Functional biologically active feed additive for breeding stock of fish Elena Romanova, Vasily Romanov, Ludmila Shadyeva, Vaselina Lubomirova, Tatyana Shlenkina, Alexander Vasiliev and Elena Turaeva E3S Web Conf., 363 (2022) 03060 Published online: 14 December 2022 DOI: 10.1051/e3sconf/202236303060