Search

Published After
Published Before

Search Results

  • Heat treated feeds in turkey feeding
    19-22
    Views:
    93

    The main aim of our study was to determine the effect of expanded and pelleted feeds, as well as the only pelleted feed based on wheat and corn, on the production of turkeys. In May 2006,, a fattening experiment on turkeys was started on the starter farm of Habar Ltd in Szarvas, owned by the Gallicoop Corporation. 17 day old male turkeys were involved in the fattening experiment. The experiment lasted 117 days. At that time, theanimals were 134 days old. After the experiment was completed, they were slaughtered. The following parameters were examined: growth, feed conversion ratio, carcass traits. Turkey feed were produced separately at different times. Similarly to the standard method of turkey fattening, 8 phases feeding was carried out. The fattening experiment was adjusted on male turkeys in 4×12×6 grouping (4 treatments: expanded and pelleted, and only pelleted corn and wheat feed; 12 repeats: number of pens/treatments; 6 birds/pen) 6-6 turkeys from 12 pens per each treatments were measured individually from the 17th day (starter) and at the time of each following feeding changes and mortality. The average of the group was calculated. The average daily weight gain, proportion of the given feed per pen, feeding changes and mortality were determined. The average daily feed intake and the feed conversion ratio were calculated.

  • The effects of bioactive feed additives for the production parameters of common carp (Cyprinus carpio) fingerlings in intensive recirculating system
    35-41
    Views:
    213

    For the appropriate quantity and quality of fish meat the pond farmers need to use up to date nutrition and feeding technologies. Recently the intensification of the carp production is stepping up with the availability the proper quality of the artificial feeds. The using of different feed additives make a better feed conservation ratio, faster growing rates and more uniform stocks.

    In our experiment what is made with common carp (duration of the experiment was 8 weeks long) we compared two different kinds of feed additives in different doses. One of them contains only natural mineral elements and the other additive is a natural origin probiotics. Both additives were used in the quantity of 0.5, 1 and 2% of the total feed. By the result of the 8 weeks experiment it could be said, that the using of the humic acid based mineral elements feed additive. Makes a better FCR comparing with the control stock, but was not as good as the using of the probiotics. At the humic acid treatments the more doses, the better FCR value, but at the probiotics it wasn’t true. The 0.5% probiotic treatment gave the best result. It is concluded that the using of the probiotic feed additives always gave a better performance of the fishes (average weight, biomass, FCR) than the humic acid treatments. The using of the feed additives hasn’t got an influence for the survival rate of the carps.

  • Effect of feeds with different crude fiber content on the performance of meat goose
    5-8
    Views:
    309

    In the last 50 years, poultry meat production has increased dynamically. The role of crude fiber content in feed is unclear based on a small amount of literature about goose feeding.

    The aim of theis experiment was to determine how various crude fiber content (55; 60; 65g crude fiber/kg feed) influences the performance of meat geese in the second phase of the rearing period. 150 goslings (3 treatments, 5 cages/treatment, 10 birds/cage) were included in the test. The experiment started and finished at the age of 21st and 63rd  day, respectively.

    The obtained results suggest that various crude fiber content did not influence the performance of meat geese significantly; however, a feed of 55g crude fiber/kg resulted in better fattening results (final body weight, body weight gain, specific feed protein and energy conversion rate). In addition, compound feed of 65g crude fiber/kg proved more favourable with respect to cost-efficiency. Based on the obtained results so far, further models and farm experiments are required.

  • Comparison of supplier quality assurance methods for compound feed manufacturing from efficiency, product consistency and economical point of view
    29-34
    Views:
    87

    Feed manufacturing and human food production are the main routes of use for agricultural products. The food industryparticularly has intensively implemented the recent quality management principles and developed systems that facilitate the continuous improvement and efficiency of the industrial production. Feed production has taken similar approaches however the intensity of deployment at the manufacturer and the rollout towards its supply chain has shown slower progress. The methods, that the feed manufacturer manages the supplier chain of mainly primer agricultural products according to, have a certain impact on the efficiency of the inbound operations, feed product quality and its consistency as well as on other resources. These methods have been built on sound quality management principles that are stated not only in quality standards but also in relevant regulations. Current study addresses the questions related to the link between supply chain quality management and feed product. The objective of the frontier research was to highlight the  theoretical possibilities and benefits of the robust design methodimplemented into animal feed manufacturing dealing with highly variable ingredients. 

  • A growth model to predict body weight and body composition of broilers
    17-24
    Views:
    331

    Models predicting the nutrient partitioning and animal performance have been developed for decades. Nowadays, growth models are used in practical animal nutrition, and they have particular importance in precision livestock farming. The aim of the present study was to introduce a broiler model and to provide examples on model application. The model predicts protein and fat deposition as well as the body weight of an individual broiler chicken from digestible nutrient intake over time. Feed intake (FI) and the digestible nutrient content of the feed are inputs as well as some animal factors like: initial BW, feed intake at 1 and 2 kg of BW, precocity and mean protein deposition. The protein and energy metabolism is represented as in the classical nutrient partitioning models. The protein deposition (PD) is driven by digestible amino acid supply and is under “genetic control”, the so-called potential PD limits the actual PD if protein is oversupplied.

    The authors discuss how the model can be used to simulate the animal response upon different scenarios. Examples are given to show that the diet might be limiting if some animal trait is changed. Applicability of the model has shown through running the model by using different feed strategies (three- vs five-phase-feeding) and variations with animal factors. In conclusion, growth models are useful tools to support decision making for defining the most suitable feeds used in a broiler farm. The model presented in this paper shows a high sensibility and flexibility to test different scenarios. By challenging the model with different inputs, the animal response in terms of changes in body weight and feed conversion can be understood more by studying the shift in deposition of chemical constituents. The examples provided in the present paper shows the benefit of using mathematical models and their applicability in precision nutrition. It can be concluded that the growth model helps to apply “from desired feed to desired food” concept.

  • The examination of roe deer feeding on agricultural and woody habitats in winter
    23-26
    Views:
    105

    sorting because the micro organisms, which help the digestion of high fibre plants, are missing in his stomack, that is why they are mostly called „concentrate selectors” (Hoffmann, 1985, 1988, 1989).
    These animals should mostly eat easily digestable plants with high nutrition level (pulses, buds, sprouts and flowers), and they are able to do this sorting because of their mouth size. In winter there is a lack of these plants, so the high selectivity occurs only when the feed is in abbundance.
    Examining the amount and quality of vegetation available on the habitat of roe deer we can identify the species which can satisfy their feed demand. It is known, that roe deer as other large ruminants, from the plant abundance prefer certain plants and plant parts while there are others which are avoided. The identification of the eaten species and the rate of their occurrence in the feed is the first step to become acquainted with the interaction between animal and the surroundings.
    On the examined territories there was significant difference between the disembowelled body masses. The does which come from the hunt Nagyszénás weighed 4-5 kilos more than the does from the Csongrád territory. The main feed components were present in different rate in the samples of the territories, in the Nagyszénás samples grain, dicotyledonous herbacous plants were dominant, and were eaten more. The high level of grain in the feed result in better condition and larger body mass.

  • The possibility of increasing at the conjugated linoleic acid content in pork
    27-32
    Views:
    116

    The composition of fatty acids in food products is a significant factor in human health. Feeding can significantly influence the composition of fatty acids in the animal fat. We analysed the effect of feeding high CLA-content (conjugated linoleic acid) feed on the composition of fatty acids in pork. The animals were grouped according to the following: Group 1) feeding experimental, ghee-mixed feed for 76 days, Group 2) feeding the same feed, but only for 33 days, Group 3) feeding sunflower-oil-mixed feed for 76 days. Ghee contains CLA in high amount. The aim of our experiment is to analyse how the high CLA content influences the fatty acid content of pork. In the end of the fattening experiment the animals were slaughtered, then samples were taken from the loin, ham, abdomen and backfat from 10 animals from each group and analysed the fatty acid content. We found significant differences between the average fatty acid content of the samples. As an effect of feeding ghee-enriched feed, the CLA content significantly increased, compared to the control group. However, the linoleic acid and the arachidonic acid content were lower, and the proportion of fatty acids was also lower when feeding control feed.

  • Trends in Dry Pea (Pisum sativum L.) Production
    53-58
    Views:
    125

    Dry pea is an important, cool-season grain legume, which is grown worldwide on over 6 million hectares. The major producing countries outside Europe are China and Canada, followed by India, Australia, and the United States. France, Canada and Australia produce over 2 million hectares and are major exporters of peas. During the 1980’s, in developed countries of the European Union, pea production rose yearly by 6-10%, which represents a significant increase in both area and yield. Europe accounts for 50-75% of world pea production. In the 1990’s, the European Union produced 4-5 million tonnes of dry pea, of which 3-4 million tonnes were used for feed and 1 million tonnes for export. At the end of the 20th century, the growth in production was low, mainly because of the absence of support measures, and the better returns offered by other crops. In the countries of the former Soviet Union, dry pea was primarily used as feed and pea production dropped, due to a trend in livestock raising.
    Food consumption of dry pea is concentrated in developing countries, where grain legumes represent a useful complement to cereal-based diets as a relatively inexpensive source of high quality protein. As a result, human consumption of grain legumes fell from 2,2 kg/capita in 1961 to 0,5 kg/capita in 1999. The importance of grain legumes in food protein supply decreased, while that of cereal products increased. Shortage of grain legumes has adverse effects on the nutritional standard of poor people in developing countries.
    World dry pea production reached 16,7 million tonnes in 1990, with 3,7 million tonnes used as food, 11,4 million tonnes used as feed, and 1,0 million tonnes used as seed. Dry pea production was 10,9 million tonnes in 1999, and 3,5, 5,8 and 0,8 million tonnes was used as food, feed and seed, respectively. In the coming decades, world grain legume production and utilization as feed are expected to expand at a slower rate than in the 1980’s. Most of the increase is expected to occur in Eastern European countries, Canada and Australia, where production is anticipated to grow at 2% annually. The projection for the new millennium was derived from adjusted trends in area and yield over the period 1961-2000, based on FAO statistical data.

  • Examination of the main parameters of roe deer feed compound on two territories
    13-16
    Views:
    99

    It is widespread that roe deer are very choosy. He needs this sorting because the micro organizms, which help the digestion of high fibre plants, are missing in his stomack, that is why they are mostly called „concentrate selectors” Hoffmann, 1985, 1988, 1989).
    These animals should mostly eat easily digestable plants with high nutrition level (pulses, buds, sprouts and flowers), and they are able to do this sorting because of their small mouth size. In winter there is a lack of these plants, so the high selectivity occurs only when the feed is in abundance.
    Examining the amount and quality of vegetation available on the habitat of roe deer we can identify the species which can satisfy their feed demand. It is known, that roe deer as other large ruminants, from the plant abundance prefer certain plants and plant parts while there are others which are avoided. The identification of the eaten species and the rate of their occurance in the feed is the first step to become acquainted with the interaction between animal and the surroundings. 

  • Effect of different lysine-metabolized energy ratio on performance of meat-type geese
    39-42
    Views:
    184

    The aim of the experiment was to determine, how the different ratios of the digestibility lysine/ metabolized energy (0.82, 0.87, 0.91 g DLYS/MJ AMEn) of the feed influence the performance of geese. There were 150 goslings (3 treatments, 5 cages/treatments, 10 birds/cages). The experiment has started and finished at the age of 3 and 9 weeks, respectively.
    The results of the experiment showed, the different ratios of DLYS/AMEn (0.82, 0.87, 0.91 g DLYS/MJ AMEn) did not influence the performance of young geese. Better growth performances were found for the 0.91 g DLYS/AMEn feed (feed intake, body weight gain, feed and energy conversion rate). This treatment coincided with high feeding costs. Based on these results we need more models and farm experiments to prove this tendency.

  • Realisation of customer focus from quality and forage safety aspects in the Hungarian mixed feed production
    35-38
    Views:
    113

    Customer focus is one of the main principles of Total Quality Management, and it is inevitable for long term, mutually successful vendorcustomer partnerships. The strictly controlled quality management systems of animal feed industry ensure that product quality meets the expectations of all parties involved and, indirectly the reliability of human food raw materials. Meanwhile, the participants of agricultural production are variably quality conscious, so feed manufacturers support their supply chain and also their customers with professional background and they play a key role in safe food chains from farm to fork.

  • Investigation of the effect of allithiamine-enriched feed on the poultry gut microbiome composition and resistome
    149-155
    Views:
    66

    Over the past 20–25 years, the poultry industry has evolved into a specific protein production system. However, the stress resulting from intensive rearing practices has led to numerous negative consequences, making the optimisation of livestock gut microbiome composition crucial for mitigating these effects. Advancements in modern molecular biology methods have brought attention to the impacts of nutrients on gut microbiota. In our study, we extensively investigated the changes induced by feed formulations rich in phytonutrients on the gastrointestinal microbiota of livestock using targeted 16S rRNA amplicon sequencing. Our objective is to examine how the developed feed prototype affects the composition of core microbiomes in raised poultry, community diversity, and the resilience of complex microbial networks. We seek correlations between biological livestock and environmental samples to identify which community constituents, in what proportions and occurrences, may play a role in the development of specific diseases. Based on our measurement results, it can be asserted that allithiamine positively modulated "beneficial" community constituents. Beyond the impact of allithiamine-enriched feed rich in phytonutrients, the composition of the microbial community in the poultry gastrointestinal tract is significantly influenced by the age of the birds. Furthermore, due to the presence of multi-drug-resistant pathogens in environmental samples from livestock facilities, appropriate transmission risk management measures are of paramount importance.

  • Insect base-protein: A new opportunity in animal nutrition
    129-138
    Views:
    450

    The consumption of insect protein, as well as its use in animal feeding, has become a trend. This trend is particularly receiving a lot of attention in animal nutrition because the current protein source of the highest quality in animal feeding which is fishmeal is unsustainable, expensive and its demand is higher than supply. Insect protein can be of great potential in combating world hunger as the world population continues to increase. The potential of insect protein is wide-ranging, it could improve the economics of feed production, lead to cleaner production due to its low environmental footprint.

    This review focuses on the need, (nutritional and environmental) advantages of insect protein in feed production, as well as previous research findings.

    The unanimous conclusion of the reviewed papers is that insect protein has a great potential in feed production in terms of nutritional value, environmental implication, sustainability as well as economic implication.

    However, there is a need for the intensification of research on this alternative protein source in Europe, especially in aquaculture due to the approval of 7 insect species in aquafeeds by the European Union. Another reason for the intensification is that there is still much to be done as a result of past research which shows that growth effects vary based on species and inclusion level.

     

  • Some Variable Traits of Broiler Genotypes
    25-30
    Views:
    132

    One the most effective ways to satisfy the requirements of mankind for food of animal origin is the fattening of chicken. Healthy and cheap meat with low fat and high protein content can be produced rapidly and in large quantities by broilers with low feed consumption. This paper presents the production results and carcass traits of three genotypes (Ross 308, Cobb 500, Ross broiler parent) females and males at the age of 42 days.
    In both sexes, we found that the average body weight of the Ross parents genotype was higher (females: 2643 g; males: 3089 g) than the
    average body weight of the other two hybrids – significant difference was found only between pullets. However, the smallest difference in the
    average body weight between the two sexes (446 g) was found in this genotype. In both sexes, the lowest average weight was detectable in
    the case of the Cobb 500 hybrids (females: 2443 g; males: 3052 g).The feed consumption ability of the females were worse – in all but one
    case (Ross pullet) – than that of the males. For one kg of weight gain - in the order of genotypes – 1.79kg, 2.08kg and 2.08 kg of feed was
    used. The same values for the males were as follows: 1.81kg, 1.80kg and 1.89 kg, respectively.
    Carcass traits were examined and it was found that the average grillfertig weight, the weight of whole thigh meat and thigh meat of the
    Ross parents’ genotype was higher than the average weight of the other two hybrids. Significant difference was found only in grillfertig- and
    whole thigh meat weight. Pullets of the Ross parents’ paternal line had worse results in the average weight of breast meat with bone and
    breast meat fillet than the other two genotypes. In the case of cocks was detectable the inverse of this: the average weight of breast meat with
    bone was the highest in the cocks of the Ross parents’ maternal line.

  • Role of hypothalamic neuropeptides in feed intake regulation of livestock species (literary review)
    63-68
    Views:
    176

    Energy balance is the net result of the energy intake (nutrition) and expenditure (basic metabolic rate). The purpose of the daily feed intake is to provide energy and nutrients for maintenance, production and fill and maintain energy storages in form of glycogen and fat. Animals can adjust their feed intake to ensure their energy demand. Food intake regulation in animals and human is a very complex process, in which the digestive system, the central nervous system, the joining hormonal and non-hormonal factors, and the integrating hypothalamus take part. This review primarily focuses on the action mechanism of some important appetite regulating neuropeptides, and their impacts on the performance traits of the economically significant animal species.

  • Effect of different weaning time on the growth and survival ofCommon carp (Cyprinus carpio L.) larvae
    55-59
    Views:
    279

    Within 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.

  • Analysis of the main parameters of spring and summer food compound of roe deer (Capreolus capreolus L.) on the two hunting grounds of the Alföld plain
    7-10
    Views:
    92

    It is widespread that roe deer are very choosy. It needs this sorting because the micro organisms, which help the digestion of high fibre plants, are missing in its stomach that is why they are mostly called „concentrate selectors” (Hoffmann, 1985, 1988, 1989).
    These animals should mostly eat easily digestible plants with high nutrition level (pulses, buds, sprouts and flowers), and they are able to do this sorting because of their small mouth size. In winter there is a lack of these plants, so the high selectivity occurs only when the feed is in abundance.
    Examining the amount and quality of vegetation available on the habitat of roe deer we can identify the species which can satisfy their feed demand. It is known, that roe deer as other large ruminants, from the plant abundance prefer certain plants and plant parts while there are others which are avoided. The identification of the eaten species and the rate of their occurrence in the feed is the first step to become acquainted with the
    interaction between animal and the surroundings.

  • Effect of fish feeds with high vegetable oil and low fish oil content on the growth performance and innate immune system of common carp (preliminary results)
    7-12
    Views:
    76

    Fish meal and fish oil are very important components of fish feeds used by aquaculture. They contain poly-unsaturated fatty acids, which are essential nutrients both for fish and human nutrition. However, sources of fish meal and fish oil are limited, there is a need for new feed components to supply the increasing fish production and the increasing demand for fish feed. The aim of AQUAMAX project, supported by the European Union is to replace the fish meal and fish oil with vegetable oils. As a participant of this project, group of immunology in Research
    Institute for Fisheries, Aquaculture and Irrigation (HAKI) examined the effect of three different fish feeds on the growth performance, innate immune response and resistance against Aeromonas hydrophila infection of common carp in an in vivo experiment. Fish feed supplemented with Camelina oil, but still containing fish oil significantly increased growth performance of experimental fish and their resistance against the infection. Fish feed containing linseed oil only did not enhance the growth performance, and it had a negative effect on resistance against infection. Based on the experimental results it can be concluded that fish oil used in fish feeds cannot be replaced effectively with vegetable oils, but can be supplemented with them. 

  • The effects of the nanoselenium supplementation to the production parameters and the selenium retention of the red drum (Sciaenops ocellatus)
    43-48
    Views:
    196

    The selenium is an essential trace element with antioxidant effect, constituent of many enzymes, natural component of the body of the animals. The addition to the fish feed as micro element supplementation is generally accepted. Numerous animal experiments veryfied, that the antioxidant effect of the nanoselenium is higher than other selenium forms. But no much information is available of the usuage at fish.

    In the experiment were investigated the effects of the nanoselenium supplementation of a commercial fish feed were investigated to the production parameters and the body tissue composition. The correlation between the accumulated selenium content of the body and the treatment, and the feed conversation was also statistically analyzed beside the production parameters. Furthermore we were curious, if can be toxic the nanoselenium in higher doses.

    The experimental stock was placed into 12 plastic tanks (each 70 l water vol.) in a recirculation system for larval rearing. The salinity and the water temperature was constant during the 8 week long experiment. The feeding was ad libitum, 4 times a day. Beside the control five (1, 1.5, 2.5, 5.5, 10.5 mg Se kg-1) duplicated treatment were set.

    According to the results, from the production parameters only at the value of FCR and the survival was found significant difference (p<0.05) between the groups. However strong correlation (r=0.752–0.780, p<0.01) was determined between the treatment and the accumulated selenium levels. To analyzed the free fatty acid contentof the fish, we realized, that the selenium uptake significanly enhanced this level at all treatments. The greatest change was found in case of the type n-3 fatty acids.

    Established by the results, the higher intake than 0.5 mg Se kg-1 was not changed significantly the production parameters, nevertheless to increase the selenium content of commercial feeds to 1.5 mg Se kg-1 could be rewarding on the rearing of red drum.

  • Some basic problems concerning world animal production at the beginning of the XXI century
    77-80
    Views:
    111

    The author summarizes the main new challenges facing animal agriculture: growing GDP in many countries increasing animal protein demand, bioenergy industry as a new player using potential food or feedstuffs, increasing demand, Growing water and land scarcity, weaking the position of plant agriculture, feed production. Forecasts are summarized regarding the magnitude of meat consumption increases, and the possible plant biomass quantities required additionally in the next 20 years to cover the needs of food, feed and biofuel on a global scale.
    Efficiencies of various animal production sectors, poultry, pork, beef, mutton meat, milk and eggs and their environmental footprints are compared, summarizing the most important research  results concerning UK, USA, OECD evaluations. Intensive systems using highly productive plant and animal population will play an even more important role in the future especially in poultry, pig, milk and aquaculture production system being efficient users of resources (feed, water, land) and the environmental foot print is smaller per unit product.

  • Effect of dietary fatty acids on the oxidative stability and the colour of broiler meat
    25-30
    Views:
    77

    The aim of our investigation was to determine the effects of increased PUFA (polyunsaturated fatty acids) content on the colour, total pigment content, organoleptic characteristics and oxidative stability of poultry meat. The experiment was carried out with 1200 Ross-308 cock chicklings. Animals were fed with a 3 phase diet, and in each phase, additional fat was added to the feed. The isocaloric and isonitrogenic feed was produced as the breeder organization suggested; only the fat content differed (4 treatments: pig fat (lard), sunflower oil, soy oil, flax-seed oil).
    The different fat complements did not influence broiler production. However, the fatty acid composition of meat was similar to the fatty acid composition of feed (additional fats). The analyses of meat samples, after a storage period, did not significantly prove the possible negative effects of higher PUFA content.

  • The effect of different fat content fish feed on the production parameters and meat quality of the hybrid striped bass
    33-37
    Views:
    159

    The interspecific ’hybrid striped bass’ is the result of cross breeding. Their offspring have got good chances of growth and tolerate extreme water temperatures and the content of dissolute oxygen more than their parents. Furthermore, they are more resistant to diseases. Therefore, the hybrid is perfectly suitable for intensive fishery production.

    Our experiment lasted for seven weeks. We analysed the indices of growth and production of the hybrid as the consequence of nurturing them with two feeds of high nutritive value during this period. We examined the content of fat and of fatty acids in the flesh of these fish. There were no considerable differences in terms of weight gain, feed conversion ratio and uneven growth between the two groups, while survival was less likely among the the fish which had consumed more fat. We demonstrated, examining the flesh of the individuals which had consumed feed containing lower fat content, that it was fattier and contained more dry matter than those that had been fed of higher fat content. Besides, the content of omega-3 and omega-6 fatty acids was higher in the fish that had consumed less lipids.

  • Preliminary results on Siberian sterlet (Acipenser ruthenus marsiglii) fries rearing under intensive conditions
    27-31
    Views:
    116

    In 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.

  • Does the feeding frequency influence the growth performance of European perch juveniles (Perca fluviatilis) during intensive rearing?
    123-128
    Views:
    120

    The European perch (Perca fluviatilis) is a predatory fish species. Its aquaculture production is increasing worldwide. Feeding and the frequency of feeding are important elements of intensive fish rearing. The aim of our experiment was to examine the optimal distribution of the amount of feed, at the same feed rations. The experiment lasted 42 days. Three treatments were applied in 4–4 replications. The first treatment was feeding twice per day (T2), the second treatment was feeding three times a day (T3), and the third group was fed four times a day (T4). 10 European perch juveniles were stocked per tank, with an individual mean body weight of 3.93 ± 0.06 g at the start of the experiment. The survival rate (S%) was above 90% for all treatments. The T2 treatments produced the most favourable harvest weight (13.96 ± 0.14 g) and specific growth rate (SGR = 3.08 ± 0.01% day-1), but no significant differences were observed between groups. In terms of feed conversion ratio, the best result was obtained by (T3) (FCR =1.06 ± 0.18 g g-1), but no significant difference was found for this indicator neither. The results of the trial indicate that the feeding frequency does not influence the production parameters.

  • The Effects of Corn Cobs in Feed
    51-54
    Views:
    99

    This study is part of a larger research work that aims to establish the usefulness of corn cobs, a low cost dietary resource, in the growth of ruminants. Corn cobs are found in large amounts in our country (8.2 mil. tons/year). Increasing the quantity of corn cobs to 50% of the diet in lambs resulted in a decrease by 14.57% in the concentrate intake that is needed to obtain one-kg weight increase. In addition, the diet costs were reduced by 16.33% (Mierliţă, 1999). Increasing the quantity of corn cobs to 20-50% of the diet also resulted in multiplication of bacteria from genus Ruminococcus, that are known to represent about 70-80% of the bacteria population in the rumen. In addition, an increased multiplication rate of large protozoas (i.e. Epidinium, Isotrichia, Diplodinium etc) was observed. This explains the high conversion rate of piruvic acid, a carbohydrate fermentation product, into acetic acid, whereas conversion of piruvic acid into propionic acid decreases. In addition, feed intake and the quantity of digested and absorbed fibers increased by 8.46% and 35.09%, respectively. Thus, a reduction in dietary concentrates needed as nutrient supplies was achieved.