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Testing of production efficiency during culturing of market size of North African catfish (\kur{Clarias gariepinus}) using specialized feeds with an substitute of fish meal in semioperational conditions of RAS
HOUDA, Ondřej
There was considered production efficiency of three kinds of feeds with a partial substitute of fish meal specified to intensive culturing of "catfishes" in North African catfish in semioperational conditions of RAS in present BSc. thesis. There were made use of feeds by the Dutch company Coppens (CATCO SELECT - 13EF, CATCO GROWER - 12EF) and feed by the Hungarian company Haltáp. The individual feeds differed particularly from the contents of fat and from the contents and the origin of a proteinous component. The temperature in the course of the whole experiment was 24.5 ? 0.95 °C (mean ? S.D.), pH was 7.2 ? 0.34 and the content of dissolved oxygen was 2.4 ? 0.34 mg ? 1 O2. The experiment was divided into three particular feeding periods 20 days at a time and it took 63 days in total. The size of optimal relative daily ration served to fish along the line of the experimental attempt made in the event of feed SELECT - 13EF 1.40 ? 0.29 % (mean ? S.D.), GROWER - 12EF 1.28 ? 0.21 % and Haltáp 1.94 ? 0.06 %. Next production parameters were followed in the course of own attempt: individual weight, stocking density of tank, specific growth rate (SGR), food conversation ratio (FCR), protein efficiency ratio (PER), gonadosomatic index (GSI), Fulton's coefficient of condition and utilisation rate. Average stocking density of fish in tank was 53.49 ? 0.36 kg ? m-3 at the start of the experiment and 168.75 ? 12.23 kg ? m-3 at the end. Average individual weight of fish at the beginning of the experiment was 269.64 ? 10 g and by the end 642.85 ? 55 g. In the course of testing it came to average increase in individual weight approximately 2.4 times. Resulting mortality along the line of the experimental period was on level 1.25 %. The hightest achieved SGR was discovered at the group feeded by feed SELECT - 13EF (1.58 ? 0.41 % ? d-1), the group feeded by feed Haltáp came after (1.38 ? 0.38 % ? d-1). The most favourable values FCR were achieved by use of feed SELECT - 13EF (0.83 ? 0.02), the group feeded by feed GROWER - 12EF (87 ? 0.01) followed, the worst result was achieved by use of feed Haltáp (1.37 ? 0.13). The most favourable values PER were achieved at fish feeded by feed SELECT - 13EF (2.89 ? 0.08), feed GROWER - 12EF (2.54 ? 0.04) followed and the worst results were found out by use of feed Haltáp (1.65 ? 0.14). GSI was growing on average five times higher values (2.65 ? 1.34) at females than at males (0.53 ? 0.26). The difference of achieved GSI depending on used feed was not found. Fulton's coefficient of condition acquired average value at females 1.09 ? 0.10 and at males 1.06 ? 0.07. Average value of utilisation rate acquired at females 39.96 ? 1.26 % and at males 40.46 ? 2.33 %. The lowest expense per weight gain (evaluated for increase of 1 kg) were noticed at feed Haltáp (41.33,- CZK), feed SELECT - 13EF (41.98,- CZK) came after and feed GROWER - 12EF proved to be (44.02,- CZK) the worst. The review of analyses of organoleptic qualities (consistence, smell, taste and aftertaste) and the preferential analyses did not show any significant, demonstrable influence of used feed on quality of gained flesh. Evaluators (35.77 % of respondents) labeled the sample of muscle of catfish feeded by feed Coppens CATCO SELECT - 13EF as the most delicious.
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The efficiency testing of production commercial feeds for african catfish (Clarias gariepinus)
PETR, Miloš
In my diploma thesis I was tested six types of feed. I tested in 3 repetitions in the recirculating system with biological treatment of water. Tested fishes african catfish (Clarias gariepinus) weighted between 200 ? 800 g per piece, were deployed into 18 aquariums with volume of 190 litres per aquarium. The whole experiment took place in five partial 3-week periods in the intensive breeding of the laboratory - controlled reproduction of fishes FROV JCU. The average water temperature during the experiment was 27 °C. The main objective of the thesis was to observe production efficiency of tested types of feed, speed of the growth of fishes, feed rates and financial costs. Afterwards, determinativ of yield and organoleptic evaluation was determined, followed by laboratory examination of composition of meat. The results of production indicators (Specific Growth Rate, Relative Growth Rate, Food Conversation Ratio) were most favorable for 3 types of feed ? Haltáp (SGR=0,81 %; RGR=126 %; FCR=1,45), Coppens TROCO SUPREME-22 (SGR=0,73 %; RGR=105 %; FCR=1,19), Coppens TROCO PRIME-18 (SGR=0,68 %; RGR=97 %; FCR=1,26). The lowest costs for 1 kg of fish increment were achieved for these specific types of feed Haltáp and Aller Aqua Focus (45 Kč a 46 Kč). In the organoleptic analysis was found positive evaluation of meat of all tested fishes. Chemical composition of meat was (in term of proteins and fats content) most favorably documented for the hungarian feed called Haltáp (proteins=19,22 % and fats=4,85 %).
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