COST EFFECTIVENESS AND INFLUENCE OF FEED TYPES ON THE REPRODUCTIVE OUTPUT OF TILAPIA REARED IN EARTH PONDS *ANSA, E.J. African Regional Aquaculture Centre (ARAC), P.M.B. 5122, Port Harcourt, Nigeria. ebinimi@gmail.com HART, A.I. & OKOSIMIEMA, I. Department of Animal and Environmental Biology, University of Port Harcourt, P.M.B. 5323, Port Harcourt, Nigeria BEKIBELE, D.O. & OPARA, J.Y. African Regional Aquaculture Centre (ARAC), P.M.B. 5122, Port Harcourt, Nigeria ABSTRACT Fish farmers in Nigeria have successfully bred catfish on a commercial scale but are somewhat reluctant to grow tilapia because of uncertainties on the output and requirements for hatchery production and profitability of the business. In response to this need, trials were carried out in experimental earthen ponds at the African Regional Aquaculture Centre (ARAC), Aluu, Rivers State, Nigeria to determine the cost-effectiveness of two diets labelled ‘Treatment A’ (an imported commercial feed (45% crude protein) and ‘Treatment B’ locally formulated tilapia diet (35% crude protein)). The treatments were replicated three times in a complete randomized design. Each pond was stocked with 15 pairs of adult tilapia, Oreochromis niloticus with male: female ratio of 1:1 and fed twice daily at 5% body weight. Ponds also received manure occasionally to boost phytoplankton production. Ponds were not aerated. The corresponding output of tilapia fingerlings for each treatment was determined at the end of 60 day rearing period. There were no significant differences between daily growth rate (DGR), specific growth rate (SGR) and survival in the two treatments (P > 0.5). However, more fry, fingerlings and sub-adults were produced in Treatment A than Treatment B ponds. On the contrary, incidence costs were lower in ponds receiving locally formulated feed (17.6) than ponds receiving imported feeds (23.7). This indicates that in the long run it would be more cost-effective for the tilapia farmer to use locally manufactured feed than imported feeds in fingerling production. INTRODUCTION • Nile tilapia (Oreochromis niloticus) – Fig. 1, native to Africa but successfully introduced across the globe (FAO, 2010) • Asian countries like China, Thailand, Philippines and Indonesia top the list as major producers of tilapia (Guerrero, 2002) • Despite this feat in Asia, many fish farmers in African countries are yet to tap into the commercial production of tilapia • Egypt is an exception as the highest producer of tilapia on the Continent (Josupeit, 2005) • In Nigeria, commercial catfish farming is well established; but farming tilapia is still a challenge to many farmers • One of the issues expressed by fish farmers in Southern Nigeria is the modality for production of healthy fingerlings at reasonable costs; since high costs of catfish feeds have caused the exit of some farmers from catfish production business • Due to uncertainties on the output and requirements for hatchery production and profitability of the business, many farmers are reluctant to embark on tilapia farming businesses for fingerling production or for food. • In response to these needs, an experiment was conducted • to determine cost-effectiveness of two formulated diets on tilapia • to evaluate the number of fry and fingerlings produced Special thanks to AWARD www.awardfellowships.org for full sponsorship of my trip and participation at the AASA 2013 Conference in Stellenbosch, South Africa. Fig. 1: Nile tilapia Oreochromis niloticus MATERIALS AND METHODS • Six 50 m 2 earthen ponds at the African Regional Aquaculture Centre (ARAC), Aluu, Rivers State, Nigeria were prepared, screened and used in growing tilapia (Fig 2) • Each pond was stocked with 15 pairs of male and female Oreochromis niloticus (Nile tilapia) • Morphometric measurements were taken using a measuring board to determine total length in cm; weight (g) was measured using ‘Scout Pro SPE601’ balance • Two diets were applied to the ponds – Imported commercial fish feed (45% C.P.) and locally produced ARAC tilapia fish feed (35% C.P.) each treatment was replicated three times • Fish were fed twice daily at 5% body weight • Ponds were fertilized with pig manure at 21 days and 45 days into the experiment at a rate of 7.5 kg per pond • Water quality parameters (Dissolved oxygen (D.O.), pH, temperature, alkalinity) were monitored fortnightly • Percent survival, DGR and SGR of brood-stock were determined • Number of fingerlings and fry produced under each treatment were counted manually and recorded • Incidence cost (IC) was calculated using the formula (Vince le, 1969): IC = Cost of feed/Weight of fish produced • t-test used to determine statistical significance of results Fig. 2: Screened tilapia breeding pond Table 1: Initial and final mean weight and length data of tilapia broodstock fed two types of feed in 60 days Imported Feed Local Feed Initial mean weight (g) 187.3 139.3 Final mean weight (g) 206.6 159.3 Weight gain (g) 19.3 19.8 Initial Total Length (cm) 17.2 15.68 Final Total Length (cm) 21.9 20.9 2 3 4 5 6 7 8 9 Dissolved Oxygen mg/l Treatment A Dissolved Oxygen mg/l Treatment B 5.8 5.9 6 6.1 6.2 6.3 6.4 pH Treatment A pH Treatment B 20 22 24 26 28 30 32 Temperature °C Treatment A Temperature °C Treatment B 20 25 30 35 40 45 50 55 Alkalinity Treatment A Alkalinity Treatment B RESULTS • Physico-chemistry: Figs 3, 4, 5 & 6 (P > 0.05) • Brood-stock data (mean weight and length data): Table 1 • SGR, DGR, Survival rates: Table 2 • Mean weight and number of fish harvested: Table 3 • Selling price, Incidence Cost, Income: Tables 4, 5 & 6 Fig. 3: D. O. values for ponds receiving imported (A) and local (B) feeds Fig. 4: pH values for ponds receiving imported (A) and local (B) feeds Fig. 5: Temperature values for ponds receiving imported (A) and local (B) feeds Fig. 6: Alkalinity for ponds receiving imported (A) and local (B) feeds Table 2: Growth and survival rates of tilapia broodstock fed two types of feed in 60 days Imported Feed Local Feed Specific Growth Rate (SGR) 1.5 1.02 Daily Growth Rate (DGR) 0.32 0.33 % Survival 93 97 Table 3: Mean weight and number of tilapia harvested after sixty days Number of fish harvested after 60 days Mean weight (g) Imported feed Local feed Fry 0.08 6930 4620 Post fry 2.59 5390 2820 Fingerlings 38.91 850 725 Post fingerlings 25.07 375 282 Sub-adult 128.04 140 110 Adult 182.95 28 29 Table 4: Selling price of fish Number of fish sold Prices N Imported Feed (A) Local feed (B) Price/ fish Total Price (A) Total Price (B) FINGERLINGS 800 715 10 8,000 7,150 POST- FINGERLINGS 350 260 30 10,500 7,800 SUB-ADULTS 130 100 50 6,500 5,000 TOTAL 25,000 19,950 Exchange rate USD$ 1 = N 159.00 Table 5: Incidence Cost Analysis Cost of feeding N Weight of fish (g) Incidence Cost (IC) Imported feed 4,900 206.6 23.7 Local feed 2,800 159.3 17.6 DISCUSSION • Water quality was within the desirable range for culture of tilapia (Boyd, 1981; Thomas and Leonard, 1995) with no statistically significant variation between treatments •Growth response was higher in tilapia fed imported feeds than tilapia fed local feeds; possibly due to higher level of crude protein in the imported feed • The difference recorded in the yield of tilapia fingerlings and average weight gain were not significantly different between treatments (P > 0.05). The variation in the yield of fingerlings may be as a result of the mean weight of fish stocked. Fecundity of fish is known to increase with increase in fish weight. •Economically however, the incidence costs obtained for both feed types indicate that it is more profitable to use local feeds in tilapia fingerling production business •This is a welcome development as farmers will spend less in the purchase of local produced fish feeds and also make more profits in the long run. •In future, a retrial of this experiment is proposed using adults that fall within the same size range Table 6: Recurrent expenditure and income profile RECURRENT COSTS N TREATMENT A TREATMENT B Agricultural lime 1,000 1,000 Water pump hire 500 500 Fuel 250 250 Labour 2,500 2,500 14kg Imported feeds @ N 350/kg 4,900 - 14kg Local feeds @ N 200/kg - 2,800 TOTAL REC. COSTS (A) N 6,650 N 4550 INCOME FROM FISH SALE (B) N 25,000 N 19,950 INCOME = B – A N 18,350 N 15,400 CONCLUSION Profitability is the key to success in any business and fish farming business is not an exception. This study which compared effects of feed types on the reproductive output of tilapia and the cost-effectiveness of the feeds indicates that less expensive locally manufactured feed is a beter option for fish farmers to attain good number of fingerlings and increased income in the long run. View publication stats View publication stats