CC BY
0CULTIVATION OF RAINBOW TROUT IN FLOW SYSTEMS IN THE VALLEY REGION OF UZBEKISTAN
1Mukhammadjonova M. Q., 2Mamatkulov A.R., 3Mullabaev N.R.
1,2,3Tashkent State Agrarian University https://doi.org/10.5281/zenodo.11476945
Abstract. At the rainbow trout farm in the Namangan region of the Republic of Uzbekistan, primary materials on the effectiveness of rainbow trout cultivation in the period from fertilized to marketable weight of trout imported from France were analyzed at different times of the year. In autumn, it was shown that the import of rainbow trout with paternal caviar and the passage of the inbreeding period in the Namangan region allows the larvae hatched from it to overwinter and get a more adapted fish for subsequent breeding periods. These data indicate that in order to obtain a sufficient amount of marketable products in the Namangan region, it is necessary to take into account all factors and plan the supply of caviar in the optimal time.
Keywords: aquaculture, fish feeding, rainbow trout, Oncorhynchus Mykiss, pools, Uzbekistan valley area.
Introduction. The increase in the population of Uzbekistan is due to the intensification of work aimed at the development of biotechnology for the cultivation of various species of fish. The development of fishing in Uzbekistan is moving towards the industrial cultivation of fish in reservoirs, ponds, cages. The objects of commercial fish farming are mainly big head, carp, trout, and African catfish. By 2021, the volume of industrial fish farming in the republic exceeded 20 thousand tons (about 10% of all fish grown). Today, river trout are grown in countries with different environmental conditions, socio-economic characteristics, and for different purposes.
The commercial weight of river trout in some countries is preferably 150-250 g, in others -1 kg. In many regions, river trout are bred in order to fill reservoirs with fish intended for sports or recreational fishing. This means that higher growth rates are important for some farms, and higher sprinkle is important for some. Of course, specialists working in different regions of the world have carried out various breeding work on such a multi-purpose object. [1].
The purpose of the work is to evaluate the effectiveness of growing commercial fish of marketable weight from the spawned caviar of rainbow trout imported to the fishery at different times of the year.
Materials and methods of research. The trout farm "FISH Ville", founded by DB GROUP Eco LLC, is located in the Uchkurgan district of Namangan region, through which the Narin River flows.
Each pool has a volume of 400 cubic meters, dimensions 40x10, the bottom of the pool is inclined, the depth on one side is 60 cm, and at the end is 130 cm. The transparency of the water to the bottom of the pool. The capacity of the trout farm Fish Ville is designed to produce 1,000 tons of fish per year. The material for the analysis of biological indicators of trout fish was collected in 2020-2021. The study of fish growth is carried out with the help of a control hunt conducted twice a month. During the control hunt, at least 10% of the fish in the cage were pulled out. The data of the control hunt for each pool were recorded in a log, which recorded not only the average weight of the fish between the control hunt, but also its growth, the number of feeding days, the amount of food eaten for each individual fish and all fish in the pool, as well as mortality rates. Data processing and statistical analysis were carried out using the Excel program.
RESULTS AND DISCUSSION. In the fishing farm where the study was conducted, fish are grown in the period from caviar to commercial fish. The study covered all pools and studied all groups of fish, larvae, shellfish, annual and biennial trout introduced at different times of the year. The fish were bred with fish feeds produced by Coppens (Holland). In the spring of 2020, 47,550 fertilized eggs of rainbow trout were imported to the trout fish farm, which overwintered in the ponds of the farm and were transplanted into ponds for further cultivation in May 2021, bringing their number to 40,823. All fertilized eggs were delivered from France in containers. In total, 64 pools of 400 m3 each are grown in the open ground and 30 pools of 2 m3 each in the closed ground and up to 15 g in them.
Larvae weighing 0.2-5 grams, which after incubation switched to external nutrition, are fed with Compens food ranging in size from 0.2 to 1.5 mm. After reaching 5-10 grams, the stratum switches to premium food. After that, the chickens are transferred to a fish breeding workshop, where they are fed up to 5-15 grams of Advance feed and up to 10-35 grams of pre-grower feed.
When the fish reaches 5 grams, they are counted to determine the number of fish, when they reach 15 grams, they are sorted, after which they continue to be fed with a Supreme 22 bait with a diameter of up to 3 mm until they reach 150-200. Here they skip the feed with a feed size of 4.5 mm and immediately switch to a size of 6 mm. During this period, 35-90 g of fish grows very intensively, up to 500 g of 6 mm granules are used. After 500 g, the fish are fed with an 8 mm Astax-22 bait. Over the period from 2-2.5 grams of caviar to 5 grams, the water temperature fluctuated between 10-14 oC.
16 14
u
S 12
M
■S 10
a?
D
aj a.
£
aj
01.04.2021. 19.05.2021. 21.05.2021.09 06. 2021.17.06. 2021.09.07.2021. 17.07.2021.
Date
Figure 1. Temperature change in pools If the water consumption is less than required, the development of caviar, fingerlings and adult fish is at risk. A properly calculated flow in the pools provides sufficient fresh water for all fish, but the flow must be fast and exceed 3 cm/s (1.8 m/min) in order to flush most of the suspended waste from the pool. In pools, the size and quantity of fish in ponds should be proportional. When the water flow becomes too fast, the fish uses extra energy to stay in the stream. For this reason, too much current is also inconvenient. That is why it is so important to maintain an optimal water flow for proper water supply, adequate oxygen saturation and disposal of waste such as garbage and uneaten food particles [2].
It is known that with a gradual increase in water temperature in spring, the intensity of trout feeding increases sharply and, as a result, the growth rate increases. In early summer, the water temperature in Namangan often reaches optimal values, which has a beneficial effect on growth rates (Fig.1). At the first stage, the growth of larvae proceeded evenly, as shown in Figure 2, and
0
during this period the growth rate in July was slightly higher, in June, the larvae gained weight from 16 to 100 grams.
At the next stage, 100-gram fingerlings reach maturity by December, annual fish weighing 600 grams (Fig.3). Figure 4 shows the commercial fish growing phase, during which the fish grew smoothly and over the next 13 months in December 2022, this fish weighed 2,000 grams. The lack of water in general to the optimum temperature for commercial fish determined the growth potential, and the presence of additional factors slowed down growth in certain periods. Among such factors, turbidity of the water can be distinguished (Fig.5). Errors in the design of the pool, which did not allow optimal water exchange, and caused the accumulation of turbidity at its bottom. As a result, the fish refused to feed during these periods or ate very slowly, which basically corresponds to the period of floods, i.e. coincides with the period of precipitation (Fig.6). These figures show that, despite the fact that the temperature and oxygen conditions in the pools are not always optimal, the fish does everything possible to create favorable conditions for trout cultivation, as evidenced by the presence of live fish weight of 1800-2000 g at the end of the growing season.
18
16
„ „
14
m 12
ou
g 10 8 6 4 2 0
M
eu M £
«V c\V
. ■ 1
..........Ill 11
cO
c\V
csV
«V c\V
WV
o>
csV
csV
«V
csV
nV
WV
r\V .cCV
.V
JV ¿V ¿r ¿F JF ¿V .V
& ^ Ç$V <?> <$> & & & & é>
" & NV ^ ,«5 " ' ~ " -
«S*
<V
Date
Figure 2. Indicator of fingerlings growth before the breeding season
120 100 80
kS 60
M
40 20 0
e
M c
I
&
J3'
Days
14 12 10
s8 y
a
aD 6
4 2 0
II
04.2021. 05.2021. 06. 2021. 07. 2021. Days
Figure 3.Indicators of growth of fingerlings Figure 6. The number of days the fish were not fed
700
™ 600 +J
M 500
QU
^ 400
300 200
M
eu M
100
I I I I I
cV
iV
III
,v
•r
,-V0 0 r!!S- „^
nV
cnV
cCV1
.V
e\V
Date
2500
2000
1500
Figure 4. Growth indicators of fingerlings
■ 111111
«o- «o- «o- «Ç>- «o- /f>- «o- /fV # # # # # # <V° ¿V cF ^ ^ ^ J?
f.* * ¿>VJ f f f J J f J
Sana
.N
<V- & & ^ V
0
Figure 5. Growth of commercial rainbow trout Conclusion. Although Coppens feeds show positive indicators when growing rainbow trout for food in Uzbekistan (Namangan region), some conditions are violated here when keeping fish, such as turbidity, temperature, water exchange in pools, lack of nutrition. Accordingly, the growth of the fish slows down somewhat. The reason for the change in water quality is heavy rains in spring, when the water becomes very turbid, and there are also flaws in the design of pools that prevent rapid water exchange. But the main losses here are observed during the incubation of imported caviar, during this period up to 60% of the embryos die. The reason for this may also be the quality and temperature of the water, as well as an indication of the incubation technology.
LITERATURE
1. B. G. Kamilov, I. I. Khalilov. Growing river trout in Uzbekistan: practical recommendations for farmers (in Uzbek). Tashkent: Baktria press, 2014. — 96 P.
2. Barulin, N. V. Aquaculture price tag species fish and thrifty Technology (in Russian). V.
3. Part 1. Forestry: an educational and methodological guide / N. V. Barulin. - Gorky: BGSXA, 2018. - 237 P.
4. Zarubin, A V Growing rainbow trout in cages in reservoirs Central Russia / A V Zarubi /Agrarian Sciences - 2006 - No. 12 - P 21- 22 P.
5. Kryukov, V I Fish Farming Cages trout breeding / V I Krukov, A V Zarubi - Ore Publishing House OrelGAU, 2007 - 32 P.
