Dynamics of ovarian follicular fluid in cattle

In the present study, ovarian follicular fluid metabolites, ions, enzymes and hormonal profiles in relation to follicular size in Holstein cattles were investigated. Fluid from small (4–5 mm), medium (6–9 mm) and large (10–20 mm) follicles were collected from 80 clinically healthy and non-pregnant adult cattles. Follicular fluid samples were analyzed for iron, calcium, phosphorous, sodium, potassium, magnesium, glucose, urea, creatinine, cholesterol, triglyceride, protein, albumin, globulin, alkaline phosphatase (ALK), lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), progesterone, testosterone, estradiol-17β, T3 and T4. The concentration of urea, creatinine and protein in small, medium and large follicles did not differ (P > 0.05). The concentrations of phosphorus, magnesium, cholesterol, triglyceride and albumin in follicular fluid decreased (P < 0.05) with the development of the follicle while the reverse was true for calcium, sodium, globulin and estradiol-17β concentrations (P < 0.05). Glucose concentration in small follicles was lower (P < 0.05) than that in medium and large follicles. The concentrations of iron, ALK, LDH, ALAT and ASAT were higher (P < 0.05) than in small follicles. The concentrations of potassium, progesterone and T3 in large follicles were lower (P < 0.05) than those in small and medium follicles while the reverse was true for the T4 concentration (P < 0.05).