Free choice of food for welfare of a limited population of two year old carp (Cyprinus carpio L.)

Abstract

The article provides data on the use of auto-feeders for the free choice of compound feed of different composition by two-year-old carp. Self-feeding is one of the ways that make it possible for fish to receive the necessary nutrition, depending on their biological rhythms, regardless of the desire of a person. This method takes into account the concept of “appetite”, which has a significant impact on the rate of feed intake, thus providing the basis for the wellbeing of aquatic organisms. At the same time, the behavior of fish changes, which makes it possible to use food resources more advantageously for gaining body weight, which has been repeatedly shown. The production quality of fish depends not only on the method of feeding, but also on the composition of the feed, which meets the needs for nutrients and promotes their intensive growth. Low-calorie food K-111 does not allow two-year-old carp to show their potential, as evidenced by a smaller mass of fish than when using high-calorie Carp 38/12. Two-year-old carp fed a feed complex with different energy content do not grow the same way. From 18.06 to 11.10, the mass of the studied fish increased in variants I, II and III by 4.6; 7.9 and 9.8 times, and the length - by 66.1; 75.5 and 96.8%, respectively. The number of white muscles for 5 months of carp growing when using K-111 compound feeds increases by 11.3%; Carp 38/12 - does not change and K-111 together with 38/12 - by 17.6% (P<0.05). By loading auto feeders with only one type of feed, a person deprives the fish of the right to choose, and it must only eat it "without appetite." This, accordingly, affects metabolic processes, and, ultimately, growth in general. This is evidenced by our experimental results. When caught, the average weight of carp with combined feeding was 1220 g, which is 2.1 and 1.2 times higher than in fish from options I and II, respectively. Free choice of food allows you to grow fish with a high yield of muscle mass, due to a higher growth rate. When giving a choice, carp prefers high-calorie food (approximately ¾ of the diet), but at the same time does not neglect low-calorie food in a certain proportion (1/4 of the diet). The use of different quality feeds in one pond allows, in our opinion, to comply to a large extent with the Welfare conditions when raising fish. Thus, the use of automatic feeders with different rations in one pond enables the fish to fulfill their needs for a particular food. Such studies make it possible to identify favorable feeding conditions for the cultivation of various types of fish.