INFLUENCE OF FEED WITH DIFFERENT LEVEL OF PROTEIN ON THE GROWTH OF FINGERLINGS OF CARP (Cyprinus carpio) IN CAGE AQUACULTURE CONDITIONS OF UZBEKISTAN

ABSTRACT

In the May 2022, common carp (Cyprinus carpio) fingerlings with initial body weight 25 g in average were stocked to 9 cages (1m³ each) with stocking rate 30 fish/cage in Karkidon reservoir, Uzbekistan. Farm-made feeds from the same ingredients with protein levels 25, 33, 41 % were used in different variants (in triple replication). Feeding rate was 5 % of fish biomass in each cage. In 53 days, the highest rates of growth and feed quality were in cages where fish were fed with feeds with 41% of protein, then 33% and 25%. Fingerlings reached average body weight 56 g, 88.1 g, 116.7 g respectively. Food conversion rate was 3.34,1.84, 1.45 respectively.

АННОТАЦИЯ

В мае 2022 года сеголетки карпа (Cyprinus carpio) средней начальной массой тела 25 г была заселена в 9 садков (1м³ каждый) с нормой посадки 30 особей/садок в Каркидонском водохранилище, Узбекистан. В разных вариантах (в тройной повторности) использовали корма фермерского производства из одних и тех же ингредиентов с содержанием протеина 25, 33, 41 %. Норма кормления составляла 5 % биомассы рыб в каждом садке. Через 53 дня самые высокие темпы роста и качество корма были в садках, где рыбу кормили кормами с 41% протеина, затем с 33% и 25%. Сеголетки достигли средней массы тела 56 г, 88,1 г, 116,7 г соответственно. Кормовой коэффициент корма составил 3,34, 1,84, 1,45 соответственно.

Keywords: Common carp, Cyprinus carpio, fish feeding, cages, Uzbekistan.

Ключевые слова: Карп, Cyprinus carpio, кормление рыб, садки, Узбекистан.

Introduction

Aquaculture is one of a rapidly developed economics in recent years; it is one of the great producer and supplier of animal proteins for consumption. Total global aquaculture production reached 82,1 million tons/year including 51.3 million tons produced by freshwater aquaculture (FAO, 2020). Aquaculture importance as fish producer increase in continental regions.

Uzbekistan locates in arid deeply continental the Aral Sea basin and has poor natural fish resources and fully stocked rivers (Kamilov, 1973; Kamilov, 2003a). In such conditions, only aquaculture is the main producer of fish (Kamilov et al., 2004). In recent years, the country's aquaculture has developed and increased fish production from 6-9 thousand tons/year in 1994 – 2009 to more than 120 thousand tons in 2020. But aquaculture development was based mainly on development of semi-intensive pond aquaculture of carps: silver carp (Hypophthalmichthys molitrix) as main culture species and common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), and bighead carp (Hypophthalmichthys nobilis) as additional species (Kamilov, 2003b; Kamilov et al., 2018).

Fish ponds have occupied all land and water resource available in the country; there are no natural resources for further creation of earthen ponds. Besides, the production of pond polyculture supplies products to only one segment of fish products - mass fish. The remaining segments in the local market are not filled. The country needs to develop new technologies with significantly higher fish productivity on available water resources based on the principles of complex water use (Kamilov et al., 2004).

Intensive growing of fish in cages is one of the promising technologies taking into account quantity of reservoirs and lakes for residual water storages created in the country (Kamilov et al., 2017). Common carp, Cyprinus carpio, is very popular in local market. The modern production of carp in recent years is 10 – 15 thousand tons per year; that is not enough for market.

Cage culture can increase carp production, one of the main limitations is luck of knowledge of common carp feeding. The ‘farm-made’ feed strategy using local ingredients will increase rational use of local market products. In the heavily populated Fergana Valley (Uzbekistan), one of the reservoirs is the foothill Karkidon reservoir, where the water warms up to values favorable for carp growth (above 20^oC) from May to October. The goal of this research was to study common carp fingerlings growth using feeds made from the same ingredients but with the different protein level in cages.

Material and methods

The work was carried out in May-June 2022 in the Karkidon reservoir. The reservoir was constructed on the Isfaramsay River (Fergana Valley, the Syrdarya River basin, Uzbekistan), it has length of 5 km, width of about 5 km, maximum depths of up to 60 m, full volume of more than 200 million m³ and ‘dead volume’ (cannot be passed from reservoir) about 7 million m³.

During the field experiment, 9 floating fish cages (14 mm mesh), each with a volume of 1 m³, were installed in Karkidon reservoir. Common carp fingerlings uniform size was obtained from Namangan hatchery. Common carp fingerlings were stocked with density 30 fish/m³ to each cage. For one-week fingerlings were kept for adaptation to the conditions of cages, during this period they were fed at the rate of 3% of the fish biomass. At the beginning of the experiment (May 14th) the fish were weighed, the average individual weight (w₁, g) in each of the nine cages was determined as 25 g.  The experiment lasted 53 days.

The water temperature (as a limiting factor) was measured weekly in the surface water layer in the cages during the experiment.

Experimental fish were fed with three types of feeds with an estimated protein content of 25 %, 33 %, 41% (in triplicate), composed of the same ingredients, but in different proportions. Three diets were formulated for experiment. The percentage of ingredients in each diet is shown in Table 1. Protein level in fish meal was 55 % (according to quality certificate), in soybean meal (cake) - 45 %, in sunflower cake – 37 %. In wheat bran – 13 %.

For the production of feed, ingredients available on the local market were used: fish meal, soybean meal, wheat bran, sunflower cake, etc. The required amount of dry ingredients was weighed, the appropriate quantities for each diet were ground into flour, mixed, water and sunflower oil were added to bring the mixture to the consistency of minced meat, pelleted in grinder with mesh diameter 1 mm in electric meat grinder, the resulting strands were dried and crumbled to obtain granules that were used for 3 days. Pellets were dried, labeled and used for fish feeding.

Table 1.

Percentage of ingredients in diets (%)

The daily ratio of feeding was calculated for the mass of wet food as a percentage of the total common carp fingerlings biomass in cage. During the experiment, the daily ratio was 5 % in all cages.

A control catch was carried out every 10 days in all cages, during which the body weight of all fish was measured and averaged for feeding rate correction.

At the end of the experiment, the cages were fished, the average individual body weight of fish (w₂, g) was determined in each cage. The amount of feed used for fish feeding in each cage (q, g) was recorded.

The following indicators were calculated as parameters of fish growth:

• initial (w1) and final (w2) average body weight;
• body weight gain: dw (g) = w₂-w₁ (where w₁ is the initial average body weight of fish in the cage; w₂ is the final average body weight of fish in the cage);
• relative growth rate (g/day) = dw/t (where t is the duration of the experience in days);
• specific growth rate (SGR, specific growth rate): SGR (% per day) = [(ln w₂ –  ln w₁)/t] * 100 (where ‘ln’ is the natural logarithm).

The following indicators were calculated as parameters of feed quality:

• Feed conversion rate: FCR = the amount of feed intake (g) / wet body weight gain (g);
• Protein efficiency ratio (PURE, protein efficiency ratio): PER = increase in fish biomass (g) / amount of protein introduced with feed (g).

The statistical characteristics were calculated. The reliability was determined for the level of 5% (p < 0.05).

Results

Temperature regime. During the common carp fingerlings growing experiment, the water temperature inside of the cages and in the surrounding area was the same. From May 1^st to June 1^st, the average daily water temperature warmed up from 16°C to 23°C. During June the average daily water temperature was above 24°C.

Mortality. No fish died in all cages, so survival rate was 100 %.

Growth. Experimental fish grew in all cages, but they grew noticeably faster in cages fed with 41% protein (Table 2). Growth of average body weight during experiment is shown in fig. 1, where the difference in the growth rate of fish with different feeds is clearly visible. Average of initial weights, final weights, weight gains and other growth performance parameters of common carp that was fed with experimental diets are shown in Table 3.

Analysis of variance showed significant influence of such factor as difference in protein level (%) to such parameters as weight gain, relative growth rate, food conversion ratio and protein efficiency ratio which were significantly different (p > 0.05). As presented in Table 2, average weight gains (g), relative growth rates (g/day) and specific growth rate (%/day) were significantly (p<0.05) higher in cages with 41 % protein level, then 33 % protein level, and then 25 %.

During the experiment, the increase in body weight in cages with 41% feed was 3 times higher than with 25% feed. The fish growth rate was highest with 41% feed, then 33%, then 25%. The trend was the same for the specific growth rate of fish (Table 3).

The feed quality characteristics in the experiment are shown in Table 4. The analysis showed a clear relationship that the higher the protein content in the feed, the faster the fish grew. Thus, the food conversion rate for feed with 41% protein was the best and was only 1.45 on average. It should be noted that in the production of feeds a small list of ingredients available on the local market was used. In this case, the indicator turned out to be very acceptable for cage aquaculture. Feed efficiency indicators were quite good.

Common carp biomass growth. It should be noted that 750 g of carp seed stock were planted in each experimental cage. For 53 days of experiment in cages, total common carp biomass when fed with feed with 25% protein reached 1679 g (the increase was in biomass 929 g), with feed 33% protein - 2642.3 g (the increase was 1892.3 g), with feed 41% - 3505.7 g (the biomass growth was 2755.7 g).

Table 2.

Average common carp body weight growth (g) in cages with different type of feed

Table 3.

Common carp fingerling growth characteristics in the experiment by feed options (min – max/ mean)

Table 4.

Characteristics of experimental feeds quality in the rearing of common carp fingerlings (min – max / mean)

Figure 1. Growth pattern of common carp fingerlings on different experimental diets

Discussion

Feed sourcing and diet formulation for intensive aquaculture is a major trend in fisheries research (Goda et al., 2007; Stadtlander et al., 2013; Basri et al., 2015; Mustafa, 2021). In freshwater aquaculture, determinative share in running cost is expended on feeding the cultured fish and the most expensive component in fish feeds is cost of protein sources. Fish meal is the common and the most important dietary protein source in intensive aquaculture. Shortage and high cost of fish meal make fish feed expensive. Researchers pay great attention to the search for alternative sources of protein in fish feeds. Generally, the feed stuffs of animal origins are considered better alternative protein source if fish diets because of their higher content and other superior indispensable amino acids than the plant origins. Several animal protein sources were evaluated to formulate the diets for fish such as poultry by-product meal, meat and bone meal, snail and other invertebrate meal (Robinson, Li, 1998; Xue et al., 2003; Sogbesan et al., 2006; Hu et al., 2008; Li et al., 2009; Rawels et al., 2011). Main tendency is to partial replacement of fish meal with alternative protein source (Tacon, 1993; Tacon, Akiyama, 1997). The common carp has such peculiarity as variability to use different feeds including cereals, legumes, etc. (Scherbina, Gamygin, 2006).

An important aquaculture issue is fish feeding, in the solution of which the utilization of ingredients available in local market has a perspective. Ingredients we have used are widely common in different regions including Uzbekistan. Fishmeal is the main ingredient of aquaculture feeds in intensive aquaculture. Other ingredients are utilized by common carp rather effectively, as we can see in experiment.

Another aspect is the list of cultured fish species available in different regions. Currently, in Uzbekistan, for intensive aquaculture in the warm-water zone of the republic, there is the possibility of find fingerlings only of common carp, as well as African catfish (Clarias gariepinus). Common carp fingerlings can only be obtained from fish pond hatcheries in the Spring; so there would be yearlings (20 – 25 g). One of the issues is the adaptation of pond yearlings to cage conditions, including survival. As our experience has shown, carp yearlings quickly adapt to dense planting in cages, survival can be 100%.

Another promising for local intensive aquaculture aspect is high productivity. In pond semi-intensive aquaculture in local environments, productivity is 2500-3000 kg/ha or 0.1-0.2 kg/m³. In our experiment stocking density was 30 fish/m³; in way to grow table fish final productivity would be 30-40 kg/m³. That result will be very promising for private farmers which would like to enter aquaculture sector.

In the conditions of intensive aquaculture, the growth of fish is directly related to a higher protein content. (Hossain, Jauncey, 1989; Attala, Mikhail, 2008; Fa Kayode, Ugwumba, 2013). Our data clearly confirmed this trend for carp, especially since the food in all the experimental recipes was made from the same ingredients. In the experiment for 53 days, the planting material reached from 56 to 116 g. With feed with a protein content of 41%, the growth rate is much faster than that for carp in ponds.

Uzbekistan is situated in the south of the temperate climate and has extremal seasonality (very hot summer and rather cold winter)/ Local water resources are completely stocked for irrigation purposes; waters are mainly stocked in reservoirs and lakes for residual water storage (Kamilov, 2003). Those lentic water bodies are suitable for cage aquaculture. As our experiment has shown, common carp is promising fish species for cage culture in the country on the base of complex water use.

Our investigation indicated that progressive weight gain was reported in all treatments throughout the duration of experiment. That was the indication that the common carp fingerlings responded positively to all the diets. Our initial hypothesis was that feed with higher protein level will provide better fish growth and such feeds will have better quality.

Faturati et al. (1986), Akiwanda et al. (2002), Kurbanov et al (2015) have reported that feed with protein content 39-41% has preferable level of quality for feeding of African catfish. One of diet used in our experiments have 41 % of protein content; that diet showed the best fish growth and feed utilization characteristics also for common carp.

In Uzbekistan, with a developed pond polyculture of cyprinids, the production of feed for carp with a protein level of up to 25% has been established. Our experiment showed that the use of such feeds for feeding carp in cages also allows obtaining a certain growth of fish. This will allow the development of cage fish farming in regions with difficulties in obtaining high-protein feed for carp.

Feed conversion rate (FCR) is one of the most important indicators in fish farming. The feed with a protein content of 41% showed a very good level of quality (FCR - 1.45), and the quality of the feed with a protein content of 33% (1.84) was also quite high.

Fish feeding and the cost of feed is essential to the development of aquaculture. Estimation of the cost of ingredients and costs for the production of pellets in our case showed that the cost of feed with a protein content of 25% was 0.35 $/kg, 33% - 0.4 $/kg, 41% protein - 0.45 $/kg. Applying the feed coefficient obtained in the experiments, we determine that the share of feed in the cost of 1 kg of carp was: $ 0.63 for feed 41% protein, $ 0.72 for feed 33% protein, $ 1.16 for feed 25% protein. Of course, with the growth of carp, the indicator (feed ratio) will change, but the trend is obvious. For comparison, we indicate that the wholesale price of carp in the local market is $ 2.5. That, the advantage of using a high protein diet is clear.

Our experience has shown that common carp can be grown in floating cages in the environments of foothill Karkidon reservoir (and therefore, in the plain parts of Uzbekistan); using the ‘on farm’ feed preparation strategy, you can successfully grow table fish that is competitive in the market. We recommend calculating a recipe with a protein level of 33-41% protein (the higher the proportion of proteins, the better the growth of fish) for growing marketable fish, planting yearlings grown in the first year in pond polyculture of cyprinids in cages.

Conclusion

There is objective limit of specialized commercial feeds for global intensive culture of common carp because of relatively low price of that species. But in Uzbekistan, situated deeply in the biggest continent (Eurasia), common carp is very popular fish species in local market. From the result of our investigation, we can conclude that ‘on farm made’ feeds from common ingredients available in local market are promising for common carp culture in cages. At the same time, fishmeal remains the most important component in all the recipes that we have studied.

Acknowledgements

The studies were carried out within the framework of the project ‘Study of the population phenotypic diversity and adaptive potential of aquatic organisms for the theoretical substantiation of the development of fisheries in Uzbekistan,’ which is carried out by the Institute of Zoology of Uzbekistan Academy of Sciences. The authors are grateful to the Institute for providing all facilities and funding for this research.

References:

1. Akinwande, A.A., Ugwumba, A.A.A., Ugwumba, O.A. Effects of replacement of fish meal with maggot meal in the diets of Clarias gariepinus (Burchell, 1822) fingerlings. – Zoologist, 2002, 1. – pp. 41-49
2. Attala, R.F., Mikhail, S.K. Effect of replacement of fish meal protein with boiled full fat soybean weeds and dried algae on growth performance, nutrient utilization and some blood parameters of Nile tilapia (Oreochromis niloticus). – Egyptian journal of aquatic biology and fisheries, 2008, 12 (4). – pp. 41 – 61.
3. Basri, N. A., Shaleh, S. R. M., Matanjun, P., Noor, N. M., Shapawi, R. The potential of microalgae meal as an ingredient in the diets of early juvenile Pacific white shrimp (Litopenaeus vannamei). - Journal of Applied Phycology, 2015, 27(2). – pp. 857-863.
4. Fa Kayode, O.S., Ugwumba, A.A. Effects of replacement of fish meal with palm grub (Oryctes rhinoceros (Linnaeus, 1758)) meal on the growth of Clarias gariepinus (Burchell, 1822) and Heterobranchus longifilis (Valenciennes, 1840) fingerlings. – Journal of fisheries aquatic sciences, 2013, 8. – pp. 101 – 107.
5. FAO. 2020. The State of World Fisheries and Aquaculture 2020. In brief. Sustainability in action. Rome.
6. Faturati, E.O., Balogun, A.M., Ugwu, L.L.C. Nutrient utilization and growth responses of C. lazera fed different dietary protein levels. - Nigerian Journal of Applied Fish. Hydrobiology, 1986, 1. – pp. 41 - 45.
7. Goda, A.M., El-Haroun, E.R., Chowdhury, M.A. Effect of totally or partially replacing fish meal by alternative protein sources on growth of African catfish, Clarias gariepinus (Burchell. 1822) reared in concrete tanks. - Aquaculture Research, 2007, 38. – pp. 279-287.
8. Hossain, M.A., Jauncey, K. Nutritional evaluation of some Bangladeshi oil seed meals as partial substitutes for fish meal in the diets of common carp, Cyprinus carpio L. - Aquacult. Fish. Manage 1989, 20. – pp. 255-268.
9. Hu, M., Wang, Y., Wang, Q., Zhao, M., Xiong, B. et al. Replacement of fish meal by rendered animal protein ingredients with lysine and methionine supplementation to practical diets for gibel carp, Carassius auratus gibelio. – Aquaculture, 2008, 275. – pp. 260-265.
10. Kamilov, B.G. The use of irrigation systems for sustainable fish production: Uzbekistan. - In: Fisheries in irrigation systems of arid Asia. FAO Fisheries Technical Paper. N 430. Rome, FAO. 2003 (a).  pp. 115- 124.
11. Kamilov, B. Karimov B., Keyser D. The modern state of fisheries in the Republic of Uz-bekistan and its perspectives. – World aquaculture, 2004, vol. 35, N 1, pp. 8-13, 71.
12. Kamilov, B.G., Kurbanov, R.B., Salikhov, T.V. Ribovodstvo – razvedenie karpovikh rib v Uzbekistane (Piscie culture – cyprinids culture in Uzbekistan). Tashkent, Chinor ENK, 2003(b), 88 p. (in Russian)
13. Kamilov, B.G., Mirzayev, U.T., Mustafaeva, Z.A. Sadkovaya akvakultura – perspetivnaya Sistema razvedeniya rib v Uzbekistane. (Cage aquaculture – promising system of fish culture in Uzbekistan). Tashkent, Navruz, 2017. – 63 p. (in Russian).
14. Kamilov, B.G. Yuldashov, M.A., Soativ, U.R., Khalilov, I.I. Presnodonaya akvakultura Uzbekistana. (Freshwater aquaculture in Uzbekistan). Tashkent, GOLD-PRINT NASHR, 2018. – 156 p. (in Russian).
15. Kurbanov, A.R., Milusheva, R.Yu., Rashidova, S.Sh., Kamilov, B.G. Effect of replacement of fish meal with silkworm (Bombyx mori) pupa protein on the growth of Clarias gariepinus fingerling. - International Journal of Fisheries and Aquatic Studies, 2015, 2(6). – pp.  25-27. http://fisheriesjournal.com/vol2issue6/vol2issue6a.html.
16. Li, K., Wang, Y., Zheng, Z.X., Jiang, R.L., Xie, N.X. et al. Replacing fish meal with rendered animal protein ingredients in diets for Malabar grouper, Epinephelus malabaricus, reared in net cages. – Journal of World Aquaculture Society 2009; 40:67-75.
17. Mustafa, A. M. Effects of replacement of fishmeal with other alternative protein sources in the feed on hydrochemical and technological parameters in African catfish (Clarias gariepinus). AACL Bioflux, 2021, 14 (3). – pp.1524-1533.