Volume 2 Issue 3
Authors: S. E. Abdallah; W. M. Elmessery
Abstract: Feeding management provides the producer with a possibility to overcome limited feeding that may exhibit aggressive behavior during feeding due to limited feed availability resulting in carps that do not reach maximal growth. Overfeeding results in feed waste, poor water quality, lower economic profit and additional environmental pollution. An automatic feeder was constructed and evaluated to provide predetermined amounts of food to four fish tanks (9.5m diameter) had 7000 Carps. Growth methodology optimized carp production in the tanks which are grouped in four, three tanks worked as rearing tanks and the fourth as nursing tank. These big tanks required a better of food distribution so three points of the tank were selected as feeding spots: two aside the edge of tank wall and another close to the center. Each point or wireless controlled gate provided the necessary food, giving more chance to the fishes to obtain their provisions without competition. The system uses a hopper which is capable of feeding the four tanks during a week, and the precision of the hopper was relied on a weighting mechanism. Two ways were used to control food provisions in this study. An opened control system based on the ATM89c51 microcontroller controlled the exact dosing based on the tank rquirements according to the carp cycle and the other closed loop control system was determined by the conditions of water temperature, fish age, body weight and the amount of oxygen consumed. The amount of oxygen consumed by carps was the best parameter knowing fish metabolism and growth that the feeder can rely on its controlling meals provisions. The results showed minimal differences in growth (P<0.05) between treatments, a food saving of 25.337% (i.e. 3495.5 kg), and lower water pollution (reduced water dissolved solids and ammonium components) compared with the first automatic feeder.
Keywords: Carp Feeder; Weighting Mechanism; Control Systems; Oxygen Consumption; Intensive Aquaculture Systems
Authors: A. Isa; M. A. Barka; M. S. Abubakar
Abstract: A survey to assess the turning patterns utilization among tractor operators was conducted in five (5) study locations namely, Madagali, Maiha, Michika, Mubi-North and Mubi-South local government areas, all within Mubi Region between May and September, 2008. Other related parameters measured were; gross arable land, tractor distribution and functionality status in the region. Two hundred and fifty (250) tractor operators and mates’ perceptions were purposively sampled using administered questionnaires primarily designed to generate data on the subject. The data generated during study were statistically analyzed and compared using simple percentage and Likert scaling test. The result indicated that a region has only one hundred and thirty (130) functional tractors and gross arable land of 697052.7 hectares. The tractorization intensity of the region was 9.7W/ha, with one tractor of 70Hp chasing 5502.88ha of land as against FAO recommended ratio of one tractor of 70Hp to 28ha of land. The result further indicated that the turning patterns that were always employed by the operators in the region are: 1800 loop less semi-circular and 1800 open loop pear-shape turns. It was recommended that the stake holders should unify efforts in providing sufficient tractors and foster farm power skill acquisition among the illiterate tractor operators in the region.
Keywords: Field Efficiency; Gross Arable Land; Tractorization Intensity; Tractor Operators; Turning Patterns