Embryonic development, luteal size and blood flow area, and concentrations of PGF2α metabolite in dairy cows fed a diet enriched in polysaturated or polyunsaturated fatty acid.

The objective of this study was to examine effects of sunflower (SO) and palm oil (PO) supplements in the diet on embryonic development, luteal size and blood flow area, PGF2α metabolite (PGFM), and progesterone (P4) concentrations. Prepartum cows (n = 42) were randomly assigned to one of three dietary treatments (control, 4% PO, and 4% SO supplements). Animals were fed diets individually from day 28 prepartum to day 111 postpartum. Luteal size and blood flow area were determined throughout the estrous cycle by Doppler ultrasonography. Oocytes were collected in three ovum pick-up sessions at 2 week intervals for the in vitro embryo production. Oocyte characteristics and embryonic development were not affected by dietary treatments. Cows fed 4% SO had a greater (P < 0.05) concentration of PGFM from day 15 to day 35 postpartum than those cows fed 4% PO and the control group. On day 11 of the estrous cycle (mid-luteal phase), serum P4 concentrations (6.0 ±â€¯0.7, 5.7 ±â€¯0.5, and 4.7 ±â€¯0.6 ng/ml), luteal size (7.0 ±â€¯0.2, 6.5 ±â€¯0.2, and 5.3 ±â€¯0.1 cm2) and luteal blood flow area (1.3 ±â€¯0.2, 1.2 ±â€¯0.1, and 0.9 ±â€¯0.1 cm2) were greater (P < 0.05) in cows fed 4% SO and 4% PO than the control group, respectively. Thus, plant oil supplements in diets affected luteal size and serum P4 and PGFM concentrations, but not early embryonic development. Such changes in secretion of PGF2α and P4 indicate that plant oil supplements during pre- and postpartum may alter uterine and luteal functions.

Corpora lutea in superovulated ewes fed different planes of nutrition.

The corpus luteum (CL) is an ovarian structure which is critical for the maintenance of reproductive cyclicity and pregnancy support. Diet and/or diet components may affect some luteal functions. FSH is widely used to induce multiple follicle development and superovulation. We hypothesized that FSH would affect luteal function in ewes fed different nutritional planes. Therefore, the aim of this study was to determine if FSH-treatment affects (1) ovulation rate; (2) CL weight; (3) cell proliferation; (4) vascularity; (5) expression of endothelial nitric oxide (eNOS) and soluble guanylate cyclase (sGC) proteins; and (6) luteal and serum progesterone (P4) concentration in control (C), overfed (O), and underfed (U) ewes at the early- and mid-luteal phases. In addition, data generated from this study were compared to data obtained from nonsuperovulated sheep and described by Bass et al. Ewes were categorized by weight and randomly assigned into nutrition groups: C (2.14 Mcal/kg; n = 11), O (2xC; n = 12), and U (0.6xC; n = 11). Nutritional treatment was initiated 60 d prior to day 0 of the estrous cycle. Ewes were injected with FSH on day 13-15 of the first estrous cycle, and blood samples and ovaries were collected at early- and mid-luteal phases of the second estrous cycle. The number of CL/ewe was determined, and CL was dissected and weighed. CL was fixed for evaluation of expression of Ki67 (a proliferating cell marker), CD31 (an endothelial cell marker), and eNOS and sGC proteins using immunohistochemistry and image analysis. From day 0 until tissue collection, C maintained, O gained, and U lost body weight. The CL number was greater (P < 0.03) in C and O than U. Weights of CL, cell proliferation, vascularity, and eNOS but not sGC expression were greater (P < 0.001), and serum, but not luteal tissue, P4 concentrations tended to be greater (P = 0.09) at the early- than mid-luteal phase. Comparisons of CL measurements demonstrated greater (P < 0.01) cell proliferation and serum P4 concentration, but less vascularity at the early and mid-luteal phases, and less CL weight at the mid-luteal phase in superovulated than nonsuperovulated ewes; however, concentration of P4 in luteal tissues was similar in both groups. Thus, in superovulated ewes, luteal cell proliferation and vascularity, expression of eNOS, and serum P4 concentration depend on the stage of luteal development, but not diet. Comparison to control ewes demonstrated several differences and some similarities in luteal functions after FSH-induced superovulation.

Relationships among vasculature, mitotic activity, and endothelial nitric oxide synthase (eNOS) in bovine antral follicles of the first follicular wave.

To determine the relationships among vasculature, mitotic activity, and expression of endothelial nitric oxide synthase (eNOS) of antral follicles in Bos indicus, bovine ovaries were obtained on day 6 of the estrous cycle from 10 crossbred (Brahman to Thai native cows) after a synchronized estrus with prostaglandin F2α analogue. Ovaries were fixed, paraffin-embedded, and used for immunofluorescence detection of factor VIII (a marker of endothelial cells). Immunostaining of eNOS and proliferating cell nuclear antigen (PCNA) were performed with specific monoclonal antibodies. Vasculature and positive staining of eNOS and PCNA were quantitatively evaluated with the image analysis. Follicles were classified by size (small, medium, and large) and by structure as healthy and atretic follicles (n = 82). The expression of factor VIII and eNOS were detected greater in the blood vessels of the theca layers of the healthy follicles than those in atretic follicles. The labeling indices (LIs) in granulosa and theca cells were greater (P < 0.05) in the healthy small and medium follicles than in the healthy large follicles. Vasculature, capillary area density, and capillary number density were positively correlated with eNOS expression and the LIs of granulosa and theca cells but were negatively correlated with the healthy follicle size. During the growing phase of antral follicle in Bos indicus, relationships among vasculature, mitotic activity, and eNOS were observed predominantly in healthy antral follicles. Thus, these data highlight the importance of vasculature, cell proliferation, and eNOS expression of growing and atretic follicles in the first follicular wave.