Mathematical Equations for Reducing Water Pollution Problems among Poultry Production Clusters in Nong Khai Province, Thailand

Poultry production clusters (PPC) in Nong Khai raise layer chickens in the poultry houses constructed over fish ponds. Layer farmers use chicken manure to feed their fish. However, unbalance between chicken raising and the size of fish pond or number of fish results in low water quality, which affects fish production and the community’s public water resource. In this field study, data was collected from layer farms in three poultry production clusters in Nong Khai province in the northeast of Thailand (a total of 90 farms) between April and August 2013. Data collected consisted of observations of dissolved oxygen (DO) values of water in the fish ponds, the number of egg-laying chickens raised above the fish ponds, the number of fish and size of the fish ponds. When all of these four observations were analyzed, mathematical equations for calculating the number of chickens raised, the number of fish per one rai (1600 m2), and the size of pond suitable for the number of chickens and fish were obtained as follows: 1) number of fish/rai = 5796 + 1097(size of pond) (R2 = 0.71), 2) number of chicken/rai = 513 + 223(size of pond) (R2 = 0.48) and 3) size of pond =-0.328474 + 0.000262(Fish) + 0.00117(Chicken) (R2 = 0.40). When pond = desired pond size, fish = number of fish to be raised and chicken = number of chickens to be raised.