Background: Thiol/disulphide homeostasis (TDH) has a critical role in many cellular activities such as antioxidant protection. Alterations of oxidative stress in the transition period play an important role in development of some diseases and disorders in dairy cows.Objectives: The purpose of this study is to assess the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), total thiol, native thiol, disulphide and lipid profile in Simmental and Montofon dairy cows (aged 2–3) before and after calving.Methods: Blood samples were collected 233–280 days of pregnancy and the 30 days of post‐partum. Serum total thiol, native thiol and disulphide levels were determined as well as TAS, TOS and paraoxonase‐1 (PON‐1) levels were measured using colorimetric assays. Triglycerides (TG), total cholesterol, HDL cholesterol and LDL cholesterol levels were measured with an automatic analyser.Results: Total thiol (p = 0.038) and disulphide (p = 0.015) levels were higher after calving compare to pregnancy in Montofon. TAS was found lower (p < 0.001), and OSI was higher in both breeds (Montofon p = 0.012, Simmental p = 0.028) after calving than in pregnancy. When compared between pregnancy and after calving levels in the same breed, HDL was found to be higher after calving (p < 0.001) and TG was lower after calving (p = 0.020) in Montofon. PON (p = 0.090), HDL (p < 0.001) and cholesterol levels were found higher (p < 0.001) and TG level was lower (p < 0.001) after calving in Simmental.Conclusions: According to our results, we observed different responses between two breeds before and after calving. There are few studies about TDH in animal research, and this is the first study in the literature that evaluates the TDH along with oxidative stress and lipid profiles in dairy cows in the periparturient and post‐partum period.

This study was conducted to determine the levels of serum total cholesterol in Hair goats in different gender and age ranges. For this purpose, the blood samples from 120 Hair goats, young (£ 6 months) and adult (2-4 years), which were found to be clinically healthy, were taken from the vena jugularis. Triglyceride, total cholesterol, HDL and LDL cholesterol levels were measured in sera samples. The mean values in adult female goats, young female goats, adult male goats and young male goats were found. Triglyceride levels were found to be higher in male goats than in females. It was observed that the HDL values obtained from male kids were lower than the other ones. The LDL results obtained from the goats were close to each other and statistically insignificant. Thus, in this study, the data obtained is considered to contribute to the formation of reference values in the Hair goats.n

This study aimed to evaluate the effects of body condition scores (BCSs) on oxidative stress and thiol/disulphide homeostasis (TDH) in Holstein pregnant heifers during the transition period. A total of 36 healthy primiparous heifers in the 7th month of pregnancy, all approaching their first calving, were included in the study. The animals were allocated into three equal groups based on their BCS. The BCS measurements were performed 21 days pre‐calving and on the 21st day post‐calving. Pre‐calving and post‐calving serum levels of total thiol (TTL), native thiol (NTL) and disulphide (DSF) were quantified using standard techniques. The study revealed significant differences in BCS, TTL and DSF values among groups both pre‐ and post‐calving ( p < 0.05), whereas the changes in NTL values were statistically insignificant ( p  > 0.05). Overall, a decrease in BCS and NTL levels was observed, accompanied by an increase in TTL and DSF levels. Correlation analysis within groups indicated low‐level relationships between changes in BCS and TTL, NTL and DSF levels. Consequently, regression analysis did not yield any statistically significant predictive models. The results showed a differential response between the loss of BCS and the oxidative stress during the periparturient period. The increased DSF levels observed during late pregnancy and early lactation indicate a deficiency in antioxidant substances in the animals. Therefore, supplementing the ration with a premix containing antioxidant substances during the transition period may provide significant benefits in terms of maintaining the BCS balance, animal welfare and herd health.

Nigella sativa (NS) has a protective effect on cellular damage caused by oxidative stress. Selenium has an antioxidative effect. Toxocara canis is one of the nematodes causing visceral larva migrans. Men infected with this parasite ingesting an embryonic egg. It is more common in children between 1-4 years than adults. From the ingested embryonic egg, the larvae released in the small intestine and they migrate to so many organs such as liver, spleen, kidney, lung, brain, retina of the eye, pancreas and causing lesions. In particular, it is known to cause intense damage to kidney tissue. In this study mice with Toxocara canis infection were administered Nigella sativa in prophylactic and treatment doses (100 and 200 mg/kg body weight) and selenium levels were determined in their kidney tissues. In the healthy control group, kidney selenium levels were 980,46±236,68 ng/g and in mice infected with Toxocara canis 1240,15±315,77 ng/g. Kidney tissue Se levels of mice given NS in two different doses for treatment (Treated N100, Treated N200) and prophylaxis (Prophylactic N100 and ProphylacticN200) respectively are 1297,95±354,37; 1361,29±410,46 ng/g; 1148,55±240,28 ng/g and 1465,81±450,25 ng/g. Kidney tissue selenium levels were high in both treatment and prophylaxis dose NS given mice. In conclusion, Nigella sativa can cause increases in kidney tissue selenium levels depends on given doses.

In this study, it is aimed to determine the effects of adding humic acid to ration of Anatolian Merino lambs on the fattening performance and some oxidative stress level by using thiol / disulfide balance measurement method. In the study, singleton 32 male Anatolian Merino lambs with an average age of 2.5 months were used. The experiment was carried out by forming a control group without additives and four trial groups, three of which were added with humic acid (2, 4, 6 g/kg), with 8 replications in each group for a total of 70 days. The lambs housed in the group partitions were fed with 350g/day/head of alfalfa grass as roughage and lamb grower feed ad-libitum containing 2750 kcal/kg DM ME, 16% HP until the end of the trial. At the end of the research; intra-group native thiol (NTL, μmol/L) values increased on the 30 th day (P<0.05) in all groups except the control group, while total antioxidant status (TAS, mmol/L), total thiol (TTL, µmol/L) and disulfide values increased on the 60 th day in all groups including the control group ( P≤0.001) was observed. In terms of lambs' feed consumption, live weights, body weight gains, feed conversion ratios, TAS, total oxidant status (TOS, μmol/L), OSI, TTL, NTL and disulfide was found that there was no significant difference between groups (P˃0.05). It was concluded that the humic acid additive was not effective on the fattening performance, but 4 or 6 g/kg could be added to the lamb rations due to the increase in thiol groups, which have an important role in the antioxidant defense system.