Abstract
Labeo rohita, Gibelion catla, Cirrhinus mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix were grown together for 365 days in triplicate ponds. Six iso-caloric feeds having varying protein levels i.e. 22, 24, 26, 28, 30 and 32% were prepared and supplemented to fish at 2% fish weight daily. Significantly, higher final average weight (793 ± 197 g) and total length gain (398 ± 40 mm) was recorded for Ctenopharyndodon idella. Net fish yield enhanced as the level of digestible protein (DP) in the supplementary diets increased and plateaued at 28% DP level, thereafter significant reduction (P<0.05) in fish weight increments was experienced at any surplus protein level. Among the supplementary feeds, 28% DP level resulted in maximum net fish yield (4304 ± 33 kg ha-1 year-1) and a significantly higher overall nitrogen conversion ratio (NCR) of 1:5.2 ± 0.14. Higher level of DP in supplementary feeds resulted in reduced fish growth.
Key Words: Chinese carps, Composite culture, Condition factor, Indian major carps, Supplemental feed
Introduction
Major and Chinese carps are economically important commercially grown fish species in Pakistan. Labeo rohita is intensively cultured and consumed in Asian countries (Ahmed et al., 2015 ▶), Gibelion catla have good market potential and taste, Cirrhinus mrigala being bottom feeder is grown under composite culture conditions to exploit nutrients that settle down to the bottom. Ctenopharyngodon idella has higher growth potential and alone contributes 18% of the total fish production in China (He et al., 2015 ▶) and Hypophthalmichthys molitrix has good aptitude to the acceptability of supplementary diets (Ashraf et al., 2011 ▶).
Semi-intensive composite culture system results in low cost fish production thus contributing to food security, especially in developing countries (Mataka and Kangombe, 2007 ▶). Major and Chinese carps are well suited for pond culture as they occupy different feeding niches and hence utilize all the available food present in pond water (Noman et al., 2011 ▶). Protein deficiency in fish diet hinders growth as fish will start utilizing its own body proteins to meet its maintenance demands. Regular intake of protein is required by the fish for metabolic processes and tissue repair (Singh et al., 2008 ▶). Thus optimization of protein in supplementary fish feeds is essential for making the pond fish production a prospective food industry in Pakistan.
Materials and Methods
A 365 day experiment was conducted to optimize protein levels in fish diet. Carps i.e. Labeo rohita, Gibelion catla, Cirrhinus mrigala, Ctenopharyngodon idella and Hypophthalmichthyes molitrix were taken as experimental animal. All the five fish species were reared together in 18 earthen ponds having equal dimensions of 120 m2. Fingerlings of five fish species were stocked at a density of 27:10:10:07:13 into six triplicate groups in ponds. Fish from each pond were sampled on a fortnightly basis using drag net to record growth parameters viz. wet weights and total lengths, condition factor and nitrogen conversion ratios (NCR). At the end of the experiment, total harvested fish of all the five fish species were weighed to calculate the net fish yield under different treatments.
Six supplementary iso-caloric feeds (3 mm pellets) having digestible energy of 2500 kcal kg-1 at varying protein levels of 22, 24, 26, 28, 30 and 32% were prepared (Table 1) in the laboratory and fed to the fish at 2% of their wet body weight on a daily basis. Proximate composition i.e. moisture, crude protein, total fats, total ash and carbohydrates of supplementary feeds were determined (Association of Official Analytical Chemists, 2006 ▶).
Table 1.
Formulation and proximate composition of supplementary feeds at varying digestible protein levels
| Ingredients | 22% DP | 24% DP | 26% DP | 28% DP | 30% DP | 32% DP |
|---|---|---|---|---|---|---|
| Wheat flour | 13 | 13 | 13 | 13 | 9 | 11 |
| Starch | 2 | 2 | 2 | 2 | 2 | 2 |
| Rice polish | 20 | 18 | 12.5 | 5 | 3 | 0.5 |
| Wheat bran | 15 | 9.5 | 5.5 | 5 | 2 | 0.5 |
| Canola meal | 1 | 5 | 10 | 12.5 | 16 | 25 |
| Rape seed meal | 1 | 1 | 5 | 4 | 9 | 7 |
| Sunflower meal | 0.5 | 2.5 | 4 | 5 | 7.5 | 10 |
| Corn gluten 30% | 22 | 22 | 21 | 22 | 18 | 5 |
| Soybean meal | 0.5 | 2 | 2 | 6 | 7 | 12 |
| Fish meal | 20 | 20 | 20 | 20 | 20 | 20 |
| DCP | 1.5 | 1.5 | 1.5 | 1 | 1 | 1 |
| Soya oil | 1 | 1 | 1 | 2 | 3 | 3.5 |
| Vitamin and mineral mixture | 2.5 | 2.5 | 2.5 | 2.5 | 2.5 | 2.5 |
| Proximate composition (%) | ||||||
| Moisture | 7.30 | 7.04 | 6.85 | 6.86 | 6.90 | 6.89 |
| Crude protein | 22.24 | 24.00 | 26.08 | 28.17 | 30.00 | 32.00 |
| Total fats | 7.25 | 7.43 | 7.48 | 7.37 | 7.91 | 8.33 |
| Total ash | 7.13 | 6.92 | 6.66 | 6.19 | 6.29 | 5.32 |
| Carbohydrates | 56.08 | 54.61 | 52.93 | 51.41 | 48.90 | 47.46 |
| Energy (kcal/kg) | 2517 | 2530 | 2500 | 2515 | 2525 | 2513 |
Each kg of vitamin-mineral mixture contains: Vitamin A 3,000,000 I.U.; Vitamin E 6000 I.U.; Vitamin B1 600 mg; Nicotinic acid 12,000 mg; Calcium d. pantothenate 2400 mg; Vitamin B12 8 mg; Biotin 10 mg; Dl-Methionine 30,000 mg; B.H.T. 12,500 mg; Zinc sulphate 48,000 mg; Copper sulphate 6,000 mg; Vitamin D3 6000000 I.U.; Vitamin K3 600 mg; Vitamin B2 1400 mg; Vitamin B6 800 mg; Folic acid 300 mg; Choline chloride 50% 160000 mg; L-Lysine 15000 mg; Manganese sulphate 51600 mg; Ferrous sulphate 40000 mg; Potassium iodide 400 mg. Carbohydrates were calculated by difference as 100 - (protein + lipid + ash + moisture). Energy was determined by Bomb Calorimeter (Parr Instrument Company Moline, USA)
Condition factor, NCR and survival rate of all the experimental fish species were calculated following (Carlander, 1970 ▶). Live food in ponds was calculated through evaporation method (Javed, 1988 ▶).
Statistical analysis
Obtained data were subjected to statistical analysis through analysis of variance (ANOVA) and the mean values were compared for statistical differences through Tukey’s Newman-Keul’s test using software STATISTIX 8.1 (USA).
Results
Among the five fish species, C. idella showed significantly higher final weight and total length gains of 793 ± 197 g and 398 ± 40 mm, respectively. The overall performance of five fish species under different treatments varied significantly and followed the order T3>T4>T2>T5>T1≥T6 (Table 2). The net yield of all five fish species was significantly higher due to 28% DP level. During present study, planktonic biomass was significantly higher (48 ± 20 mg L-1) due to 32% DP (T6). Supplementary feed at 28% DP (T4) level showed significantly higher overall NCR values of 1:5.2 ± 0.14. However, NCR value of 1:4.0 ± 0.07 was significantly lower due to 32% DP (T6). Fish did not suffer any mortality throughout the experimental duration.
Table 2.
Comparison of growth indices of five fish species under composite semi-intensive pond culture conditions
| Fish species | Initial average weight (g) |
Final average weight (g) |
Initial average total length (mm) |
Final average total length (mm) |
Condition factor (K) |
|---|---|---|---|---|---|
| Labeo rohita | 13 ± 2.0c | 677 ± 165c | 91 ± 5.6c | 383 ± 42c | 1.2 ± 0.13c |
| Gibelion catla | 07 ± 0.3e | 406 ± 105e | 64 ± 2.9e | 321 ± 23d | 1.2 ± 0.15c |
| Cirrhinus mrigala | 21 ± 0.9b | 764 ± 150b | 116 ± 5.1b | 389 ± 39b | 1.3 ± 0.16b |
| Ctenopharyngodon idella | 08 ± 0.5d | 793 ± 197a | 65 ± 3.1d | 398 ± 40a | 1.2 ± 0.13c |
| Hypophthalmichthys molitrix | 23 ± 1.1a | 478 ± 135d | 120 ± 4.9a | 320 ± 29d | 1.4 ± 0.12a |
(Means±SD) values with different alphabets in the same column are significantly different (P<0.05)
Discussion
Growth performance of all the five fish species showed significant variability due to various digestible protein (DP) levels in the supplementary diets. Among the five fish species, C. idella showed significantly higher final weight and total length gains of 793 ± 197 g and 398 ± 40 mm, respectively. This variability among different fish species for their responses towards different protein levels was attributed to their diversified feeding habits (Yaqoob et al., 2010 ▶). When reared in poultry waste recycled ponds, C. idella has been reported a major contributor towards total fish production as compared to H. molitrix and C. carpio (Singh et al., 2008 ▶). However, there existed some sort of competition for food procurement between G. catla and H. molitrix, and that is the reason why the growth performance of these two species suffered during present study. Tabinda and Ayub (2010) ▶ also reported similar competing trend for food between these two species.
The net fish yield increased significantly and attained a peak at 28% DP. However, further increase in DP i.e. beyond 28% did not improve fish growth, but caused a decline in net yield. Such trend observed showed channelization of more energy towards catabolism of excess proteins (Siddiqui and Khan, 2009 ▶). This may also have resulted due to catabolism of excess proteins, beyond optimum, a condition to produce and eliminate a lot of ammonia by the fish (Kim and Lee, 2005 ▶).
Supplementary feed at 28% DP (T4) level showed significantly higher overall NCR values of 1:5.2 ± 0.14. However, NCR value of 1:4.0 ± 0.07 was significantly lower due to 32% DP (T6). Significantly lower NCR attained by the fish under T6 might be attributed to the stress imparted on the fish fed higher protein level in supplementary diets. Naz et al. (2008) ▶ also observed significantly lower NCR for stressed fish as compared to non-stressed fish. Zero mortality across all the treatments during this study showed conduciveness of aquatic environment for fish growth.
Ctenopharyngodon idella showed highest growth potential and a better inclination towards the acceptability of artificial diets. Gibelion catla and Hypophthalmichthyes molitrix, were found to be in competition for access to food. Net fish yield increased as the level of DP in supplementary diets increased and attained a plateau at 28% DP level. However, any surplus protein level beyond 28% hindered fish growth. Un-eaten feed recycle in pond ecosystem to contribute towards planktonic productivity. Fish reared under semi-intensive culture conditions had lower protein requirements due to the availability of natural food (plankton) as compared to fish reared under intensive culture conditions. Higher level of DP in supplementary feeds resulted in reduced fish growth.
Conflict of interest
Authors declare no conflict of interest.
References
- Ahmed, MK, Shaheen, N, Islam, MS, Habibullah-al-Mamun, M, Islam, S, Mohiduzzaman, M, Bhattacharjee, L. Dietary intake of trace elements from highly consumed cultured fish (Labeo rohita, Pangasius pangasius and Oreochromis mossambicus) and human health risk implications in Bangladesh. Chemosphere. 2015;128:284–292. doi: 10.1016/j.chemosphere.2015.02.016. [DOI] [PubMed] [Google Scholar]
- Ashraf, M, Zafar, A, Rauf, A, Mehboob, S, Qureshi, NA. Nutritional values of wild and cultivated silver carp (Hypophthalmichthys molitrix) and grass carp (Ctenopharyngodon idella) Int. J. Agric. Biol. 2011;13:210–214. [Google Scholar]
- Association of Official Analytical Chemists. Official methods of analysis. 18th Edn. Washington, D. C: Association of Official Analytical Chemists International; 2006. p. 1727. [Google Scholar]
- Carlander, D. Handbook of freshwater fishery biology. 3rd Edn. Vol. 1. Lowa, USA: The Lowa State University Press; 1970. p. 104. [Google Scholar]
- He, L, Pei, Y, Jiang, Y, Li, Y, Liao, L, Zhu, Z, Wang, Y. Global gene expression patterns of grass carp following compensatory growth. BMC Genomics. 2015;16:184–201. doi: 10.1186/s12864-015-1427-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Javed, M, 1988 . Growth performance and meat quality of major carps as influenced by pond fertilization and feed supplementation. Ph.D. Thesis. Faisalabad, Pakistan: Department of Zoology and Fisheries, University of Agriculture; p. 67. [Google Scholar]
- Kim, LO, Lee, SM. Effect of the dietary protein and lipid levels on growth and body composition of bagrid catfish, Pseudobagrus fulvidraco. Aquaculture. 2005;243:323–329. [Google Scholar]
- Mataka, L, Kangombe, J. Effect of substitution of maize bran with chicken manure in semi-intensive pond culture of Tilapia rendalli (Boulenger) Aquacult. Res. 2007;38:940–946. [Google Scholar]
- Naz, S, Javed, M, Hayat, S, Abdullah, S, Bilal, M, Shaukat, T. Long term effects of lead (pb) toxicity on the growth performance, nitrogen conversion ratio and yield of major carps. Pak. J. Agric. Sci. 2008;45:53–58. [Google Scholar]
- Noman, M, Ashraf, M, Abbas, S, Ahmad, I, Naeem, M, Hafeez-ur-rehman, M. Growth performance of common carp (Cyprinus carpio) in response to organic fertilizers and supplementary feed. Greener J. Agric. Sci. 2011;1:32–40. [Google Scholar]
- Siddiqui, TQ, Khan, MA. Effect of dietary protein levels on growth, feed utilization, protein retention efficiency and body composition of young Heteropneustes fossilis (Bloch) Fish Physiol. Biochem. 2009;35:479–488. doi: 10.1007/s10695-008-9273-7. [DOI] [PubMed] [Google Scholar]
- Singh, RK, Chavan, SL, Desai, AS, Khandagale, PA. Influence of dietary protein levels and water temperature on growth, body composition and nutrient utilization of Cirrhinus mrigala (Hamilton, 1822) fry. J. Therm. Biol. 2008;33:20–26. [Google Scholar]
- Tabinda, AB, Ayub, M. Effect of high phosphate fertilization rate on pond phosphate concentrations, chlorophyll a, and fish growth in carp polyculture. Aquacult. Int. 2010;18:285–301. [Google Scholar]
- Yaqoob, M, Ali, MR, Mehmood, S. Comparison of growth performance of major and Chinese carps fed on floating and sinking pelleted supplementary feeds in ponds. Pak. J. Zool. 2010;42:765–769. [Google Scholar]