title: Free fatty acid levels in fluid of dominant follicles at the preferred insemination time in dairy cows are not affected by early postpartum fatty acid stress.
abstract: The fertility of high-yielding dairy cows has declined during the last 3 decades, in association with a more profound negative energy balance (NEB) during the early weeks postpartum. One feature of this NEB is a marked elevation in circulating free fatty acid (FFA) concentrations. During the early postpartum period (≤ d 42), circulatory FFA levels were measured weekly, and progesterone concentrations and the diameter of the dominant follicles were determined thrice weekly. Retrospectively, cows that ovulated within 35 d postpartum were grouped as "normal ovulating" cows (n = 5), and the others were grouped as "delayed ovulating" cows (n = 5). In both groups, high total FFA levels (>500 µM) were evident immediately postpartum. Interestingly, cows with delayed ovulation had higher plasma FFA concentrations in the first weeks postpartum compared with normal ovulating cows. In both cow groups, FFA decreased to control levels of non-NEB cows within 3 wk postpartum. The FFA compositions and concentrations in fluids from the dominant follicles of postpartum cows were not different between the normal and delayed ovulating cows when measured at potential insemination points: d 55, 80, and 105 postpartum. Interestingly, the concentration of monounsaturated oleic acid was higher and that of saturated stearic acid lower in follicular fluids of both groups compared with that in blood. The level of FFA in follicular fluid was correlated with the ratio of 17β-estradiol (E2) to progesterone (P4) in follicular fluid, with a relatively high level of unsaturated FFA in follicles with a low E2:P4 ratio. Taken together, these results indicate that a more severe NEB early postpartum is related to a delay in the first postpartum ovulation and does not affect FFA composition in follicular fluid at the preferred insemination time. The high FFA level in dominant follicles with a low E2:P4 ratio may be due to a different FFA metabolism in these follicles. The diagnostic value of this observation for selective screening of dominant follicles needs further investigation.
authors: Department of Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands. Electronic address: H.Aardema@uu.nl.
authors: Hilde
authors: H
authors: Aardema
authors: Department of Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands; Department of Biochemistry and Cell Biology, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Bart M
authors: BM
authors: Gadella
authors: Department of Biochemistry and Cell Biology, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Chris H A
authors: CH
authors: van de Lest
authors: Department of Biochemistry and Cell Biology, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Jos F H M
authors: JF
authors: Brouwers
authors: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Tom A E
authors: TA
authors: Stout
authors: Department of Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands; Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Bernard A J
authors: BA
authors: Roelen
authors: Department of Farm Animal Health, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors: Peter L A M
authors: PL
authors: Vos
mesh_terms: D000818:Animals; D002417:Cattle; D004734:Energy Metabolism; D004958:Estradiol / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D015571:Follicular Fluid / Q000737:chemistry*; D007314:Insemination / Q000502:physiology*; D019301:Oleic Acid / Q000097:blood; D010060:Ovulation; D049590:Postpartum Period; D025341:Principal Component Analysis; D011374:Progesterone / Q000097:blood; D012189:Retrospective Studies; D013229:Stearic Acids / Q000097:blood; D013312:Stress, Physiological
chemical_list: D005230:Fatty Acids, Nonesterified; D013229:Stearic Acids; D019301:Oleic Acid; C031183:stearic acid; D011374:Progesterone; D004958:Estradiol
keywords: dairy cow; follicular fluid; free fatty acid; postpartum