ISI STRESİ ALTINDAKİ SAANEN KEÇİLERİNDE VİTAMİN E VE SELENYUM KULLANIMININ ANTİOKSİDAN PARAMETRELER ÜZERİNE ETKİLERİ

Abstract

Turgut S. Aydın Adnan Menderes University, Health Sciences Institute, Veterinary İnternal Medicine, Doctorate Thesis, Aydın, 2025. Objective: The study was conducted to evaluate the effects of Vitamin E and Selenium applied monthly throughout the year on antioxidant parameters in Saanen goats and the relationship of this effect with heat stress. Material and Methods: According to the results of physical examination and laboratory tests (complete blood count and serum biochemical findings), 14 healthy female Saanen goats aged 12 months and above were selected for use in the study. These selected goats were randomly distributed to the groups and divided into two groups as Group 1 (n=7) and Group 2 (n=7). The animal groups were taken to separate paddocks and were cared for and managed with total mixed ration and adlibitum water without any changes in their feeding regimes throughout the study. Vitamin E-Selenium (Se) (Yeldif, Ceva, Turkey) was applied to the goats in Group 1, which was created for the purpose of the experiment, at a dose of 2 ml yeldif/50 kg live weight, and 2 ml 0.9% NaCl was applied to the goats in Group 2 as a single dose subcutaneously in the first week of each month. To determine the total oxidant level (TOS), total antioxidant level (TAS) and thiol disulfide (total thiol (TTL), native thiol (NTL), disulfide (DS) levels, 4 ml blood samples were taken from the jugular vein into lithium heparin tubes. All sampling and applications were monitored once a month for 12 months (seasonally). Results: In this study, it was investigated whether the application of Vitamin E and Selenium had a significant effect on the changes between environmental temperature-humidity index (SNI) and antioxidant parameters (TTL, NTL, DS, TAS, TOS) in Saanen breed goats followed for 12 months. In this study, it was determined that heat stress occurred in the summer season when SNI values increased. TTL levels, which fluctuated over time, were found to be higher in the study group, especially in March and October, compared to the control group. NTL levels, which showed a significant increase especially in the control group in February, did not show a significant change in the other months. The antioxidant effect of Vitamin E and Selenium application was revealed by the significant decrease in DS level at the end of the year. Although TAS and TOS levels showed fluctuations in both groups during the year, no significant change was formed and they showed a similar course. In the regression analysis performed between SNI and antioxidant parameters, a positive and significant relationship (p = 0.048) was detected only between TTL and SNI. Conclusion: In this study, although there were changes between the study and control groups in all oxidative stress parameters, it was determined that these changes were not significant. Keywords: Vitamin E, Selenium, heat stress, TAS, goat.