The restoration of freshwater aquatic life and the cultivation of highly productive sires is a key stage in the process of restoring a new generation of fish, thus, the task of increasing fertility is always relevant for the fishing industry of Ukraine. The purpose of the study is to conduct an in-depth analysis of the physiological characteristics of ejaculates of respiratory and reproductive capacity, to explore the activity of enzymes of the respiratory chain of mitochondria, to determine the percentage of sperm survival when using pre-cleaned oats, as the main component in the diet of carp during the pre-spawning period In the study, males of the Nyvka interbreed type of Ukrainian scaly carp breed were used, which were kept during the pre-spawning period in pond conditions of the State Enterprise “State Farm “Nyvka” IRG NAAS. Individuals were divided into 3 groups. The first group (Experiment I) was fed 100% hulled oats, the second (Experiment II) – 30% and the control group of fish (Control) was fed a grain mixture. The quality of male carp sexual products was assessed by determining the effect of adding hulled oats to their diet during the pre-spawning period. Indicators of sperm motility and fertilizing ability, the content of γ-, β- and α-globulins, albumin, prealbumin and physiological characteristics of ejaculates of respiratory and reducing capacity, the activity of enzymes of the respiratory chain of mitochondria (COX and SDH) were explored. Considering the increase in the productivity of fish sperm, in particular, the increase in the number of sperm with rectilinear motion, the decrease in the number of lifeless sperm and changes in the protein formula of germ cells, it was established that it is advisable to add hulled oats to the main diet in the amount of 30%. According to the results of the conducted research, it was established that the addition of hulled oats to the fodder during the pre-spawning period has a positive effect on the quantitative and qualitative indicators of male carp sexual products, the results of the research can be useful for both students and workers of the fish processing industry of Ukraine