Vol. 9, Special Issue 2, Part G (2025)

Metabolic processes in ruminants, including sheep, differ from those in monogastric animals due to their unique digestive system, which relies on microbial fermentation to produce volatile fatty acids (VFAs) as primary energy sources. Hepatic gluconeogenesis serves as the principal mechanism for glucose production in sheep, including during fetal development. The present study investigated the biochemical composition of serum and follicular fluid in ewes across different age groups (<1 year and >1 year) during breeding and non-breeding seasons to elucidate metabolic variations associated with reproductive status and environmental conditions. A total of 16 ewes were selected from a civil slaughterhouse in Bangalore, India, and categorized based on seasonality and age. Serum and follicular fluid samples were analyzed for biochemical metabolites, electrolytes, and enzymatic markers using commercially available diagnostic kits. The results indicated significant differences (p<0.05) in the concentrations of several biochemical constituents between serum and follicular fluid across age groups and seasons. Protein and albumin levels were higher in serum, while HDL, cholesterol, and triglycerides exhibited elevated concentrations in follicular fluid. Urea concentrations were significantly higher in follicular fluid, suggesting active transport or local synthesis. Seasonal variations influenced metabolic markers, with pregnant ewes during the breeding season displaying lower serum glucose and elevated β-hydroxybutyrate (BHBA) levels, indicative of a negative energy balance. Additionally, increased aspartate aminotransferase (AST) activity suggested hepatic stress in pregnant ewes, exacerbated by environmental factors such as winter cold stress. These findings provide critical insights into the metabolic regulation of serum and follicular fluid in ewes, contributing to a better understanding of ovarian function and reproductive physiology. The study highlights the impact of seasonality and pregnancy on metabolic homeostasis, emphasizing the importance of nutritional and environmental management in improving reproductive efficiency in sheep.