Solving the problem of feeding the carps (Cyprinus carpio) in early stages

Jedan od ključnih problema u proizvodnji šaranskog mlađa je uzgoj ličinaka i mjesečnjaka u proizvodnim, odnosno ribnjačkim uvjetima. U zadnje vrijeme se pokušava izraditi odgovarajuća početna krmna smjesa koja bi zamijenila živi zooplankton i uzgoj u kontroliranim uvjetima. Više od 40 godina nutricionisti iz područja ribarstva nastoje riješiti navedeni problem, ali do sada samo s djelomičnim uspjehom. Prva etapa u razvoju početne krmne smjese za hranidbu ranih stadija šaranskih riba trajala je tijekom sedamdesetih i osamdesetih godina prošlog stoljeća. U početku su hranidbeni pokusi provođeni na juvenilnim ribama, a dobiveni rezultati su se neuspješno primjenjivali na ličinkama i mladuncima. Tek od polovine osamdesetih godina utvrđena su potpunija saznanja o hranidbenim potrebama ličinaka i mladunaca šarana kako u kvalitativnom tako i kvantitativnom pogledu. Nakon saznanja o građi i funkciji probavnog trakta i pripadajućim organima, te poslije niza hranidbenih pokusa naglašena je bitnost živog zooplanktona prije prelaska na hranidbu potpunim krmnim smjesama.One of the main problems in rearing carp in early stages of development is the technology of larvae and fingerling feeding in controlled conditions and the fabrication of appropriate starter diets to replace live zooplankton. Nutritionists from the domain of fishery have been working on this problem more than 40 years, but only with limited success. The first period in the development of starter diet for carps in early stages of development went on from 1970 until 1985. At first, feeding experiments were performed on juvenile fish and the results obtained were applied on larvae and fingerlings without success. Only in the mid 80’s, the feeding needs of larvae and fingerlings view were more fully understood in quantitative and qualitative. After learning more about the composition and function of digestive tract and supportive organs, and after numerous feeding experiments, the importance of live zooplankton before changing to full feed mixture diets was stressed out

Oak dry leaves in ruminant feeding

U radu je prikazan tradicionalan način pripremanja suhog lišća hrasta (Quercus robur L.) za hranidbu životinja u Hercegovini. Kamerom je zabilježen čitav postupak od rezanja stabala, sušenja lišća i grana i spremanja za hranu preživača. Procijenjena je hranidbena vrijednost sirovine te analiziran sadržaj kalorija i koncentracija Ca i Mg. Rezultati su zatim uspoređeni s podacima u referentnoj literaturi. Zaključeno je da bi se suho lišće moglo upotrijebiti kao dodatno krmivo za odrasle preživače. To bi krmivo moglo zadovoljiti dio potreba životinja za suhom tvari, vlakninom i kalcijem.This paper presents a traditional way of preparing oak (Quercus robur L.) dry leaves for animal feed in Herzegovina. The whole process from tree cutting, drying leaves and branches and storing, by ruminant feed was recorded by camera. The nutritional value of raw material was evaluated, calory content and the concentration of Ca and Mg were also analysed. The results were then compared with the data from the referentical written material. We concluded that dry leaves could be used as roughage supplement feed for adult ruminant animals. This feed could satisfy a part of the animal needs in dry matter, fibre and calcium

THE INFLUENCE OF DIFFERENT KINDS OF FOOD ON THE ABIOTIC WATER PARAMETERS IN THE CULTURE OF CARP FRY

Istraživanja utjecaja različitih krmiva na abiotičke parametre vode provedena su u devet ribnjaka ribnjačarstva Koprivna. U svaki ribnjak nasađena su 1, 3 milijuna ličinaka šarana, a podrašćivanje je trajalo 25 dana. U postupku 1. ličinke i mladunci su hranjeni starterom tvrtke »Boha, a postupku 2. hrana je sastavljena od 50% startera »Boha« i 50% suhoga pivskog kvasca, dok su a postupku 3. mladunci hranjeni isključivo pivskim kvascem. Pokusom je utvrđena interakcija navedenih krmiva i njihova količina na dnevnu i periodičnu fluktuaciju u vodi otopljenog kisika, prozirnost i organska onečišćenost vode. Dnevna i periodična koncentracija otopljenog kisika bila je znatno viša u ribnjacima u kojima su mladunci hranjeni pivskim kvascem. Utvrđena je vrlo izražena korelacija između količine dnevnog obroka, koncentracije otopljenoga kisika, prozirnosti vode i organske onečišćenosti vode. Dnevni obroci hrane veći od 80 kg/ha ne preporučuju se ako nisu mogući protok ili prozračivanje vode.Investigations on the influence of different food on the abiotic parameters of water were carried out in 9 fish ponds on the Koprivna fish farm. 1.3 million carp fry were stocked in each pond, and the growth period lasted for 25 days. In treatment 1, larva and fry were fed with starter food from "Boha", in treatment 2 the food consisted of 50% starter food from "Boha\u27 and 50% dry beer yeast, while in treatment 3 the fry were fed exclusively with beer yeast. The experiment showed the interaction of the mentioned food and their quantities on the daily and periodical fluctuation in water with dissolved oxygen, transparency and organic pollution of the water. The daily and periodical concentration of dissolved oxygen was significantly higher in the fish ponds where the fry were fed with the beer yeast. An expressed correlation was established between the amount of daily food intake, the concentration of dissolved oxygen, the transparency of the water and organic pollution of the water. Daily feedings over 80 kg/ha are not recommended if there is no water flow or additional aeration

HRANIDBENA VRIJEDNOST PLANKTONSKOG RAČIĆA DAPHNIA MAGNA ZA HRANIDBU ŠARANSKE MLAĐI (Cyprinus carpio)

Chemical composition and contents of amino acids and fatty acids in the planktonic cladoceran Daphnia magna were investigated, aiming to evaluate its value for feeding of young carp. Crude protein, crude fat, crude fibre, ash and moisture contents were analyzed according to standard laboratory procedures. Amino acids content was determined by LKB 4101 automatic analyzer and that of fatty acids by Chrompack CP 9000 chromatograph, using a flame ionizing detector. Protein contents amounted to 1.18 and 39.24% of fresh and dry mass, respectively. These amounts of proteins completely meet nutritional requirements both of carp fry and its older categories and other omnivorous fishes. Raw fat and fibre contents in dry weight were 4.98 and 4.32%, respectively, which is suitable for the commercial carp breeding. Methionine and phenylalanine are partially in deficit, whereas other essential amino acids identified in dry mass of Daphnia magna were present in amounts adequate for all carp categories. The proportions of saturated and unsaturated fatty acids in lipids of Daphnia magna were 18.70 and 66.20%, respectively. Among the unsaturated fatty acids, the omega–3 group was present with 27.30%. The omega–3 : omega–6 fatty acids ratio was 5.68:1, which fully meets the carp nutrition requirements.Istraživanja kemijskog, aminokiselinskog i masnokiselinskog sastava planktonskog račića Daphnia magna obavljena su radi utvrđivanja pogodnosti za hranidbu šaranske mlađi. Sadržaj sirovih bjelančevina, masti, vlaknine, pepela i vlage utvrđeni su uobičajenim metodama. Sadržaj aminokiselina određen je LKB 4101 automatskim analizatorom, a sadržaj masnih kiselina Chropack CP 9000 kromatografom s pomoću plamenoga ionizirajućeg detektora. Sadržaj bjelančevina u svježoj tvari iznosio je 1,18 %, a u suhoj tvari 39,24 %. Navedene vrijednosti bjelančevina u potpunosti odgovaraju hranidbenim potrebama mlađi i starijim kategorijama šarana i drugih omnivornih riba. Količina sirove masti u suhoj tvari iznosila je 4,98 %, a vlaknine 4,32 %, što odgovara potrebama konzumnog šarana. Od esencijalnih aminokiselina u suhoj tvari Daphnia magna, fenilalanin je djelomično nedostatan dok su ostale esencijalne aminokiseline zastupljene u pogodnoj količini za sve kategorije šarana. Količina zasićenih masnih kiselina u masti Daphnia magnae iznosila je 18,70 %, a nezasićenih 66,20 %. Od nezasićenih masnih kiselina, omega–3 masne kiseline zastupljene su s 27,30 %. Odnos omega–3 i omega–6 masnih kiselina iznosio je 5,68:1, što u potpunosti odgovara hranidbenim potrebama šarana

RESULTS OF A 5-YEAR STUDY OF CAGE-CULTURE OF SHEAT FISH (SILURUS GLANIS) IN LAKE MODRAC

U radu su izneseni petogodšnji rezultati i problematika kaveznog uzgoja soma u hidroakumulaciji Modrac. Jezero je površine 1 700 ha, dubine do 18 m, a nastalo je gradnjom brane na rijeci Spreči kraj Tuzle. Fizikalnokemijski parametri vode varirali su u pogodnim granicama, osim u prvoj godini uzgoja, kada je zbog nagla zahlađenja došlo do inverzije vode, što je uzrokovalo drastično smanjenje koncentracije kisika i pomor ribe. S obzirom na temperaturu vode, razdoblje hranidbe riba kreće se od 155 do 174 dana. Za razliku od uzgoja u ribnjacima, hranidba traje od sredine svibnja do polovice listopada. Gustoća nasada u kavezima iznosila je 9 do 32 kom/m3, a masa nasada od 2,35 do 6,39 kg/m3. Ukupni prirast ribe po m3 varirao je između 2,39 i 12,02 kg. Pojedinačni dnevni prirasti soma kretali su se od 2,77 do 5,83 grama. Tako skromni proizvodni rezultati posljedica su mnogih problema koji su se javljali u tijeku uzgoja, a najbitniji su neprikladna hrana i nedovoljna količina kvalitetnog mlađa. Gubici ribe kretali su se od 1,54 do 34,1%, a nastali su zbog ihtioftirioze, kanibalizma, asfiksije i bježanja ribe iz kaveza nakon oštećenja mreža od štakora i vidri. Unatoč visokim gubicima nižim prirastima nego u ribnjacima, proizvodnja soma u kavezima zbog kvalitetnog mesa i izvoza na zapadno tržište osigurava ekonomsku rentabilnost.Presented are the results of a 5-year study and the problems of cage-culture of the sheat fish in the hydroaccumulation Modrac. The lake has a surface area of about 1700 ha, a depth of 18 m, and was created by the building of dams on the river Spreča near Tuzla. Physico-chemical water parameters varied in acceptable limits, except in the first year of culture, when because of a sudden lowering of temperatures water inversion occurred, which caused a drastic oxygen decrease and death of the fish. Depending on the water temperature the feeding period for the fish ranged from 155 to 174 days. Differing from the culture on fish farms the feeding lasted from mid-May to mid-October. The stock density in cages was 9-32 per/m3, and stock weight from 2.35 to 6.39 kg/m3. The total growth rate of fish per m3 varied between 2.77 to 5.83 grams. This kind of modest production results is due to a range of problems which occurred during the culture, the most significant being unsatisfactory food and not enough quality fry. Fish losses ranged from 1.54 to 34.1%, and came about due to the ichtyophirosis, cannibalism, asphyxiation and because of fish escaping from the cages after damage to the nets from rats and otters. Despite high losses and a lower growth rate than on the fish farms, the production of the sheat fish in cages, because of the quality of meat and export to the western market, ensures an economic rentability

LACTATE DEHYDROGENASE GENE GENOTYPIZATION FOR SPECIES IDENTIFICATION IN A FISH FARM ON THE RIVER NERETVA

There are severale Salmonid species, found in the river Neretva basin, among which S. trutta and S. obtusirostris. Also, natural hybrids such as S. obtusirostris x S. trutta have been observed. In one fish farm on the river Neretva, S. trutta and S. obtusirostris were decided to breed separately. Parental fishes were separated phenotypicaly on the basis of the morphological signs. PCR-RFLP analysis of the exon 3 to exon 4 part of the lactate dehydrogenase (LDH) C1* gene with restriction endonuclease RsaI was employed to identify the presence of other species representatives or intercrosses in two groups of juvenille fishes. Using this method, we were able to identify two S. trutta representatives in the S. obtusirostris group

ARTIFICIAL SPAWNING OF EUROPEAN CATFISH (Silurus glanis L.) USING SMALL DOSES OF CARP PITUITARY GLANDS

Istraživanja umjetnog mriješćenja europskog soma (Silurus glanis L.) primjenom malih doza saranske hipofize (CP) provedena su godine 1997. i 1995. u proizvodnim uvjetima na mrjestilištu "Ribnjak 1905" d.d. Našice. Prije hipofiziranja somovskih ženki obavljeno je obilježavanje, odvaga, procjena stupnja zrelosti i razvrstavanje u pet stupnjeva zrelosti (SZ) prema našim vlastitim kriterijima. U kontrolnoj skupini (n=21) ženke su dobile jednokratnu injekciju CP-a u dozi 4,5 mg.kg-1 tjelesne mase (t.m.), dok su u pokusnim skupinama (n=62) matice obrađene jednokratnim niskim dozama CP-a u tri razine. Ustanovljeno je da je minimalna doza CP-a za umjetno mriješćenje soma na III. SZ 2,040,15, na IV. SZ 1,590,16 i na V. SZ 1,250,10 mg.kg-1 t.m. Istodobno efikasnost mrijesta matica u odnosu na kontrolnu skupinu nije umanjena jer se kretala od 92 do 100% (p0,05), dok je relativna plodnost na III., IV. i V. stupnju zrelosti iznosila 9,92,1, 10,41,6 i 11,51,3 %, adekvatno (p0,05). Utvrđene minimalne doze CP za mriješćenje europskoga soma 2 do 3 puta niže su od relevantnih podataka iz literature. Pretpostavlja se da će one pozitivno utjecati na ostvarenje harmonične završne zriobe oocita, a time i na bolju kakvoću ovulirane ikre.In 1997 and 1998 in the “Ribnjak 1905”•d. d. Našice hatchery artificial spawing of European catfish (Silurus glanis L.) was researched under productive conditions using small doses of carp pituitary (CP). Befiwe dosing the carp pituitary glands female catfish were marked, weighed out, grouped according-to their maturity and devided in 5 categories based on grade of their maturity (MC). We used our own criteria. In the controlled group (n=21) female catfish received a single CP shot dosed at 4.5 mg. kg -1 of the body weight (b. w.), while in the experimental group (n=62) female fish were treated with single low dosed CP on three levels. It was found out that the minimal CP dosage for the artificial spawning on the 3rd MG is 2.04+-0.15, on the 4th MG 1.59+-0.16 and on the 5th MG 1.25+-0.10 mg. kg-1 of the b. m. Simultaneously, the efficiency of spawning compared to the controlled group was not reduced because it ranged between 92-100% (p<0.0.5), while relative fertility on the 3rd, 4th and 5th maturity grade totalled 9.9+-2.1, 10.4+-1.6 and 11.5+-1.3%, (p<0.05) adequately. The established minimal CP dosages for spawning of European catfish are two to three times lower than relevant data from the reference literature. It is assumed that they will have positive influence on final harmonic maturing process of the oocytes oocita, and by that on better quality of ovulated eggs