According to the quantity of produced fish, carp fish species (Cyprinidae family) are most widely spread in fresh water
aquaculture (more than 70%). Carp breeding is carried out in warm water (carp or flatland) fishponds. Carp is bred alone,
i.e. in monoculture, or together with the accompanying species (white and grey Hypophthalmichthus mol., Ctenopharyngodon
idella, tench etc.) and predators (catfish, perch and pike) in policulture. Depending on the type of feeding, application
of ichthyological and agro-technical measures, we can distinguish three carp breeding systems:
- Extensive
- Semi-intensive (or semi-extensive)
- Intensive.
Extensive system
Extensive system implies carp breeding based on natural feed (zooplankton and bed fauna). The advantage of such a system is
in low production costs. The disadvantage is in small yield per surface unit (300 to 700 kg), which is the reason for
constant reduction of scope of such carp breeding system.
Semi-intensive system
A semi-intensive system is based on provision of the largest portion of the protein component of carp feed at the expense
of natural feed, the growth of which is being stimulated by implementation of agro-technical measures, while the needs of
fish for energy are satisfied mainly with carbon-hydrate based (wheat, corn, barley etc.) supplement feed. The production
that is achieved due to the application of carbon-hydrate based supplement feed ranges from 700 to 1.400 kg/ha. The
advantage of such a system in comparison to extensive system is primarily in better utilisation of the available water
surface. The disadvantage of this system is in the fact that available carp feed (both natural and artificial
carbon-hydrate based supplement feed) lack with proteins during the periods of optimum temperature conditions
(June – first half of October) due to natural depression of natural feed. The best way to overcome this problem is to use
complete feed in carp breeding. Supplementary feeding with complete feed enables doubling of production per hectare of
fishpond surface (from 2 to more than 3 tons per hectare). In addition to the direct effect of use of feed with larger
percentage of proteins the indirect effect is also achieved via nitrogen and phosphorus that are liberated upon digestion
of complete feed and that contribute to growth of natural food in fishponds in periods of natural depression. Another
positive effect is certainly the maintaining of much better quality of water having in mind that the use of complete feed
results with multifold lower conversion rate coefficient in comparison to the use of grain crops in diet, which means that
the quantity of faeces in water is also much lower. The carp of large individual weight and exceptional meat quality
appears as the final product of this type of feeding. Finally, this type of feeding provides for a good profit and stable
production.
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Intensive system
Contrary to a semi-intensive system where carp feeding is, more or less, based on natural food, the intensive system
implies that feeding relies mainly on supplementary – complete feed with higher protein percentage (from 30% to 40% of
proteins). In addition to a request for complete feed, a large hatching density also implies the additional water aeration
in fishponds or provision of water flow through a fishpond. The production in land facilities that is achieved via this
breeding method is from 3 to more than 20 tons per hectare of water surface. The advantage of such production is in the
maximum utilisation of the available fishpond surface and large production per surface unit. The disadvantage is in the
increased possibility of disease transmission and increased water pollution in the fishpond and later of water in the
recipient.
The cage carp breeding system is a special form of intensive production. Such a breeding system provides for small initial
investments in construction of the cage fishpond, small number of employees, large fish production per unit of volume and
profitable production. The disadvantage is in facilitated disease transmission and increased pollution (that can be
prevented with protection system installing) of an aquatic eco-system that the cage breeding system is installed into.