“…It is noteworthy, that technology of using an animal tissues as source of bioactive proteins and peptides is a new trend in veterinary sciences ( Baradaran et al, 2017 ). Biofactors derived from animal tissues, where the main active ingredients are endogenous protein compounds, have been used to stimulate immunity, metabolic processes, regeneration processes and other ( Chen et al, 2019 , Crosby and Kronenberg, 2018 , Novoseletskaya et al, 2015a , Novoseletskaya et al, 2015b , Vasilevskaya and Akhremko, 2019 ). Natural proteins and peptides exhibit higher specificity and effectiveness in comparison to traditional drugs ( Kalkhof et al, 2014 , Yang et al, 2019 ).…”