of the cattle, we determined a strengthening of the cellular element of the animals’ immune system. During the following 30 days, the heifers and lactating cows of the experimental groups were observed to exhibit “aftereffects” of the Chlorella suspension additive, namely increases in the values of biochemical, hematological and morphological indicators of the blood in comparison with these indicators for the animals in the control groups. As a result, we concluded that feeding different age groups of cattle with suspension of Chlorella cultivated in the conditions of a closed bioreactor under the influence of an electrostatic field, in the dosage of 155 ml per kg of dry substance of the animals’ diet, contributes to the strengthening of non-specific defence of their organism, forming a potential for increasing the productive indicators and maintenance of the livestock.
Аннотация В статье представлены результаты применения йодсодержащих добавок в кормлении лактирующих коров. Сделано предположение, что включение в рацион животных микрокорма «Прост», содержащего органическую форму йода, способствует усилению гормонообразующей функции щитовидной железы, за счет чего происходит увеличение показателей молочной продуктивности коров. Установлена целесообразность применения этой добавки в кормлении животных по результатам расчета экономической эффективности. Ключевые слова: щитовидная железа, дефицит йода, гормоны, лактирующие коровы, молочная продуктивность.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.