ABSTRACT
Experiments were conducted at the Fish Culture Research Institute, in Szarvas, Hungary, to estimate the “effective manure production”, i.e., the amount of manure released into pond water, by ducks on fishponds. The experiments were carried out between April 15 and September 30, 1992 in four repetitions. They were conducted at the Institute’s central duck farm, on a 0.1 ha rectangular fishpond, using “Szarvas high bred” ducks under natural lighting conditions. Manure production volumes were determined from thirty ducks kept in individual cages, and the chemical composition of duck manure was analyzed. Using water temperatures to estimate the amount of time spent in the water by the ducks, three distinct growing seasons were identified: April to May; June to August; and September to October. The resting time was shorter for ducks stocked to the pond in the summer season, and longer for those stocked spring and autumn.
