THE IMPACT OF DIFFERENT DIET AND ENVIRONMENTAL CONDITIONS ON CHEMICAL COMPOSITION OF RAINBOW TROUT (ONCORHYNCHUS MYKISS WALBAUM, 1792) FROM MACEDONIAN AQUACULTURE FACILITIES

摘要

The main purpose of the research was to make an analysis of the influence of ambient conditions and nutrition on the chemical composition of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) from various aquaculture facilities in Macedonia, in different ambient conditions in the aquatic environment, and with the use of pelleted food from different manufacturers. This research produced additional analyzes that determine the physico-chemical properties and also a microbiological analysis of the water in which the rainbow trout grows, the chemical composition of the food used for its feeding, as well as, the energy value of fish meat from these two aquaculture facilities (fishpond A and fishpond B). The results obtained during the examination of the chemical composition of the rainbow trout meat from the fishpond A determined the mean value of 71.700% water, 20.366% proteins, 5.633% fats and 1.21% ash, while the ones from the fishpond B determined the mean value of 74.533% water, 20.600% proteins, 3.366% fats and 1.38% ash. The energy value of the rainbow trout meat from the fishpond A was 568.941kJ/100 g, while the one from the fishpond B was 484.635 kJ/100 g. Overall, by a comparative analysis of the chemical composition of the rainbow trout from both aquaculture facilities, as well as energy value of fish meat, the ambient conditions prevailing in the aquatic environment, and the forage mixtures used for feeding fish, it can be concluded that both aquaculture facilities are producing high nutritional quality fish.