Use of hulless oats in feeding of pedigree 1+ carp as an effective method for ensuringthe physiological needs of fish

Purpose. To study the effect of addition of hulless oats during the growing period on the qualitative and quantitative indicators of replacement-brood stock of carp. Methodology. The replacement-brood stock of Lubin intra-breed type of Ukrainian scaly carp strain, which were kept in ponds of State Enterprise Experimental Fish Farm of Lviv Research Station of the Institute of Fisheries of the National Academy of Agrarian Sciences of Ukraine (IFNAASU) was used for the study. The stocking density was 1000 fish/ha. The experiment was based on four experimental groups. Carps of the first experimental group were fed during the entire growing period with a feed mixture with the addition of hulles oats in the amount of 10 %, while carps of the second group were fed with a feed with the addition of 30 % of hulless oats. The third experimental group received a feed mixture in June – July, and hulless oats in August. The control group of carp was fed with the feed mixture throughout the entire growing period. The stocking density of fish was 1000 fish/ha. Piscicultural studies were conducted in accordance with current methods. Sampling of water for chemical analysis and its processing in the laboratory was carried out according to O. Alokin according to the Standard of the Ministry of Agrarian Policy of Ukraine. Haemoglobin content was determined by the haemoglobin-cyanide method. Blood erythrocytes were counted in a Goryaev chamber. Abundance and weight of natural feeds in ponds were determined according to I.A. Kyseliov, V.I. Zhadin. Zooplankton biomass was determined using tables of individual weights of F.D. Mordukhai-Boltovskoi. Analytical processing of the material was performed using MS Excel. The criteria for the analysis of indicators were their mean (M) and mean deviation (m). Findings. Peculiarities of growth, development of carp and efficiency of feed usage with the addition of hulless oats on the background of similar satisfactory growing conditions were studied. It was found that additional feeding of carp with hulless oats at an amount of 30% was effective. In particular, its addition resulted in an increase in individual weight by 31.1% and survival rate by 2.33%. Studies of the physiological functions of the body of experimental fish during the growing period after adding the hulless oats into the main diet provided an opportunity to recommend its use in the feeding process of age–1+carp in order to increase fish productivity. Originality. The advisability of using hulless oats in the feeding of replacement-brood stock of juvenile carp was studied in Ukraine for the first time. The analysis of productive, physiological and economic indicators has been carried out. Practical value. The results of a comprehensive assessment of piscicultura; and biological parameters provide recommendations for the use of hulless oats in the feeding of replacement-brood stock of juvenile carp. Key words: carp, replacement-brood juvenile stock, feed, feed additives, normalized feeding, physiological needs, fish productivity, feed costs, natural food supply.

Genomic basis of fishing-associated selection varies with population density

Fisheries induce one of the strongest anthropogenic selective pressures on natural populations, but the genetic effects of fishing remain unclear. Crucially, we lack knowledge of how capture-associated selection and its interaction with reductions in population density caused by fishing can potentially shift which genes are under selection. Using experimental fish reared at two densities and repeatedly harvested by simulated trawling, we show consistent phenotypic selection on growth, metabolism, and social behavior regardless of density. However, the specific genes under selection—mainly related to brain function and neurogenesis—varied with the population density. This interaction between direct fishing selection and density could fundamentally alter the genomic responses to harvest. The evolutionary consequences of fishing are therefore likely context dependent, possibly varying as exploited populations decline. These results highlight the need to consider environmental factors when predicting effects of human-induced selection and evolution.

Toxic Effect of Monocrotophos on Various Blood Parameters in Edible Freshwater Fish Oreochromis Mossambicus (Tilapia)

In modern agriculture, farmers are using the authenticity of pesticides for agricultural activities. Water bodies are often polluted with various harmfull chemical substances. Fishes are very important for human nourishment. In this study, the effect of Pesticide monocrotophos on various hematological parameters such as RBC, WBC, and Hemoglobin was observed in freshwater fish Oreochromis mossambicus. The fish were exposed to various sub-lethal concentrations (1/10, 1/20, and 1/30) of Monocrotophos for 10, 20, and 30 days. The blood samples were analyzed at the end of every exposure period. Increased count of WBC observed in Lower Sub lethal concentration (21.25, 21.76, 22.01), Medium Sub-lethal concentration (21.69, 22.48, 22.89), and Higher Sub lethal concentration (22.47, 23.54, 23.69) of monocrotophos at various monocrotophos exposure periods on experimental fish Oreochromis mossambicus. Decreased count of RBC observed in Lower Sub-lethal concentration (3.58,3.21,3.08), Medium Sub-lethal concentration (2.97,2.35,2.19) and Higher Sub-lethal concentration (2.41,2.16,2.02) and decreased level of Hemoglobin were observed in Lower Sub-lethal concentration (21.25,21.76,22.01), Medium Sub-lethal concentration (21.69,22.48,22.89) and Higher Sub-lethal concentration (22.47,23.54,23.69) of monocrotophos at various exposure period on fish Oreochromis mossambicus. The 1/10 sub-lethal concentration of monocrotophos showed a high level of variation on 30th-day exposure. Reduction of RBC indicates hemolysis in fish and increased WBC count has been considered to be an adaptation of animals to meet stressful conditions. In the present study, it was found that the effect of monocrotophos alters the activity of various blood parameters in freshwater fish Oreochromis mossambicus. Therefore, the experiment is an attempt to study the toxicity of the pesticide Monocrotophos concerning blood parameters of freshwater fish Oreochromis mossambicus. It is concluded from this study that exposure to Monocrotophos affects the hematological parameters of fish.

Characteristics of biochemical indicators of sperm production of carp males while using naked oats in the nutrition process during pre-sprawning period

In the research there have been used males of the Nyvka intra-breed type of the Ukrainian scaly carp breed, which were kept during the pre-spawning period in the pond conditions of the State Enterprise “Experimental fish farm Nyvka” within the Institute of Fisheries of the National Academy of Agrarian Sciences of Ukraine (IFNAASU). The carps were divided into 3 groups. The first group (Experiment I) was fed 100 % naked oats, the second (Experiment II) – 30 %, the control group of fish (Control) was fed a grain mixture. The quality of sexual products of male carp was assessed by determining the effect of adding naked oats to their diet during the pre-spawning period. Indicators of sperm motility and fertilizing ability, content of γ-, β- and α-globulins, albumin, prealbumin, and physiological characteristics of ejaculates of respiratory and regenerative capacity, activity of enzymes of respiratory chain of mitochondria (CHO and SDG) were studied. Given the increased productivity of fish sperm, in particular the increase in the number of sperm with rectilinear motion, decrease in the number of inanimate sperm and changes in the protein formula of germ cells, it is advisable to add naked oats to the main diet in the amount of 30 %.

Banana (Musa paradisiaca) Midrib Extract as a Curative Agent of Motile Aeromonad Septicemia in Giant Gourami (Osphronemus gouramy)

This study aimed to evaluate the effects of banana (Musa paradisiaca) midrib extract supplementation as preventive and curative treatments of motile aeromonad septicemia (MAS) on giant gourami (Osphronemus gouramy). Disc diffusion assay was conducted to evaluate antibacterial activity of banana midrib extract against Aeromonas hydrophila. The most effective dose was used for subsequent tests. Experimental fish were categorized into five groups: negative control; positive control; and preventive, curative, and controlling treatments. Except negative control, all groups were challenged by A. hydrophila at a density of 107 CFU mL−1 (0.1 mL per fish). Preventive, curative, and controlling treatment groups were administered the banana midrib extract-enriched diet (3%), whereas positive and negative controls were not treated with banana midrib extract. The results showed that banana midrib extract inhibited A. hydrophila activity in giant gourami, demonstrated by lower A. hydrophila numbers in preventive, curative, and controlling treatments than those in the positive control. After the challenge test in the fish treated with banana midrib extract, immunity parameters were better than those of the positive control. Banana midrib extract was highly effective as a curative agent against MAS in giant gourami based on the highest survival of the experimental fish compared with other treatments.

Innovation in the creation of high quality carp crosses

The tendency of increasing the use of aquatic products in human nutrition, as the most valuable suppliers of polyunsaturated fatty acids omega-3 and omega-6, has been substantiated. The main directions in the development of high-intensity technologies for the production of fish products in the Republic of Belarus are given. A generalized analysis of the situation on conducting selection and breeding work with carp breeds of Belarusian, foreign selection and Amur carp of the Khanka population is carried out. The article presents innovative trends in fish farming in Belarus for obtaining highly productive commercial crosses with improved commercial characteristics and the results of morphological studies of three-year-old mirror crosses obtained on the basis of crossing of female imported breeds and male carp of Belarusian selection. The separate stages of carrying out fish-breeding techniques and preventive measures with the aim of growing high-quality fish products in OJSC "Experimental fish farm "Selets" are considered.

Effect of different salinities on the susceptibility of striped catfish (Pangasianodon hy-pophthalmus) to Aeromonas hydrophila bacteria causing hemorrhagic disease

This study was conducted to determine the effect of different salinities on striped catfish (Pangasianodon hypophthalmus) susceptibility to hemorrhagic disease causing by Aeromonas hydrophila bacteria. The experiment was set up in plastic tanks at various salinities (0, 3, 5, 8, 11 and 14‰). Experimental fish (about 25 ± 0.8g/fish) were challenged with A. hydrophila bacteria by intramuscular injection. After infection, the mortality and disease signs were recorded for 14 days. At the same time, bacteria re-isolation and re-identification were carried out with infected fish samples that displayed signs of lethargy, disorientation, hemorrhagic in anal, peritoneal sinus and spleen. Recorded cumulative mortality after 14 days was 86.7% at salinity 0‰ and 8.3% and 11.7% at salinities 11 and 14‰, respectively. At higher salinity, striped catfish is less susceptible to A. hydrophila bacteria than at lower salinities.

Studying Cholesterol and Triglyceride Levels in Some Types of Fish in Salah Al-Din Governorate

The study included seven common types of fish in the Iraqi local market in Salah al-Din Governorate / Tikrit, which are (Carasobarbus luteus, Alburnus mossulensis, Cyprinion kais, Chondrostoma regium, Barbus barbulus, Barbus belayewi, Barbus subquincunciatus). The study of cholesterol and triglycerides of these types of fish showed that the cholesterol levels in the experimental fish were (104.55-9.56 -6.37-9.56 -14.88-51.03-15.94) mg/100 g in the mentioned fish, respectively, and the highest level of cholesterol was in the Carasobarbus luteus fish and it reached 104.55 mg /100gm, and the lowest level in Cyprinion kais is 6.37mg/100gm. The study stated the levels of triglycerides are (990 -348 -993.5 -665.9 -703.5 -1355.2-882.2) mg/kg for fish (Carasobarbus luteus, Alburnus mossulensis, Cyprinion kais, Chondrostoma regium, Barbus barbulus, Barbus belayewi, Barbus subquincunciatus) respectively. The highest level of triglycerides is 1355.2 mg/kg. kg in Barbus belayewi fish and the lowest level in Alburnus mossulensis 348 mg/kg.

Characterization and Expression Profiling of Glutathione Peroxidase 1 gene (GPX1) and Activity of GPX in Onychostoma macrolepis suffered from Thermal Stress

In this study, full-length cDNA of glutathione peroxidases 1 (GPX1) of Onychostoma macrolepis was cloned by RACE, and expression of GPX1 and activity of GPX in O. macrolepis suffered from heat stress were analyzed. Compared with the control group (24°C), the experimental fish were stressed for 0, 1, 3, 6, 12, 24, and 48 hours at the heated water (30°C). Liver had highest level and response speed in GPX1 expression among various tissues after heat stress, indicated that liver was the highest sensitive tissue to heat stress. When the water was raised to the heating temperature (30°C), the GPX activity decreased in fish serum, and the consumption of GPX eliminated the increase of ROS caused by heat stress within 3h. However, after 6h and 12h stress at 30°C, GPX activity was significantly higher than that at 0h (P<0.05), which is due to the rapid response of GPX to heat stress. In summary, fish showed a transient stress response and was acclimated to the new temperature after 24 h according to the overall expression of the GPX1 and the serum GPX activity, and both GPX1 and GPX play crucial roles in this process.

Evaluation of the Energy Budget of the Fish Cyprinus Carpio in Acid Waters

The present study was focused on the influence of acid waters on the energy budget of the fish Cyprinus carpio. The experimental fish were tested in the experimental media (pH 5.0, 5.8, 6.6, and control 7.2) for 21 days for the bioenergetics evaluation. The fishes were fed by the fresh beef liver. The pH was upheld vigilantly throughout the investigation, after the experimental period, the results revealed the declined rates of food consumption (69.75 J/g/day), absorption (96.28 (J/g/day), conversion ( -30.76 Rate of energy conversion (J/g/day), and the hyper-metabolic rate (5.09 Energy metabolized KJ/animal) was observed in the fishes exposed to low pH 5.0, 5.8, and 6.6 respectively.