Intensity of growth and development of rainbow trout using feeds Aller Aqua and Aquafeed Fischfutter
Authors: Pivtorak J. I. , Bobel I. Y. 
Published: November 2017

Due to the rapid development of feed since the early 1990's, efficiency has increased dramatically. The effectiveness is achieved by increasing energy levels, reducing the level of carbohydrates and balancing various nutrients that meet the needs of fish. Improvement of efficiency should be taken into account when determining the amount of ration feeding. The economic efficiency of growing fish depends largely on proper feeding. The feed should be dosed depending on its formulation and size, the physiological state of the fish, the temperature of water and the content of oxygen in it. Salmon fish are demanding oxygen treatment. The content of oxygen in water should be at least 7 mg/l. At a lower oxygen level, the growth of fish is suppressed, and the effectiveness of food is reduced. The optimum temperature of water for growing salmon fish is 14–18 °С. Excessive feeding leads to unproductive feed costs and water pollution, insufficient  feeding leads to incomplete realization of potential opportunities for the rate of growth of fish. The quantity of the daily ration is established taking into account the temperature of water and the mass of fish. Depending on their state, activity and conditions of maintenance, it can fluctuate within ± 20% of the norm. In addition, high fertility densities, unsanitary conditions, illness, low water exchange rates, low oxygen content in water affect the efficiency of feeding in trout farms. Due to the fact that the cost of forage for trout is up to 60% of all costs for its cultivation, the problem of it rational use and saving is at the forefront. When feeding trout it is necessary to take into account that the size of granules for young fish in the length of 4–20 cm should be from 2.2 to 2.6% of the body length (according to Smith), which corresponds to the size of the mouth and the distance between the gill stamens in rainbow trout. Fish is best fed often in small portions. The smaller the fish, the more often feeding. Going on a feed of another size or type should be gradually over 3–5 days. If necessary, it is necessary to use special therapeutic granulated food or a mixture of therapeutic ingredients to add to the wet granules. It is necessary to create optimal conditions for growing and to carry out constant monitoring of water temperature and its fluctuations, oxygen content in water, pH, atmospheric pressure, etc. It is necessary to follow the rules of storage of forages, taking into account that the quality of feed after being stored for more than 3 months is deteriorating. This happens. It may be caused by poor water quality or disease. In order for the fish to get used to a particular feeding regime, it is recommended to do feed it at the same time. Today, the diversity of feeds allows you to get a better feed rate, fast growth and a minimal impact on the environment under different conditions, since the need of  fish in nutrients is fully covered by feeds (energy, protein, minerals and vitamins). The use of Aller Aqua feed guarantees receiving of a strong, healthy fish, thus providing good economic performance to farms. The basis of the research is the analysis of the nutritional value of the feeds of the company Aquafeed Fishsfutter of the German producer and Aller Aqua of the Danish company in the production conditions on the farm of the Western Fish Company PP of Peremyshlyany district, Lviv region. Also we should study fodder, their composition and carry out an objective assessment. It is known that fodder of foreign producers are characterized by higher energy value due to increased fat content, which is achieved by application of the appropriate technology and equipment for vacuum desiccation. For example, Aller Aqua's salmon-based compound feed for protein levels 40–46% contains 15 to 32% lipids and 23–24 MJ/kg of gross energy. Due to the high energy value, these feeds allow to provide the growth of fish at low feed costs. The aim of the work was to analyze the impact of different producers of feed fodder for commodity groups of trout on their growth and the development and receipt of quality commodity products in short terms.