Loading of integrated fishponds with organic matter under approaches of mule ducks (Anas platyrhynchos x Cairina moschata) feeding
2009
Nikolova, L., Institute of Fisheries and Aquaculture, Plovdiv (Bulgaria)
The effect of the feeding regime of mule ducks on loading of fishponds with organic matter in integrated fish-cum-duck technology was studied at the Institute ofFisheries and Aquaculture - Plovdiv. The stocking density ofthe ducklings was 340 pcs.ha-1. The coefficient ofloading М was used for establishing the pond loading: M = N- 9P6W r, where N is the mean number of ducks in the rotation; t - rotation length in days; W - average live weight of the ducks for the growing period, kg; 96 g - the amount of the manure released for a day by one duck per kg of live weight; P - pond surface area, ha; r - relative stay of the ducks in water out of the active time of days.Two regimes of feeding the mule ducks were studied. It was established that when fed on abalanced mixture, the mule ducks spent the bigger part ofthe day on landas a result of which during the period ofthe study 40 days the manure inserted in the pond amounted to 74.7 kg.ha. Substituting 50 % of the mixture with wheat, maize or sunflower groats - preserving the energy and protein levels, led to prolonging he average length ofstay ofthe mule ducks in the pond almost 8 times. Dueto the more significant differences in the time spent in the pond during the last ten-day periods, the manure released into water increased by more than Wtimes, although the live weightin all the periods was lower compared to he first variant.
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