Prodanović Radiša, Nedić Sreten, Vujanac Ivan, Bojkovski Jovan, Nedić Svetlana, Jovanović Ljubomir, Kirovski Danijela, Borozan Sunčica
Department of Ruminants and Swine Diseases, Faculty of Veterinary Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Department of Reproduction, Fertility and Artificial Insemination, Faculty of Veterinary Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Metabolites. 2023 Feb 24;13(3):334. doi: 10.3390/metabo13030334.
Cows in the peripartal period undergo changes in thyroid hormones and are susceptible to lipomobilization and/or oxidative stress. The addition of chestnut tannins as polyphenolic compounds in the diet may improve feed efficiency and prevent oxidative stress-related health disorders in transition cows. However, the relationship between chestnut tannin supplementation and thyroid function, which plays an important role in metabolic regulation, has not been investigated in dairy cows. This study was conducted to investigate the effects of chestnut tannin supplementation during the close-up period on thyroid status and to evaluate the interaction between thyroid hormones and oxidative stress biomarkers in prepartum dairy cows. Forty multiparous Holstein cows were fed either a diet containing chestnut tannins (CNTs, = 20, 1.96 g chestnut tannins/kg feed, dry matter) or a non-supplemented diet (CON, = 20) during the last 25 ± 2 days of gestation. Blood samples were collected on the first day of study (before chestnut tannin supplementation) and d 5 before parturition to measure hormonal and oxidative stress indices. Serum concentrations of T3 ( = 0.04) and T4 ( = 0.05) were higher in CNT cows than in the CON group on day 5 before parturition. Thyroid status of CNT cows was associated with higher serum total antioxidant capacity (T-AOC, < 0.01), activities of superoxide dismutase (SOD, = 0.03) and glutathione peroxidase (GPx, = 0.01), and reduced glutathione concentration (GSH, = 0.05). Serum thiobarbituric acid reactive substances (TBARS) were lower ( = 0.04) which was associated with lower aspartate aminotransferase (AST, = 0.02), and lactate dehydrogenase (LDH, = 0.01) activities in the CNT than in the CON group. Estradiol and progesterone did not differ between CNT and CON cows. Chestnut tannin supplementation improves antioxidant protection, prevents oxidation-reduction processes, reduces the degree of liver cell membrane damage, and protects thyroid tissue from damage, allowing higher T3 and T4 synthesis. Considering the importance of the thyroid hormone status before parturition, mechanisms of thyroid hormone regulation in CNT-supplemented dairy cows require more detailed investigations.
围产期奶牛的甲状腺激素会发生变化，且易发生脂肪动员和/或氧化应激。在日粮中添加作为多酚类化合物的栗木单宁，可能会提高饲料效率，并预防围产期奶牛与氧化应激相关的健康问题。然而，在奶牛中尚未研究栗木单宁添加与在代谢调节中起重要作用的甲状腺功能之间的关系。本研究旨在调查围产前期添加栗木单宁对甲状腺状态的影响，并评估产前奶牛甲状腺激素与氧化应激生物标志物之间的相互作用。40头经产荷斯坦奶牛在妊娠最后25±2天期间，分别饲喂含栗木单宁的日粮（CNT组，n = 20，1.96 g栗木单宁/千克饲料，干物质）或不添加的日粮（CON组，n = 20）。在研究第一天（添加栗木单宁前）和分娩前5天采集血样，以测定激素和氧化应激指标。分娩前5天，CNT组奶牛血清T3（P = 0.04）和T4（P = 0.05）浓度高于CON组。CNT组奶牛的甲状腺状态与较高的血清总抗氧化能力（T-AOC，P < 0.01）、超氧化物歧化酶（SOD，P = 0.03）和谷胱甘肽过氧化物酶（GPx，P = 0.01）活性以及较低的谷胱甘肽浓度（GSH，P = 0.05）有关。血清硫代巴比妥酸反应物质（TBARS）较低（P = 0.04），这与CNT组比CON组较低的天冬氨酸转氨酶（AST，P = 0.02）和乳酸脱氢酶（LDH，P = 0.01）活性有关。CNT组和CON组奶牛的雌二醇和孕酮无差异。添加栗木单宁可改善抗氧化保护，防止氧化还原过程，降低肝细胞膜损伤程度，并保护甲状腺组织免受损伤，从而使T3和T4合成增加。考虑到产前甲状腺激素状态的重要性，添加CNT的奶牛中甲状腺激素调节机制需要更详细的研究。
