Efficiency of using experimental feeds with different levels of nutritional value in carp feeding

This article presents a study of carp farming technology using feeds with different nutritional levels. In Ukrainian aquaculture, the most significant results in fish farming are associated with the development of feeding technology. The experimental part of the research was carried out at the PJSC “Lviv Regional Production Fish Plant” production facilities during the 2023 growing season. The object of study was the Ukrainian scaly carp (Cyprinus carpio). Two feeding ponds (№ 1, № 2) were used for the experiment, where carp were reared in polyculture with variegated (white) silver carp. Fish in control pond №1 were fed fish feed of recipe 110–1, and fish in experimental pond № 2 were fed experimental feed. At the same time, a hydrochemical analysis was conducted in the ponds, and the amount and biomass of the natural feed base (phyto-, zooplankton, and zoobenthos) was determined. As for the main hydrochemical parameters, oxygen content, oxidizability, and pH did not exceed the normative values. According to the research results, the indicators of phytoplankton development in the experimental ponds varied from 0.2 to 510.8 million cells/dm3, biomass – 0.08–42.5 mg/dm3. Indicators of zooplankton development in the experimental ponds varied within the following range: by number – 85.5–580.5 thousand specimens/m3, by biomass – 3.0–14.5 g/m3. The average seasonal biomass of zooplankton for the growing season was 8.6 g/m3, which is within the normal range for the ponds of the studied region. The average seasonal indicators of zoobenthos abundance in the experimental ponds were 245.1–325.8 specimens/m2, and biomass was 1.7–2.2 g/m2. For feeding the carp of the control group, the farm used fish feed from recipe 110–1. The experimental feed for carp was a floating feed with a high protein content, which is ideal for carp breeding and allows significant increases in their live weight. To experiment, 2 feeding ponds, № 1 and № 2, were used, with a stocking density of 3.5 thousand fish per hectare. The carp yield in polyculture was 82.0–84.0 %, with an average weight of 520 and 545 grams, respectively. The fish productivity of carp in pond № 1 was 1492.4 kg/ha with a feed consumption of 4.1 units. In pond № 2 – 1602.3 with a feed consumption of 3.6 units. Studies conducted in experimental ponds have shown that using carp planting material with an average weight of 35 g allows for a two-year growing cycle in the conditions of the second zone of fish farming to obtain commercial carp with an average weight of 530 g without reducing fish production. At the same time, a more significant weight of carp was obtained in pond № 2, where the fish were fed with experimental feed.