UNIVERSITY OF PANNONIA. DOCTORAL (Ph.D.) THESIS. Intensive rearing of pike (Esox lucius L.)

Átírás

1 UNIVERSITY OF PANNONIA Georgikon Faculty of Agriculture, Keszthely Department of Animal Science and Animal Breeding DOCTORAL (Ph.D.) THESIS Doctoral School of Animal Breeding Head of the School Dr. Szabó Ferenc DSc. Intensive rearing of pike (Esox lucius L.) Author: Kucska Balázs Keszthely

2 1. PRELIMINARIES AND OBJECTIVES OF THE RESEARCH The pike (Esox lucius) is one of the most important predatory fish species in Hungary. Its propagation and pond rearing has great traditions in the country. It is one of the most preferred fish by anglers worldwide, and contributes to the ecological balance of freshwater ecosystems. Nowadays, demand for the most popular pond species common carp is decreasing. However, the demand for pike is growing all over Europe, thanks to the rapid development of sport fishing. The polyculture fish production does not allow for more than one percent of the total yield to be pike. In my opinion, the best way to grow pike on a larger scale, is the development of intensive technologies, specific to the species, based on artificial feed rearing. Many research projects have worked with physiological, ethological features of the pike and its ecological role. The artificial feeding in intensive system is a less researched area, realization in practice still keeps us waiting. The first attempts of pellet feeding were done by Graff and Sorenson (1970). The experiments made on species living in North America (Esox lucius, E. masquinongy, E. niger, E. reicherti) were done in laboratory conditions with artificial pellet feeding. However, this method has not spread widely. The reason was the inadequate quality of feed and the missing technology. Hancz et al. (1998) worked with intensive culturing of pike in Hungary. The growth and feeding of naturally fed pike was examined in laboratory conditions. 2

3 The research aim of the dissertation was the examination of pike culturing on artificial feed. During my research work these questions should be answered: How suitable is the commercial trout feed for pike culturing? How does the dry feed influence the growth, body, composition fatty acid profile compared to natural food (live fish)? What is the effect of the different daily feed portions on the growth, feed conversion and survival of pike? How does feeding frequency influence the feed intake, growth, feed conversion and survival? Are the smaller size groups selected by grading a family - also suitable for intensive rearing? How does the initial body weight influence the growth, feed conversion and cannibalism? 3

4 2. MATERIALS AND METHODS The experiments of the artificial pellet rearing of pike were carried out in the fish lab of the University of Pannonia, Georgikon Faculty of Agriculture in Keszthely. The pike was propagated by our lab with the exception of one time where the fingerlings were brought from Bocskai Halászati Szövetkezet (Hajdúszoboszló). During the three years of my doctoral study, I carried out four different experiments of which the fry were fed by artificial feed since larvae stage: (A) Effect of natural and dry feed to body composition and fatty acid profile during three months long rearing. (B) Analysis how the daily amount of feed portions (fish fed with 1.0; 1.5; 2.0% of the total body weight) affect the growth, survival, and feed conversion. (C) Examination of different feeding frequency (twice a day and continuously) to the growth, survival, and feed conversion. (D) Analyze the growth and feed intake of pikes originated from the same parents, but with different initial body weight (w 1 : 6,8±1,56; w 2 : 10,4±2,1). The most important data of the experiments can be seen in table 1. The growth was tested by One-Way Analysis of Variance (ANOVA). The specific growth rate (SGR), feed conversion rate (FCR), condition factor, and some of the fatty acids were compared by Student s t-test. For statistical analysis STATISTICA 5.0 statistical package (StatSoft, Tulsa, OK, USA), and SPSS for Windows 7.5 (1996) was applied. 4

5 Table 1. Main parameters of the experiments Spacing Initial weight (g) Stocking density Duration of experiment Daily feed amount (body weight%) Treatment Experiment A l aquarium, 2 repeated treatment 49,0±11 10 fish/ aquarium 1,2g/l 3 months ad libitum SelectBE 3rd ad libitum prey fish Different feeds 1,0% Experiment B l aquarium, 3 repeated treatment 8,0±0,1 70 fish/ aquarium (1,4g/l) 4 weeks SelectBE 2nd 1,5% SelectBE 2nd 2,0% Different daily feed amount SelectBE 2nd Experiment C l tank, 3 repeated treatment 9,6±0,2 50 fish/ tank (1,3g/l) 4 weeks 3,5% RoyalOptima 1st Different feeding frequency 105 fish/ l 6,8±1,6 aquarium 4%(1-2. week), Experiment D aquarium, 3 repeated (3,0g/l) 90 fish/ 4 weeks 3,5% (3. week) 3% (4. week) Different bodyweight treatments 10,1±1,1 aquarium SelectBE 2nd (3,0g/l) Experiment A: analyzing the effect of natural food and feeds; Experiment B: analyzing the effect of different daily feed amount; Experiment C: analyzing the effect of different feeding frequency; Experiment D: analyzing the effect of different body weight, 5

6 3. RESULTS 3.1 Analyzing the effects of artificial feed and natural food The pike in the prey-fish treatment reached a higher final weight (w t : 193±59g) and body length (l t : 26,7±2,8cm) in a 3-month period than fish fed with artificial feed (w t : 140±44g; l t : 23,7±2,3cm). In my opinion, this is probably because of the sub-optimal composition of the pellet for the E. lucius. Moreover, the movement of the prey may also have enhanced the feeding reflex of the pike. Therefore, pike could eat prey-fish but refused to take artificial feed. The high energy content trout feed resulted in an increase of the fat content of fillet (table 2.). Feeding of artificial feed caused increased fat content in liver and the formation of abdominal fat depots. Table 2. Chemical composition of fillet. Pike fed pellet Pike fed prey-fish Dry material (%) 22,44±0,51 a 22,73±0,31 a Crude protein (%) 19,47±0,56 a 20,12±0,35 b Crude fat (%) 2,44±0,36 a 1,98±0,23 b Crude ash (%) 5,83±0,12 a 5,88±0,24 b ab means within columns with no common superscripts differ significantly There was difference in fatty acid profile of pike first fed with similar then different feed: in the rate of C14:0, C18:0, C18:1n-7, C20:1n-9, C20:4n-6, C18:3n-3, and the total monounsaturated fatty acid (MUFA) the total polyunsaturated fatty acid (PUFA) (total n-6 fatty acids). On the basis of these results, the author states that culturing pike without species-specific feed is still solvable but it is required to optimize the feed later on. 6

7 3.2 Effects of different pellet feed ration Among each daily amount of feed portions (fish fed with 1.0; 1.5; 2.0% of the total body weight) pike fed with 2% of portions had the best growth rate body weight (g) Group A 1%-ot kapó csoport Group B 1,5%-ot kapó csoport Group C 2%-ot kapó csoport induló 1. hét 2. hét 3. hét 4. hét week 0 week 1 week 2 week 3 week 4 (figure 1.). Figure 1. Growth of pike fed with different feed portion. Pike fed with (Group A) 1,0%, (Group B) 1,5%, (Group C) 2,0% of body weight. Pike fed with the smallest amount of feed achieved the most unfavorable food conversion rate, FCR (g/g) Group A: 1,05±0,04 a ; Group B: 0,87±0,08 b ; Group C: 0,87±0,02 b ). Cannibalism was not observed either of the treatments. 7

8 3.3 Effects of feeding frequency During four week long experiment the pikes fed continuously (during 24h) reached higher final body weights (w t : 26,07±1,25g) than the other treatment (w t : 21,6±1,25g) fed twice a day. Although when considering the data of weeks 2-4, there were no differences between the SGR (specific growth rate) values of treatment groups (3,2±0,4 and 3,1±0,2). Based on the results of our experiment one can conclude that after a one week long studying period, the pike is able to accustomed to a more rare feeding frequency, its feed intake increases (Figure 2.) and shows similar growth rate than other pikes fed more frequently. 3,5 3,0 feed intake (body weigth%) 2,5 2,0 1,5 1,0 Group C Gropup 2 0, Time (w eek) Figure 2. Changing of feed intake (in body weight %). Group C: fish was fed continuously, Group 2: fish was fed twice a day Cannibalism was not observed either of the treatments. 8

9 3.4 Effects of different initial weights In the 4-week experimental period the group with large initial body weight reached higher weight than the group with smaller initial weight, however in case of growing frequency the group with initial body weight had better results than the group with large weight (Figure 3.). The SGR value of the small group was 3,69±0,04, while the group with large initial body weight had only 3,4±0,09. This indicates that the differences in body weights were probably due to environmental causes, rather than to genetic factors. 35 Body weight (g) small large group large small group 5 0 week 0 week 1 week 2 week 3 week 4 Figure 3. Growth of pikes Cannibalism was not observed either of the treatments. 9

10 4. CONCLUSIONS AND SUGGESTIONS According to the results, I conclude that the break through in the intensive rearing technology of pike was successful. The growth rate, feed conversion and survival of the pike fingerlings, fed by pelleted feed are excellent and correspond to the values of some other intensively grown carnivorous fishes. Cannibalism, observed during the traditional (based on live fish feeding) farming, could be decreased to minimum in intensive rearing. The reasons of that, in my opinion, are: the adequate feed quantity and formation of homogenous groups. Our results proved that the phenomenon of cannibalism is not a significant a anymore at pikes near the same size (above 10 g pikes), and fed appropriately. The results of our experiments done in laboratories suggest carrying out pilot size farming of pike at intensive circumstances in a fish farm. In the future the most important tasks are determining the optimal stocking density in intensive system and testing the parameters of rearing in cages in lakes. After all, I expect that pellet feeding of pike will be used widespread. 10

11 5. THESIS POINTS 1. I measured and calculated the weight gain, the growth rate, the food consumption and food conversion of pike fingerlings fed either by natural food (fish) or pelleted trout feed. 2. I analyzed the body composition and fatty acid profile of pike reared on trout feed up to a certain size and then fed by fish or feed. I concluded that the fat content of the pike fingerling grown on trout feed, can be decreased by feeding it with prey-fish. 3. I have determined the weight gain and feed conversion ratio at 1,0%, 1,5%, and 2,0% daily food intake (of trout feed). 4. I estimated the influence of the feeding frequency - twice a day or continuously on the growth, feed consumption and feed conversion ratio of the pike fingerlings. 5. I concluded that smaller mean size groups of a graded pike family can also be raised intensively as well as their larger mean size group mates. I analyzed the effect of the initial weight on the survival rate, and feed conversion ratio. 11

12 6. PUBLICATIONS RELATED TO THESIS 6.1. Articles published in scientific journals Kucska, B., Müller, T., Bercsényi, M., (2007) The effect of feeding frequency on the growth and survival of pike (Esox lucius L.) using floating pellets. Journal of applied Ichthyology 23, Kucska, B., Pál, L., Müller, T., Bódis, M., Bartos, Á., Wágner, L., Husvéth, F., Bercsényi M. (2006) Changing of fat content and fatty acid profile of reared pike (Esox lucius) fed two different diets, Aquaculture Research 37, Kucska, B., Müller, T., Sári, J., Bódis, M., Bercsényi, M. (2005) Successful growth of pike fingerlings (Esox lucius, L.) on pellet at artificial condition. Aquaculture 246, Articles published in professional periodicals Kucska B., Bercsényi M. (2005) Aufzuht von Hechten mit Trockenfuttereine neue Methode für die europäische Aquakultur, Fischer und Teichwirt 56: Kucska, B., (2003) Csuka nevelése tápon. Halászat 96: Scientific presentations Kucska B. Müller T. Bercsényi M. (2006) New results in intensive rearing of Northern pike. Internetional Northern Pike Symposium: Merging knowledge of ecology, biology and management for a circumpolar species. American Fisheries Society 136th annual meeting Lake Placid, USA 12

13 Kucska B. Budaházi A. Bercsényi M. (2006) Comparison of Production parameters of graded groups of pike Esox lucius, grown on compound feed. World Auaculture2006 Conference Firenze, Olaszország Kucska B. Lévai F. Bercsényi M. (2007) A primır csuka elıállítása XXXI. Halászati Tudományos Tanácskozás, Szarvas Kucska B., Bódis M., Müller T., Merth J., Bercsényi M., (2005) A csuka (Esox lucius) mesterséges takarmányozásának vizsgálata különbözı napi takarmányadag-mennyiségekkel XXIX.. Halászati Tudományos Tanácskozás, Szarvas Bódis M., Kucska B., Sári J., Müller T., Merth J., Magyar L.., Husvéth F. Bercsényi M., (2004) A mesterséges takarmány és a természetes táplálék hatása a csuka (Esox Lucius) és a süllı (Sander lucioperca) növekedésére és testösszetételére XXVIII. Halászati Tudományos Tanácskozás, Szarvas Kucska B., Sári J., Kiss B., Magyar L., (2004) A mesterséges takarmány és a természetes táplálék hatása a csuka növekedésére és testösszetételére X. Ifjúsági Tudományos Fórum Keszthely CD kiadvány 1-5 Kucska B., Bódis M., Merth J., Müller T., Sári J. (2003) Tavi kihelyezésre alkalmas., egynyaras csuka és süllı nevelése tápon. XXVII. Halászati Tudományos Tanácskozás, Szarvas, (Abstract book p 41Halászatfejlesztés, Vol. 28, pp ) Bódis M., Kucska B., Merth J., Bercsényi M. (2003) Ragadozó halak intenzív, tápos nevelési technológiája I. (laboratóriumi és tavi ketreces eredmények) EU Konform Mezıgazdaság és Élelmiszerbiztonság, Nemzetközi Tudományos Konferencia, Gödöllı, EU konform Mezıgazdaság és élelmiszerbiztonság II. pp:

14 Bercsényi M., Kucska B., Bódis M., Müller T., Merth J. (2002) Ragadozó halak tápos nevelése Ágazati Tanácskozás a ragadozó halakról, Szent István Egyetem, Gödöllı Kucska B., Binder T., Bódis M., Müller T., Merth J., Keresztessy K., Bercsényi M. (2002) Kísérletek négy ragadozóhal - csuka süllı menyhal sügér tápon való nevelésére XXVI. Halászati Tudományos Tanácskozás, Szarvas 7. PUBLICATIONS NOT RELATED TO THESIS 7.1. Articles published in scientific journals Müller, T., Taller, J., Nyitrai, G., Cernák, I., Kucska, B., Bercsényi, M. (2004). Hybrid of pike-perch (Sander lucioperca) and Volga pike-perch (S. volgense, GMELIN). Aquaculture Research, 35(9), Szabó, G., Müller, T., Urbányi, B., Bercsényi, M., Kucska., B., Horváth, Á (2005) Cryopreservation of eel sperm. Acta Biologica Hungarica 56(1-2), Bódis, M., Kucska, B., Bercsényi, M., (2007) The effect of different diets on the growth and mortality of juvenile pikeperch (Sander lucioperca) in the transition from live food to formulated feed. Aquaculture International 15(1), Scientific presentations Bódis M., Makkosné Takács Sz., Sutina L., Kucska B., Müller T., Bercsényi M., (2005) Süllı (Sander Lucioperca) nevelése száraz táppal- Tápra szoktatási módszerek vizsgálata és ketreces eredmények XXIX.. Halászati Tudományos Tanácskozás, Szarvas, 14

15 Müller T., Nyitrai G., Kucska B., Bódis M., Bercsényi M. (2005) A kısüllı mesterséges szaporítása XXIX.. Halászati Tudományos Tanácskozás, Szarvas, Müller T., Merth J., Nyitrai G., Kucska B., Bercsényi M. (2003) Sügérfélék (percidea) hibridizációjának lehetségei: elızetes eredmények. XXVII. Halászati Tudományos Tanácskozás, Szarvas (Abstract book p. 18, Halászatfejlesztés, Vol. 28, pp ) Szabó Tamás, Lefler Kinga Katalin, Béres Gábor, Kucska Balázs, Bódis Márk, Bercsényi Miklós, Radics Ferenc, Horváth László (2007) Ragadozó halfajok gametogenezisének vizsgálata XXIX.. Halászati Tudományos Tanácskozás, Szarvas, Total Impact Factor: 5,6 15