DEVELOPMENT OF AN INTEGRATED POULTRY/FISH HUSBANDRY AND MODELLING OF RELEVANT ENVIRONMENTAL PARAMETERS

Abstract

The need to find alternative but productive means of managing animal waste in modern agriculture cannot be over-emphasised. One important means of managing these wastes is through conversion to important use either as animal feeds or as manures. Fish farming can be combined with poultry, animal husbandry and irrigation practices, which can lead to higher production and net profits. This practice is called integrated fish farming or integrated aquaculture. The integration of animal husbandry, especially poultry, with fish farming in a small scale results in the production of organic manure for the fertilization of the fish pond to increase the production of the natural food organism (planktonic algae) for fish to eat. In some cases, the poultry wastes are used as direct food by some fishes without supplementary feeding; such species include the Nile tilapia and African catfish Therefore, the study was aimed the development of an integrated poultry/fish housing unit that will promote productive poultry and fish farming in the study area and as well develop a model using environmental parameters that would affect poultry birds in a vertical integrated poultry/fish unit. An integrated poultry/fish housing unit was designed and constructed such that poultry droppings were made to drop into the tanks directly and used as fertilizer for rearing the African catfish, Clarias gariepinus. The set-up was made of four concrete tanks (1m x 1m x 1m) on which three wooden battery cages were mounted except the fourth pond which served as the control. The ponds were stocked with twenty (20) juvenile Clarias garipinus of about 20 g each. A single factor experiment was adopted with randomized complete block design (RCBD). There were four treatments and two replicates, Fish in tanks 1, 2 and 3 were fed with droppings from one broiler, two broilers and three broilers, respectively. While fish in tank 4 were fed with a commercial fish feed to serve as control. A total of six birds (4 weeks old) and 80 juvenile C. gariepinus were used. This experiment lasted 168 days. During this period, environmental parameters were monitored and the effects of poultry droppings on the growth of the fish were determined. The micro-climate studies were carried out on an integrated poultry/fish unit and the response of the poultry birds to the environmental factors was carefully analysed. A model of the influence of environmental factors on the development of the birds was developed. The developed model was calibrated and validated using regression model diagnostic tools like leverages, cooks distance and probability plots. The experiment was repeated for three consecutive years, 2004 (April September), 2005 (February- August) and 2006 (March- September). The highest Weight gain (WG) value was obtained in tank 4 and the least in tank 3. The average daily growth rate (ADG) and specific growth rate (SGR) data followed the same trend as WG. Weight gain, ADG and SGR decreased linearly as the dropping levels increased. The fish growth indices data obtained were compared with the control and they were all significant (p = 0.05). Weight gain in fish in tank 1 increased at a rate of 10.85 g/week up to the 15th week after stocking. Thereafter, weight gain increased constantly at a rate of 86.8g/week up to the 20th week after stocking and thereafter decreased to a rate of 136.56 g/week up to harvest period. In tank 2, the weight of the fish increased at 7.47 g/week up to 8th week. Thereafter, the weight gain increased at a rate of 24.88 g/week to 16th week and then decreased to a rate of 42.75 g/week up to harvest period. The same trend was observed in tank 3 but the weight gain increased at a rate of 8.06 g/week up to the 4th week and then at a constant rate of 10.89 g/week to the 16th week. Thereafter, there was decrease in the rate of weight gain to a rate of32.36 g/week up to harvest period. Tank 4, which served as the control, showed a different trend in the growth of the fish, where there was a weight gain at an increasing rate of 12.90 g up to the is" week after stocking. Thereafter the rate of weight gain decreased to a rate of 147.22 g/week up to harvest period. A log-log plot of the weight of birds and time is a straight-line graph which suggests the growth of birds as a power of time similarly observed for other studies. The study showed the possibility of effective poultry waste management technique which ensured that nothing is wasted and waste handling problem is greatly minimised. Pollution of water in tanks resulting from the poultry droppings adversely affected the water quality ad growth of the fish in this study. Increase in the volume of droppings led to increase in the Bio-Chemical oxygen demand and Chemical Oxygen demand of the tank water which consequently led to a decrease in the dissolved oxygen concentration. Water turbidity also increased with increased volume of droppings. Other water quality parameters such as conductivity, chloride and pH values were within the acceptable requirement values for fish culture. The developed model is a good engineering solution for prediction of poultry birds' development based on environmental influence in a humid tropical environment and findings from this study will be useful for adoption and careful planning of an integrated poultry/fish husbandry for optimum productivity.