Bioscientifica Proceedings

In vitro maturation and in vitro fertilization techniques in pigs have progressed considerably in recent years. Many reports focus on the factors affecting in vitro maturation that lead to normal male pronuclear formation or monospermy after fertilization in vitro. It is suggested that pig follicular fluid (pFF), follicle somatic cells and various hormones are important factors for the maintenance of cytoplasmic maturation of oocytes <e...

Neurophysiological mechanisms that control energy balance are reciprocally linked to those that control reproduction. Neuromorphological studies using retrograde tracing methods revealed that nerve cells within the central (CNS) and autonomic (ANS) nervous systems in different species, including the pig, are transsynaptically connected to different fat tissue depots. In the pig, neurons localised in the paraventricular nucleus, supraoptic nucleus and arcuate nucleus were...

The formation of primordial follicles to establish a reservoir of resting follicles and the gradual depletion of that reservoir to provide a succession of growing follicles are key to female fertility, but little is known about the regulation of these early stages of follicular development. This review summarizes the efforts of our laboratory to elucidate these critical processes in cattle. Primordial follicles first appear in fetal ovaries around the end of the first trimeste...

Summary. Exposure of male and female pigs to elevated ambient temperatures can result in reduced reproductive efficiency. When boars and gilts are exposed to heat stress, respiratory rates increase to enhance evaporative cooling because minimal sweating occurs.During early pregnancy, gilts are especially susceptible to heat stress. Decreased conception rates and reduced litter size occur when gilts are exposed to elevated ambient te...

Keywords: pig; models; metabolism© 1990 Journals of Reproduction & Fertility Ltd...

The number of female germ cells in pig fetuses decreases by 70% between day 50 after mating and day 300 after birth. Approximately 55% of antral follicles undergo degeneration (atresia) except during the 3 days before oestrus, when only 15% of the follicles survive to ovulate. Apoptosis, a form of programmed cell death, is recognized as the mechanism of germ cell death and follicle atresia at all stages of folliculogenesis. The internucleosomal cleavage of genomic DNA ca...

Studies in different animal models and humans give evidence that stress experienced by pregnant mothers affects foetal development and has long-term consequences on many physiological systems and behaviour in the offspring, thus facilitating the risk for disorders later in life. In farm animals, housing conditions or inadequate management practices during gestation may be potential stressors for the mother, which could affect growth, vitality, health and welfare of the d...

Light microscopic semen evaluation provides useful information about a given sperm sample, but due to its subjective nature has limited prognostic value for the reproductive performance of males or the outcome of assisted fertilization. Cryptic sperm abnormalities (occurring at the molecular level) are not easily detectable by light microscopy, but can be revealed by an array of biomarkers. The latter include fluorescent markers of acrosomal status, fluorochromes detecting alt...

The bovine corpus luteum (CL) grows very fast and regresses within a few days at luteolysis. Mechanisms controlling development and secretory function of the bovine CL may involve many factors that are produced both within and outside the CL. In the cow, luteolysis is initiated by uterine prostaglandin (PG)F2α released at the late luteal stage. It can also be induced by injection of exogenous PGF2α given at the mid luteal stage. Luteolysis consi...

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