غلظت سرمی لپتین و انسولین و ارتباط آن با پروفایل لیپیدی در گاو‌های هلشتاین قبل و بعد از زایمان

From early to mid-pregnancy in cattle, blood leptin levels increase and remain elevated until the end of pregnancy. However, further studies are needed to understand leptin’s role in fat production and metabolism. This study aimed to investigate the serum concentrations of leptin and insulin and their relationship with the lipid profile in Holstein cows before and after parturition. This basic experimental research was conducted on 50 pregnant Holstein cows kept in industrial cattle farm in Bagmalek from April 1402 to January 1402. Serum samples were collected from these cows two weeks before and after calving. The levels of leptin, insulin, triglycerides, cholesterol, HDL, and LDL were measured using ELISA kits and medical diagnostics. The findings indicated a decrease in leptin and insulin levels in cows after calving, along with an increase in triglyceride, cholesterol, and LDL levels compared to pre-calving levels (P˂0.05). Data analysis showed a strong positive correlation between blood leptin and insulin concentrations. Additionally, changes in leptin concentration were influenced by triglyceride (r=0.80), cholesterol (r=0.67), and LDL (r=0.63). Insulin concentration was also significantly correlated with triglyceride (r=0.52), cholesterol (r=0.67), and LDL (r=0.63). The reduction in leptin and insulin levels appears to be related to the increase in triglyceride, cholesterol, and LDL levels.