Reproductive Process in Bulgarian Trout Farms in Relation to the Prevention of M74 Syndrome

1 Trakia University, Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, BG-6000 Stara Zagora, Bulgaria
2 Trakia University, Department of Biology and Aquaculture, Faculty of Agriculture, BG-6000 Stara Zagora, Bulgaria


Atanasov, V., Y. Staykov, M. Tzanova, E. Valkova, B. Krastev and Zh. Dimitrov, 2017. Reproductive process in Bulgarian trout farms in relation to the prevention of M74 syndrome. Bulg. J. Agric. Sci., 23 (1): 147–153

Currently, the term syndrome M74 combines all reproductive disorders of hydrobionts (including their gametes, embryos and yolk-sac fry) with similar symptoms caused by xenobiotics transposed in aquatic organisms from polluted environment. Because in Bulgaria there are only few publications on the M74 and the syndrome is not known to fi sh farmers in the branch, the aim of the present study was to analyze the reproductive process in Bulgarian trout farms, located in different mountains regions and make recommendations for preventing M74 syndrome. This is why for the fi rst time in the country were developed criteria for assessing the risk of syndrome M74 and questions were formulated in a special „Questionnaire“. The survey data from 14 Bulgarian trout farms were calculated to analyze the reproductive process and investigate the possibility for spreading of the syndrome M74 mainly on farms located in the following mountains: Rila, Rhodope, Stara Planina and Sredna Gora. Additionally were investigated commonly used biological parameters for assessment of the reproductive syndrome M74 – eggs fertilization, hatchability and survival rate of the rainbow trout fry. Better reproductive parameters were registered in 1st rank trout farms (0-5 points) which have no problems with the M74 syndrome. In the rest farms the unsuitable environmental conditions, which lead to occur M74 syndrome can be partly compensated using a sperm activation medium №49397 for artifi cial insemination of trout eggs.

Key words: salmonidae; artifi cial insemination; sperm activation medium; M74 syndrome

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