Development and Performance Evaluation of an Automatic Fish Feeder

Aquaculture (fish cultivation), a rapidlygrowing entrepreneurial activity, contributes to food security and poverty alleviation in many developing nations. Feeding is one of the most important aspects of fish growth and production. A major challenge facing aquaculture development is the management of feeding systems. Feed adjustment to meet fish requirement is very important for income/benefit maximization. Feeding frequency is thus an essential consideration. Aderolu et al., [1] studied the effect of feeding frequency on growth performance, feed utilization and economic viability of African catfish (Clarias gariepinus).


Introduction
Aquaculture (fish cultivation), a rapidly-growing entrepreneurial activity, contributes to food security and poverty alleviation in many developing nations. Feeding is one of the most important aspects of fish growth and production. A major challenge facing aquaculture development is the management of feeding systems. Feed adjustment to meet fish requirement is very important for income/benefit maximization. Feeding frequency is thus an essential consideration. Aderolu et al., [1] studied the effect of feeding frequency on growth performance, feed utilization and economic viability of African catfish (Clarias gariepinus).
The efficiency and profitability of aquacultural practice could be enhanced with improved technology. This has necessitated the design, development and construction of automatic feeding devices to meet feeding needs and to reduce labor requirements, thereby reducing the cost of fish production.
Mohapatra et al., [2] developed and tested a demand fish feeder, fabricated with Fibre Reinforced Plastic (FRP) material. The feeder was specifically for carp, and was tested in outdoor culture systems. Demand feeders, controlled by the fish needs, could be bait-rod (pendulum)type or submerged plate-type [3]. Tadayoshi [4] developed an automatic fish feeder which had the capability of sensing uneaten feed. Noor et al., [5] designed an automatic fish feeder using PIC microcontroller. The basic components of the feeder are pellet storage, former, stand, DC motor and microcontroller.
While several automatic fish feeders are available in developed nations, they are scarce in Nigeria and other developing countries (e.g. Anyadike et al., [6]), mainly attributable to the cost of importation. In their design, Anyadike et al., [6] utilized a plastic hopper, with a galvanized-metal discharge chute and a valve attached. The device is capable of discharging 240 g of pelleted feed in 120 seconds. The objective of this work was to develop and evaluate the performance of an automatic fish feeder-to enhance aquacultural practice.

Design considerations
Some properties of the feed pellet considered were: angle of repose, specific gravity and bulk density. Also, parameters considered were:

Design of control box (Timer)
The 555 timer IC can be configured in three different modes: astable, monostable and bistable. The astable and monostable were adopted for this project. These devices are precision timing circuits capable of producing accurate time delays or oscillation. In the timedelay or monostable mode of operation, the time interval is controlled by a single external resistor and capacitor network. In the astable mode, the 555 timer acts as a "one-shot" pulse generator. The time of operation was calculated to be 3 sec, and the range of the operation was assumed to be 1 to 10 sec. The variable resistor that can delay for this period was calculated from the equation. Figures 1 and 2 shows the general features of the automatic fish feeder. The component parts of the machine (device) include: the hopper, top cover (LID), the base (comprising the motor and feed platform) and the electrical control box. The hopper is made of stainless steel (1mm thickness) and it is of composite shape (cylindrical and fulcrum). The top cover is made of the same material as the hopper and it protects the feed from rain and contaminants. The base consists of 6V, 3W bi-directional motor and feed platform attached to it. The feed platform opens and closes the discharge outlet as the motor rotates. The electrical control box controls and regulates the feeding operation and the frequency.

Operation of the machine
The hopper contains the feed which comes out through the discharge outlet. When the machine is switched on and reset, the feed platform moves in bi-directional (to and fro) motion, during which there is opening and closing of the discharge outlet for pre-determined period. The desired amount of the feed would be dispensed into the pond and this completes an operation. After the operation is completed, the machine will automatically stop for preset hours (1, 2, 3…………. hrs) based on the number of operations needed per day. When the hours are completed, the machine will start again and dispense the same amount of feed as in the previous operation, and the operation continues.
The machine is powered by electricity and it has a back-up (6V battery) which can last for at least 3 days (72 hrs) when fully charged. The device can be used for both local and imported dry pellet of size 0.5 mm-9 mm. The cost estimate for the production of the machine was N17,000 (approx. US $106). The construction materials and the Bill of Engineering Measurement and Evaluation (BEME) are shown in Tables 1 and 2, respectively.

Performance evaluation
The performance evaluation of the device was conducted using a recirculatory aquaculture system (RAS) located behind the Department of Agricultural and Biosystems Engineering, University of Ilorin; Ilorin, Nigeria.
Ilorin (longitude 4°35'E, latitude 8° 30'N), the capital of Kwara State of Nigeria, has two main seasons: wet (March-October) and dry (November-February). The experiments were conducted from April to June, 2013, involving two culture tanks, each of 0.75 m 3 volume, with 10 kg-33 juvenile catfish (Clarias gariepinus) placed in each tank with one feeding automatically and the other, manually.
"Durante" fish feed, weighing balance and meter rule were also used in the investigation. The feeder was placed over a stand fixed at the corner of the culture tank. Growth rate of fish was estimated by sampling 10 fishes from the rearing tank every week (7 days interval). The feed conversion ratio (FCR) and the feeding efficiency (FE) were used for the performance evaluation:  Tables 3 and 4 show the catfish growth rate for automatic and manual feeding, respectively.

Results and Discussion
For the automatic feeding (Table 3);   5. Base PVC, motor and wire PVC used to cover the motor, also as feed platform. The wire connects the base to the control box. The base was suspended to the feed hopper using copper wire.
PVC used for casing. The components were laid on the veroboard.  The total average of feed consumed per fish during the period of the experiment = 428.00 g The total average gain in weight per fish during the period of the experiment = 89.50 g A t-test was also used in analyzing the data. Table 5 shows the result of the statistical analysis, at 5% significance level.

Conclusion
An automatic fish feeder was designed, constructed and evaluated. Its main components are: hopper, bi-directional motor, feed platform and electrical control box. The device was incorporated into a recirculatory aquaculture system (RAS) and the evaluation was based on feed conversion ratio (FCR) and feeding efficiency (FE) using juvenile catfish (Clarias gariepinus). The feeding efficiency was higher in the automatic feeding (20.9%) than in manual (18.6%). Use of the automatic feeder will improve aquacultural practice. The total average of feed consumed per fish during the period of the experiment=421.50 g The total average gain in weight per fish during the period of the experiment=78.50 g Table 4: Growth rate of catfish for manual feeding.

Feeding Method
Mean gain in weight per fish(g) Standard deviation (g) t-test value The mean gain in weight per fish in automatic feeding was higher than in manual.