Bone morphogenetic protein 15 intrafollicular injection inhibits ovulation in cattle.

Oocyte-derived bone morphogenetic protein 15 (BMP15) is one of the main local regulators of ovarian physiology, but its role in the regulation of preovulatory follicles and ovulation is not well established. Therefore, this study was conceived to determine the effect of intrafollicular injection (IFI) of BMP15 on final follicular growth, ovulation and luteinization in cattle. Initially, it was observed that relative mRNA abundance of the BMP15 receptor BMPR1B in granulosa cells was regulated by GnRH treatment, and it was negatively correlated (R = 0.

Effect of recombinant bovine somatotropin (rbST) treatment on follicular population and development in non-lactating dairy cows.

The aim of this study was to evaluate the long-term effects of recombinant bovine somatotropin (rbST) on follicle population and ovulatory follicle development in non-lactating dairy cows. Twenty-one Jersey cows were allocated in rbST (n=11) or control (n=10) groups. On day -60, cows in rbST group received 500 mg of somatotropin (s.

Effect of butafosfan supplementation during oocyte maturation on bovine embryo development.

Around 60-80% of oocytes maturated in vivo reached competence, while the proportion of maturation in vitro is rarely higher than 40%. In this sense, butafosfan has been used in vivo to improve metabolic condition of postpartum cows, and can represent an alternative to increase reproductive efficiency in cows. The aim of this study was to evaluate the addition of increasing doses of butafosfan during oocyte maturation in vitro on the initial embryo development in cattle.

Effect of high-density lipoprotein on oocyte maturation and bovine embryo development in vitro.

High-density lipoprotein (HDL) is the main lipoprotein in the follicular fluid, and it has anti-inflammatory, antioxidant and cryoprotectant properties. The anti-inflammatory potential and antioxidant potential are derived from its lipid composition, especially the apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1). The aim of this study was to evaluate the effect of HDL during in vitro maturation (IVM) on oocyte maturation and early bovine embryo development.

Effect of serum paraoxonase-1 (PON1) activity on follicular development and pregnancy rate in cattle.

Paraoxonase-1 (PON1) activity has been associated with improvement in ovarian function in early postpartum dairy cows and improved in vitro embryo development. The aim of the current study was to evaluate the potential association among PON1 activity and follicular growth, diameter of the preovulatory follicle and pregnancy per artificial insemination (AI) service in cattle. In Experiment 1, cows (n=33) were subjected to an estradiol-progesterone based protocol to control time of ovulation.

The acute effect of intravenous lipopolysaccharide injection on serum and intrafollicular HDL components and gene expression in granulosa cells of the bovine dominant follicle.

The aim of this study was to evaluate the effect of an acute systemic inflammatory response induced by lipopolysaccharide (LPS) in the serum and follicular fluid (FF) high-density lipoprotein (HDL) components, hormone concentrations and granulosa cell gene expression. For this purpose, twenty non-lactating Jersey dairy cows were submitted to a progesterone (P4) - estradiol (E2) based synchronization protocol. Cows received a single i.

Selection of porcine oocytes in vitro through brilliant cresyl blue staining in distinct incubation media.

Staining with brilliant cresyl blue (BCB) may be used for oocyte selection, but BCB staining itself and the most commonly used selection medium (DMPBS) may compromise the development of porcine oocytes in vitro. This study evaluated DNA fragmentation, nuclear maturation, the area of migration of cortical granules (CG) and embryo development for stained (BCB+) and unstained (BCB-) oocytes incubated in DMPBS and in a modified medium (ReproPel) tested for the first time. Unexposed (UN), BCB+ and BCB- oocytes were incubated composing six groups: DMPBS/UN; DMPBS/BCB+; DMPBS/BCB-; ReproPel/UN; ReproPel/BCB+; and ReproPel/BCB-.

The effect of growth hormone (GH) and insulin-like growth factor-I (IGF-I) on in vitro maturation of equine oocytes.

The objective of this study was to test the hypothesis that equine growth hormone (eGH), in combination with insulin growth factor-I (IGF-I), influences positively in vitro nuclear and cytoplasmic maturation of equine oocytes. Cumulus-oocyte complexes were recovered from follicles that were < 25 mm in diameter, characterized by morphology and were allocated randomly as follow: (a) control (no additives); (b) 400 ng/ml eGH; (c) 200 ng/ml IGF-I; (d) eGH + IGF-I; and (e) eGH + IGF-I + 400 ng/ml anti-IGF-I antibody. Oocytes were matured for 30 h at 38.