Each breed and type of pig is characterized by its unique complex of biological properties. In addition, pigs of different sexes realize their genetic potential to a different extent. Therefore, research aimed at optimizing the feeding rations of different sex-age groups in pigs of meat genotypes, namely the Pietren breed, depending on their sex, is relevant. Objective. To determine the efficiency of assimilation offeed nutrients by pigs of the Pietren breed, depending on their gender. Methods. The research was conducted in the conditions of the physiological yard of the Institute of Pig Breeding and AIP of the NAAS on 12 pigs with an average weight of 65 kg, namely 6 boars and 6 gilts, which were divided into two groups. Selected average samples of feed and excrement were studied in the laboratory offeeding, physiology and animal health of Institute of Pig Breeding and AIP NAAS. The biochemical composition of the blood of experimental young pigs was investigated using commercial kits from the company "Filisit Diagnostics" Ukraine. Results. It was established that the coefficients of digestibility of nutrients offeed for Pietren pigs do not significantly depend on their gender. However, there is a tendency for 3.05 % better digestibility of mineral substances in piglets. Piglets have better digestibility o f fiber and crude protein, respectively, by 19.20 % and 2.65 %. The average daily balance of Nitrogen and Magnesium did not differ significantly. As for the average daily balance of Calcium and Phosphorus, the excretion of these elements with feces and urine in boars was somewhat less, and it was retained in the body, accordingly, slightly more, but due to the rather significant variability of the indicators, no probable difference between the groups was detected. It was found that the content of Calcium, probably by 17.87 % (р<0.05), and Phosphorus by 9.7%, was higher in the blood of guinea pigs. The content of total protein in the blood plasma of wild boars was probably (p<0.05) higher by 12.5 %, creatinine was probably (p<0.05) higher by 10.44 %, the activity of aspartate aminotransferase was probably (p<0.05) higher by 10.34 %. Conclusions. It was established that the coefficients of digestibility of nutrients offeedfor Pietren pigs do not significantly depend on their gender. However, the analysis of hematological indicators of blood can indicate a higher level of metabolism in boars. Keywords: guinea pigs, pigs, Pietren breed, digestibility coefficient, nutrients, sex, feed, hematological indicators.