Abstract
In the course of optimizing the technology of breeding 400 rainbow trout ( Oncorhynchus mykiss ) specimens in 4 cages (100 specimens in each cage) at the pilot fish pond in 2016 there was evaluated the impact of abiotic and biotic factors of the environment on the growth and development of trout and the dynamics of the temperature and oxygen regimes. The gas regime, physico-chemical properties, the content of the main ions and water biogens from the area of the fishpond were investigated. The research results showed that structure of the cage line is compatible enough compared to those available in the market. However, it is necessary to increase the size of cages to 5-6 m in depth and to use lifting mechanisms in summer to raise water from the depths, because water at 19-20ºC can provoke a great withdrawal of trout. During 30 days of the experiment there was investigated the efficiency of using 4 types of productional feed (in 4 different cages): pilot productional trout feed made by "KazNIIPPP", LLP, and three control variants - "Aller Aqua" (Danmark) feed and two productional feed types made by Kazakh manufacturers. Best results gave the trout species fed with "Aller Aqua" feed. Values of absolute, average daily and relative trout growth fed with pilot feed of "KazNIIPPP", LLP were higher than if fed with feeds of other Kazakh manufacturers to 23.3 and 26.7 g; 0.81 and 0.89 g; 13.0 and 11.8%; feeding ratio - to 0.7 and 0.65 units. The difference between feeding ratios of "KazNIIPPP", LLP feed and "Aller Aqua" feed was minimum - 0.6 units. Subject to the fact that "KazNIIPPP", LLP feed is not much inferior to the import feed in quality and profitability, its manufacturing technology is preferable to use in commercial trout breeding