A pneumatic fish feed distributor was designed and locally fabricated for Egyptian fish farms to ensure all the fish have equal access to the feed and avoid the manual feeding problems. The performance of the designed pneumatic fish feed distributor was evaluated based on fish pellet degradation, uniformity of fish feed distribution pattern and performance of feeding method. The evaluation was calculated at different operation conditions including different blower air speeds from 10 to 20 m/s, forward speed from 2.62 to 6.39 km/h (from 0.73 to 1.78 m/s, respectively) and feed rates from 10 to 25 kg/min.
The obtained results lead to the conclusion that:
Using of pneumatic fish feed distributor gave the best results of feed distribution pattern uniformity, eliminated feed breakage wasted as dust and saved about 35%, in fish feeding cost under the optimum operating conditions of air blower speed of 15 m/s, forward speed ranging from 2.53 to 3.42 km/h and feed rate ranging from 20 to 25 kg/min.
Using mechanical feeding method (pneumatic fish feed distributor) gained 208.18 ± 24.25 g as an average fish mass with coefficient of variation (C.V) about 11.47% and better feed conversion ratio (FCR) of 1.63 comparing with 183.46 ± 42.73g fish mass with C.V about 23.29% and poor FCR of 1.94 gained by using the hand feeding method at the end of production cycle.
Using of pneumatic fish feed distributor is more suitable and acceptable mechanical feeding method to ensure that all the fish have equal access and similar opportunity to the feed which achieving higher uniformity in growth rate and good feed conversion ratio. In addition, it helps avoiding the manual feeding problems of water pollution due to eliminating waste of pellets dissolved in the water and reduces the feeding labor and cost. Consequently, it increases the benefit margins of fish farm production. Therefore, it is recommended to use pneumatic fish feed distributor under the previous optimum operating conditions.