1. Introduction
In Nigeria today, despite the significant investment in commercial agriculture by the government, aid agencies, multilateral organizations and individuals, livestock production has not succeeded in meeting the protein demands in the country (Oluwatayo and Adedeji, 2019) [1]. The increasing human population in the country has indicated that the conventional forms of livestock production and artisanal fisheries which have been over-exploited will not be sufficient to solve the growing protein demand in Nigeria (Umaru et al., 2016) [2]. There is an urgent need to evolve holistic and innovative strategies to address the lack of food security in the country, especially protein intake (Ubesie and Ibeziakor, 2012) [3]. This is where fish culture, particularly the culture of African Sharp tooth Catfish (Clarias gariepinus) holds much promise.
African Sharp tooth Catfish (Clarias gariepinus) is one of the most important cultured fish in developing countries like Nigeria, Cameroon, Democratic Republic of Congo, Tanzania, and Uganda (Limbu, 2019) [4]. The preference for this freshwater fish could be attributed to its fast growth rate, resistance to diseases, ability to withstand harsh environmental changes and good market value (Amisah et al., 2009) [5] and (Farahiyah et al., 2016) [6]. Unfortunately, the effective production of Clarias gariepinus in Nigeria has been hampered by the high cost of imported feed and the non-availability of affordable locally made high-quality fish feeds (Yakubu et al., 2015) [7]. Fish feeds in sustainable fish culture system account for 40 to 60% total production cost and need to be supplied in the right proportions with proper nutritional composition as it determines the effectiveness of fish growth and survival rate (Toutou et al., 2018) [8] and (Dorothy et al., 2018) [9].
The quest to provide adequate feed have been high and in an attempt to provide cheaper, affordable and available feed for Clarias gariepinus which will serve as an alternative to the expensive imported commercial feeds, several local fish feeds have been formulated from different sources leading to the emergence and proliferation of many fish feeds industries in Nigeria (Mustapha et al., 2014) [10]. As a result of these intensified efforts, the Nigerian markets are littered with an assortment of imported and locally manufactured catfish feed brands, thereby leaving fish farmers with different options (Agokei et al., 2010) [11] (Mustapha et al., 2014) [10]. Unfortunately, in terms of control over the feed components and quality, there is lack of legislation and regulations in Nigeria, and farmers are left with no option than to depend on labelled information provided by the feed manufacturers on feed composition and growth performance without any form of authentication since a very limited study on proximate composition of standard feed and its growth response on African Catfish has been reported in Nigeria despite the significant investment in aquaculture in the country (Ajayi et al., 2016) [12] and (Umaru et al., 2016) [2]
It is against this backdrop, that this study was carried out to evaluate the growth performance of African Catfish (Clarias gariepinus) fed with different standard feed. This study provides baseline information that will assist farmers, regulatory agencies, and other stakeholders in the fisheries industry.
2. Materials and Methods
2.1. Collection of experimental organism and test feeds
The study was conducted at the Animal house unit of the Department of Animal and Environmental Biology, University of Port Harcourt, Rivers State, Nigeria. The experimental fish used was Clarias gariepinus. A total of 220 post fingerlings of Clarias gariepinus with an initial body weight of 5.5 ± 0.0 grams were procured from the Africa Regional Aquaculture Centre (ARAC), Aluu Port Harcourt, Rivers State and transported to the experimental site in the early hours of the day in an open plastic bucket covered with nylon net. At the experimental site, they were immediately transferred into holding tanks. The experimental organisms were acclimatized for 14 days before the commencement of the experiment. The holding tanks were cleaned, and the water renewed once in three days (Odioko et al., 2016) [13] . Three standard commercial feeds namely Coppens, Vital, and Multifeed of 2 mm in size were procured from Animal Affairs Limited, a commercial feed dealer in Port Harcourt.
2.2. Experimental design
This experiment lasted for twelve weeks (3 months). A total number of one hundred and eighty (180) Clarias gariepinus were used and evenly distributed, twenty (20) per treatment (T1 for Coppens, T2 for Vital, and T3 for Multifeeds), with three replicates of each. Plastic Aquaria with a dimension of 0.50 x 0.38 x 30 m were used for the experiment. The test organisms were not fed for 24 hours before the commencement of the feeding trial. The initial mean weight and length were measured with the aid of a digital weighing balance and metre rule respectively. The test organisms in the different aquaria were fed twice daily between the hours of 9 am and 5 pm at 5% of their body weights. The water quality of the aquaria was maintained by siphoning fecal waste and leftover feds daily. The water in the plastic aquaria was replaced with clean water sourced from borehole every three days. The aquaria were covered with nets to prevent the test organisms from jumping out. This experimental design was completely randomized.
2.3 Measurement of growth parameters
The initial weight of the individual fish at the starting of the experiment and final body weight and length were determined with the aid of a digital weighing balance and metre rule. These body weight and length measurements were done every week to monitor the differences in weight gain and length increase. Generally, the growth performance of the fish was determined using the following mathematical expressions:
2.4. Water quality parameters
Water quality parameters were monitored for temperature, pH and Dissolved Oxygen (DO) on weekly basis at 8 am with the aid of mercury-in-glass thermometer for temperature in degree Celsius (oC) and pocket-sized pH metre (MilwaukeepH 600 Tester Kit) was used in the determination of water pH, while Dissolved Oxygen (DO) present in the water was measured with the aid of portable Dissolved Oxygen meter (Milwaukee MW 600).
2.5. Proximate analysis and analytical procedure
The proximate analysis of the trail feeds was conducted at the Biotechnology Laboratory of Rivers State University, in an airtight environment. The analytical procedure used to analyze the nutritional composition of the different standard (commercial) feeds were based on the (A.O.A.C, 2000) [14] standard procedure for proximate analysis to obtain an accurate result for Moisture, Crude protein, Ether Extract, Fibre and Ash.
2.6. Statistical analysis
All data were subjected to statistical analysis to determine the variation in the different parameters measured during this study. The one-way analysis of variance (ANOVA) was used to determine if there were significant differences (P = 05) from the data obtained from the different parameters. To determine the differences within means, Duncan’s multiple range tests was used. All statistics were done using the Statistical Package for Social Sciences (SPSS) version 21.
3. Results
The results for the measured length revealed a significant difference (P = 05) in final length with T1 recording the highest value (22.81 ± 0.05 cm), followed by T3 (20.72 ± 0.28 cm) and T2 (18.75 ± 0.49 cm). The analysis of final weight gained showed that T1 recorded (83.93 ± 1.29 g), T3 (78.8 ± 0.54 g) and T2 (65.93 ± 0.20 g), the differences in weight was significant (P = 05). Feed conversion ratio (FCR) recorded were T1 (18.74 ± 0.13), T2 (19.18 ± 0.35) and T3 (19.51 ± 0.73). The result for specific growth rate (SGR) showed that T1 recorded (4.53 ± 0.02 g/day), T3 (4.46 ± 0.01 g/day) and T2 (4.28 ± 0.00 g/day). The result of mortality rate showed that T1 recorded (4.00 ± 1.00), T2 (6.00 ± 1.73) and T3 (3.67 ± 1.53) and survival rate for T1 (80.00 ± 5.00), T2 (70.00 ± 8.66) while T3 recorded (81.67 ± 7.66). There was no significant difference (P ≠ 05) in the survival rate, mortality rate and feed conversion ratio across the treatment groups as shown in Table 1.
The results for the proximate composition of the standard feeds used are presented in Table 2. The mean proximate composition of the feed used as shown in Table 2, showed that Coppens (T1) contained a higher crude protein with mean value 48.50 ± 1.02 than the other Treatments, T3 (Multifeed) with 47.30 ± 0.29 and T2 (Vital Feed) with the least value of 45.60 ± 0.29. The mean values of ether extract followed the same pattern, with T1 having the highest value (12.50 ± 0.58), T3 (8.00 ± 0.12) and T2 (1.50 ± 0.58). The mean values of crude fibre showed that T2 had the highest mean value (3.00 ± 0.12), followed by T3 mean value (2.4 ± 0.17) and T1 recorded the least value (1.5 ± 0.06). The mean values of moisture content showed that T3 had (7.90 ± 0.17), followed by T2 (7.70 ± 0.23), while T1 (7.30 ± 0.23) recorded the least. The results of the mean proximate analysis for the three treatments showed there was a significant difference (P = 05) between the macronutrients composition of the different feeds.
The results for the monitored water parameters are shown in Table 3. The analyzed results revealed that T3 (Multifeed) recorded the highest mean value (24.84 ± 0.15 oC) in terms of water temperature, followed by T2 (Vital Feed) with (24.65 ± 0.13oC), while T1 (Coppens) had the least value (24.59 ± 0.39oC). The mean value of Dissolved Oxygen for T3 was (2.73 ± 0.46) being the highest, followed by T1 with (2.52 ± 0.60), T2 recorded the least Dissolved Oxygen with 2.51 ± 0.45. Mean values for pH shows that T1 had (7.53 ± 0.18), T2 (7.39 ± 0.14) while T3 (7.53 ± 0.33). The results in Table 3 showed there was no statistically significant difference (P ≠ 05) in all the physicochemical parameters of water monitored during the experiment.
4. Discussion
Fish feed is one of the most vital agro-inputs used in fish culture, which has a direct effect on the growth performance and survival rate of fishes (Putra et al., 2017) [15]. From the result of growth parameters of African catfish (Clarias gariepinus) fed with different standard feed, as shown in Table 1, fish fed with T1 (Coppens), gave the best growth performance in terms of Weight Gain (WG), Length Gain (LG), Final Weight (FW), Final Length (FL), Feed Conversion Ratio (FCR) and Specific Growth Rate (SGR). This was followed by the group fed with T3 (Multifeed), and the least performance was recorded among group fed T2 (Vital feed). This finding was in consonant with the findings reported by Umaru et al (2016) [2] and Agokei et al (2010) [11] on feeding trial of Clarias gariepinus. The differences in growth performance amongst treatments could be attributed to the differences in the nutritional composition of the feed used (Mustapha et al., 2014) [10]. The result of proximate analysis of the feed shown in Table 2, revealed that Coppens had more of the macronutrients than Multifeed and Vital feed, and this nutrient availability particularly crude protein may have given corresponding growth response (Ajayi et al., 2016) [12] . Although, the value of Feed Conversion Ratio (FCR) was generally high in all the treatment groups which exceeded 2, recommended as the maximum value for FCR by Houlihan et al. (2001) [16] since feed conversion ratio serves as a parameter to predict the efficiency of the feed used in an experimental trial.
The physicochemical parameters obtained in this study as shown in Table 3, revealed that water temperature and pH were within the appropriate range required for efficient catfish growth under cultured system (Musiba et al., 2014) [17]. The values of Dissolved Oxygen (DO) across the treatments were generally low and fell below 5 mg/L suitable for fish proper development and maturation (Okey-Wokeh et al., 2020) [18]. This low concentration of Dissolved Oxygen (DO) may have caused the increase in FCR value and mortality recorded during the experimental trial (Yakubu et al., 2015) [7]. Low Dissolved Oxygen generally recorded, could be because the experimental trial was carried out in a closed environment which was not open for atmospheric air.
5. Conclusion
The study of growth performance of African catfish (Clarias gariepinus) fed different standard feeds revealed that fish fed with Coppens performed better in growth response than Multifeed and Vital feeds. This performance in growth was because of crude protein content as shown in the proximate analysis result. But due to the cost of importation of Coppens and Multifeed into the country as imported feeds, vital feed which is a locally made commercial feed could be used because of its availability, low cost and nutritional composition that also met the nutritional needs of Clarias gariepinus.
This article was originally published in International Journal of Fisheries and Aquatic Studies 2020; 8(5): 394-397.
