Assessment of the hormonal and antioxidant status of the sheep of different age groups

The purpose of the research was to study some indicators of antioxidant and hormonal status in the body of ewes and young sheep of the Romanov breed, as well as to identify correlations between the studied indicators. The experiment was carried out in the physiological yard of the L.K. Ernst Federal Research Center for Animal Husbandry in spring of 2022 with stall housing, on 2 groups of ewes (30 days, n = 15 and 90 days after lambing, n = 14) and 3 groups of young Romanov breed (aged 1, n = 15, 3, n = 14 and 4 months, n = 13). Indicators of antioxidant and hormonal status were determined in the blood. Mathematical and statistical processing of the results was carried out using methods of descriptive statistics, one-way analysis of variance, and correlation analysis. The high level of total antioxidant status in the blood of ewes 3 months after lambing (2.38 mmol/l) indicates successful adaptation to oxidative stress and LPO accumulation through the use of enzymatic and non-enzymatic antioxidants. In the blood of lambs upon weaning, the maximum accumulation of TBA-AP is observed compared to animals at one month of age (3.49 versus 3.21 μM/l at p≤0.05), which is compensated by the body by increasing the level of ceruloplasmin and catalase number. At an older age, the body shows adequate adaptation to post-weaning stress, which is manifested in a decrease in the level of TBA-AP by 24.93 % (p≤0.05), an increase in the concentration of ceruloplasmin, a decrease in peroxidase activity (by 28.47 % at p≤0.001 and 8.13 %, compared with the age of 1 and 3 months, respectively), increasing the TBA-AP/CP ratio. The acquired knowledge about age-related and physiological changes in LPO, AOD and hormonal status will be useful in assessing the health status and will help to provide timely preventive measures that increase the adaptive capabilities of the sheep’s body and the fullest realization of the genetic potential of productivity.