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Effect of different weaning time on the growth and survival ofCommon carp (Cyprinus carpio L.) larvae
55-59Views:744Within our experiment, we studied the combined effect of live food application and feed training on the production parameters of carp larvae. In addition, we examined whether there is a difference in the growth rate and survival rate of the specimens of Szeged mirror landrace reared in similar stocking density but with different treatments.
Specimens of Szeged mirror landrace from induced propagation were placed into 12 pieces of 40-liter aquaria. For the 4 different treatments, (K, A3, A6, A9), live food (Artemia salina) was fed, as well as feed training was applied.
We also sought to find an answer as to how our feeding and rearing conditions can affect the production parameters of common carp fries and what impact these conditions may have on their survival rates. At the end of the 2-week experiment we determined the individual weight gain of the carp fries, their survival rate and the biomass growth. The purpose of the study is to examine the optimum timing of shifting from live food to feed for carp larvae.
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Utilization of live feeds in fish larviculture: A review
103-116Views:135This review examines the significance of live feeds in commercial aquaculture industry for production of fish and shrimp larvae, along with various challenges and prospects. Live feeds are an essential food source in larviculture, especially for marine fish, which depend on them for nutrition during the initial days of exogenous feeding. They are palatable, highly digestible, and their movement stimulates natural hunting and foraging instincts, promoting better development, lowering captivity stress, and increasing survival rates. Artemia is the most commonly used live feed in larviculture; however, it has low levels of omega-3 HUFA. Copepods are the most nutritionally rich live feed, containing high levels of DHA and EPA. Despite these benefits, they are less frequently used in larviculture due to technical challenges associated with large-scale cultivation at high densities. The use of live feed is labour-intensive and costly. The feeding period for fish larvae can be shortened using a co-feeding strategy. Microalgae rich in DHA have been utilized to enrich live feeds. Further research is needed to determine the most effective approach to significantly reduce the weaning time of fish larvae from live feed. This will lead to gradual and eventual complete replacement of life feed in the near future.
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Awareness and adoption of a nurse sow management system among small-scale pig farmers in Nakuru County, Kenya
113-120Views:330This study aimed to assess the level of awareness and adoption of nurse sow management strategies among small-scale pig farmers in Nakuru County, Kenya. The research included a survey of pig farmers who visited the Nakuru Agricultural Show in July 2023. A total of 139 farmers were interviewed within 5 days of the show. The corresponding author interviewed the respondents in a face-to-face engagement, where questions on nurse sow management were initially drafted in English and translated into Kiswahili, i.e. the second language in Kenya. The obtained results indicated that farmers came from two main regions of the county: the northern part (54.7%, 76/139) and the southern part (45.3%, 63/139). Levels of awareness and adoption were insignificant between the two groups (χ2, p<0.05). A major obstacle to the adoption of this strategy was identified as feed challenge at 77.7%; (108/139) and market issue at 59.7%; (83/139). This study identified important aspects and limitations that should be considered when developing sustainable productivity development strategies for Kenyan pig farmers. To assist the sustainable growth of small-scale pig production, the authors suggest government measures that shield farmers against exploitation of feed and marketing components, as well as advocating for effective breeding to increase live born.
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Preliminary results on Siberian sterlet (Acipenser ruthenus marsiglii) fries rearing under intensive conditions
27-31Views:218In our experiments production performances of Siberian sterlet were tested under intensive tank conditions. During the 25 days long experiment effectiveness of weaning to artificial diet of the fish was investigated. Production performances of fish fed on exclusively dry diet from the beginnings were lower than the other two groups. Between the values of sterlets fed on live food also then suddenly vs. continuously were weaned to dry diet there were no significant differences. Based on our results live food feeding could be suggested for the Siberian sterlet larvae for some days but the method of the weaning to dry diet has no significant influence to the production performances.
In 21 days long experiment four different feeding frequencies were tested in Siberian sterlet (~13 g) fingerlings. Dry feed was offered for the fish continuously, 2, 3 and 4 times per day. There were no significant differences between the values of the four treatments. Based on our results there is no high influence of feeding frequency in case of this size group of Siberian sterlet.
During the nursing in two different size groups of Siberian sterlet the optimal daily amounts of feed were aimed to determine. In case of growth values of the group fed at 7% of the total biomass were higher than the other two groups (3 and 5%). Feeding performances of fish fed at 5% were significantly better than fish fed at 7%. Based on our results for ~20 g size of the subspecies at least 5% of total body weight could be suggested.
In case of ~150 g size of the fish the production performances of fish fed at 1% were lower than the other two groups (2 and 3%). Between the values of stocks fed at 2 and 3% there were no significant differences. Based on these results 2% of total body weight of dry feed could be suggested for the Siberian sterlet with ~150 g body weight.
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Climatic water balance in Hamelmalo, Eritrea
69-76Views:383Agricultural production is an important sector for peoples to live, but it is highly affected by climate change. To have a good production we need to understand the climatic parameters which adversely affect production. Hamelmalo, which is located in the semi-arid area of Eritrea, is vulnerable to climate change and this is realised in the total production loss. Nevertheless, there is no concrete reference about the climate of the region due to lack of data for a long time. Changes in precipitation (P), evapotranspiration (ET) and, implicitly, in the climatic water balance (CWB), are imminent effects of climate change. However, changes in the CWB, as a response to changes in P and ET, have not yet been analysed thoroughly enough in many parts of the world, including Eritrea. This study also explores the changes of the CWB in the Hamelmalo region, based on a wide range of climatic data (P, relative air humidity and evaporation pan necessary for computing potential evapotranspiration (PET) with the pan evaporation method) recorded at Hamelmalo from 2015-2019. This analysis shows that the annual cumulative CWB for Hamelmalo is negative in 67% of the years. The dry season without precipitation leads to negative CWB and the change in CWB only starts from the raining or crop season. Based on this recent study, 2015 had the highest PET and lowest P, and this resulted in the lowest CWB in the investigated period. Opposite to this, 2019 had lower PET and highest P, which led to the highest CWB. However, the monthly values of CWB did not correlate with the annual P or ET. On the base of our study, it can be concluded that PET and P were very variable in the investigated years and P was the most influential elements of CWB.
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Fresh fruit purchase analysis in the town’s circle in the Nothern Great Plain Region
101-106Views:200In my research I aimed to examine the previous theories about consumer habits and behaviors as well as the preference of different fruit species in the Northern Great Plain Region. Furthermore, I also wanted to know if there are any correlations between the product atributes that influence fruit consumption and different ages, genders and income categories.
The importance of my research field is reflected in the fact that issues in connection with foodstuffs, healty diet and food safety have been highly emphasized recently.
I belive in order to live longer we need to pursue healthy diet that is rich in fruits and vegetables. It seems, however, not every can follow this lifestyle in their every day diet since most people prefer junk food that contains harmful ingridients.
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A review on fish in vitro digestion studies
55-63Views:43(1) Background: In vitro experiments in fish have been developed to search for dietary substitutes of fish meal in aquafeeds by measuring the digestibility of various feedstuffs by simply simulating the conditions of the stomach or portions of the digestive tract. In vitro digestion studies involving mainly commercial fish species have been conducted to determine the digestibility of conventional and alternative ingredients in fish diets using diverse digestion models. However, there remains a significant knowledge gap, particularly regarding the enzyme functionality, digestion mechanisms in many fish species, and the factors influencing enzymatic activity. This review article is focused on the importance of the use of different enzyme sources in the in vitro digestion model to predict protein hydrolysis.;(2) Methods: For this review, a comprehensive analysis of articles was conducted to gain insights into diverse enzyme interactions and feed evaluation assessments, from the nutritional science and biotechnology sector.; (3) Results: A total of 36 peer-review papers, which include original, and review articles were selected.; (4) Conclusions: In vitro digestion studies offer a valuable tool for evaluating the digestibility of conventional and alternative feed ingredients, helping to identify sustainable dietary substitutes for fish meal while reducing dependence on live animal trials.
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New Possibilities of Brown Bullhead (Ictalurus nebulosus) Farming
55-57Views:166The brown bullhead (Ictalurus nebulosus) has been settled in Europe at the end of Century XIX from North America. In Hungary it has been brought in 1902. The naturalization of this species was successful because the brown bullhead found adequate conditions for its life and reproduction in Hungary. But it was unsuccessful because lost its excellent growth.
In inland water habitats-and that’s why also fishponds-extraordinarily multiplied, but because of its slight growth this species is undesirable for the native farmers. The brown bullhead is concurrent for domestic fish species, on the other hand its weight not more than 150-200 g. Occasionally it was exterminated, but multiplied again and again.
In 1999 we placed out black bullhead offspring in a pool of a new intensive fish farm, in order to breed at least 300-350 g weight for the customers. The accidental trial was surprisingly successful. Consequently, the black bullhead prefers the artificial food, and produces excellent growth parameters and specific feed-live weight conversation ratio.
On the 20th of September 1999 there was placed 23 300 pieces of brown bullhead offspring, with 28 g average weight and 625 kg gross weight. When we sold them on the 22nd of February 2000, the gross weight was 3387 and the live weight gain was 2735 kg. The gross weight of the feed was 3041,8 kg, and the feed-live weight conversation ratio was 1,11 kg/kg.
Because of this successful trial the managers of the farm wanted to start systematic experiments to work out the details of the intensive farming of brown bullhead. We undertook to help to find the right place of the species in the Hungarian fish processing because of the increasing native and foreign demand. -
Assessment of backfat thickness and its relationship with reproductive performance of sows – preliminary findings
25-30Views:408Backfat thickness (BFT) is an important trait that influences reproductive performance in sows. This study investigated the relationship between sow BFT at farrowing and the number of live born (LB), stillborn (SB), and Mummies (Ms) in different parities (P) (1, 2, 3, 4, 5, 6, 7 and 8). Backfat thickness was measured at point P2 (BFT at the last rib, at the junction of the thoracic and lumbar vertebrae 3–5 cm from the midline of the spine (mm). In total, 216 sows were measured on day 109 of gestation (when they entered farrowing). Descriptive statistics showed that the mean BFT was 14.55 mm SEM 0.171 SD 2.576. Parity had a significant effect on BFT, with a Kruskal-Wallis chi-squared value of 22.728 (df = 7, p = 0.002). Post-hoc pairwise comparisons using Dunn's test in R revealed that P1 exhibited a significantly higher BFT than P3 (p = 0.001) and P4 (p = 0.025). Spearman’s correlation coefficient indicated a very weak negative relationship between BFT and LB, whereas there was a strong relationship between BFT and SB and Ms. However, the correlations were not significant p>0.05. This finding suggests that assessing the BFT before farrowing is a helpful tool for guiding sow management and pig production. Additionally, these findings offer data that can be used to inform culling policies.
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Development alternatives of rural economy
187-191Views:162Environmental, natural, social and economic processes undergoing both in Europe and in the world predict such a 21st century that is characterised by increasing resource-crisis from both economic and ecological aspects. Therefore, it is very important for Hungary to see what happens to its natural resources, epecially to its agricultural land, water reserves as well as the biodiversity of the local unique flora and fauna. One of the most significant issues of the rural areas of Hungary is whether we can preserve the natural habitats and the various biodiversity of the related species, the favourable biological background of agriculture. In addition, whether we are able to provide high quality food for the country as well as for the broader reagion, whether we are able to produce energy from the resources available as well as to provide sufficient opportunities for the population to live and work. These can be considered as the most significant issuesof the coming decades which determine the strategy of the Hungarian rural economies in long term.