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1

Effect of different estrus synchronization systems on embryo quality in multiparous sows and prepuberal gilts

100%
Antosik P., Kempisty B., Bukowska D., Lianeri M., Biezynski J., Jaskowski J. M., Olechnowicz J.
Medycyna Weterynaryjna
|
2010
|
tom 66
|
nr 04
251-256
The aim of this study was to assessed the differences in embryos quality between the natural estrus and two systems of estrus synchronization in multiparous sows and prepuberal gilts. In this experiment, multiparous sows (n = 63) and prepuberal gilts (n = 42) were used. The subgroups of these animals were treated with PMSG (1500 U.I.) + hCG (500 U.I.) or PG-600 synchronization systems. These animals were inseminated twice, 24 and 36 h after hCG injection. The control gilts (n = 20) were from the third subgroup and were inseminated two times at 12 h intervals during their natural estrus cycles. A statistically significant increased number of corpora lutea (CL) and embryos was observed between natural estrus and both synchronization systems in multiparous sows (p < 0.001). There were no differences found in the number of degenerative embryos isolated from both ovaries between PMSG + hCG, PG-600, and natural estrus groups in multiparous sows (p = 0.484), (p = 0.279), (p = 0.213), (p = 0.138), respectively. However, an increased number of unfertilized oocytes in multiparous sows after treatment with PMSG + hCG as compared to control animals (p = 0.041) was observed. A statistically higher number of embryos after treatment with PMSG + hCG was also observed in the separate groups of multiparous sows and prepuberal gilts as compared to PG-600 treated animals. No differences were found, however, in the number of degenerative embryos between those two separate groups of animals after treatment with PMSG + hCG and PG-600 of both ovaries: (p = 0.175), (p = 0.344), (p = 0.122), and (p = 0.055), respectively. It can be suggested that the differences in the number of embryos isolated from both ovaries after these two treatments systems in prepuberal gilts and multiparous sows may be a result of age-dependent different response to gonadotropins and the reproductive competence of these females.
2

The influence of boar pheromones on the contractile reactivity of the isolated superficial veins of the nose and face in ovariectomized prepubertal gilts and in gilts during sexual maturation

84%
Grzegorzewski W. J.
Polish Journal of Veterinary Sciences
|
2006
|
tom 09
|
nr 2
This study was designed to establish: a) whether boar pheromones, 5a-androstenone and 5a-an- drostenol, may affect the contractile reactivity of superficial veins of the face in prepubertal gilts deprived of ovarian hormones, and b) what is the influence of ovarian hormones secreted during sexual maturation on the contractility of these veins. The isolated rings of frontal, facial and dorsal nasal veins were treated with androstenone (5a-androst-16-en-3-one), androstenol (5a-androst-16-en-3-ol) and testosterone (17ß-hydroxy-4-androsten-3-one) in concentrations of either 1 or 10 μM. Changes in the contractile activity of the isolated vein segments were measured using isometric transducer and recorded on HSE-ACAD W software. Sex boar pheromones androstenol and androstenone affected the contractility of the superficial veins of the face and nose in both of the prepubertal ovariectomized gilts and prepubertal intact animals. The way these veins reacted to pheromones differed between animal groups, particular vessels and even their parts and was also dose - dependent. In prepubertal ovariectomized gilts, androstenol had stronger action and caused the constriction of the facial vein, dorsal nasal vein and the distal part of the frontal vein. Androstenone produced constriction of the nasal vein, distal part of the frontal vein and proximal part of facial vein, but relaxation of the proximal part of the frontal vein and the distal part of the facial vein. In prepubertal untreated gilts, androstenone was more effective and strongly influence on the constricted of the frontal vein and facial vein and produced the relaxation of the nasal vein. Androstenol influence on the constriction the frontal vein and the distal parts of the facial vein and nasal vein, and influence o the relaxtion their proximal parts. Testosterone used as a control androgen affected both superficial veins of the face veins in a dose-dependent manner, and, at a higher dose, increased the contractility more effectively. Only the nasal vein did not react to this hormone. The present results suggest the existence in prepubertal gilts of frontal and facial veins' specific reactivity which may participate in the regulation of blood flow from the nasal cavity to the peri- hypophyseal vascular complex and play a role in the humoral pathway for the male pheromone priming functions in the central nervous system. This reactivity was displayed by the vessels in prepubertal gilts without ovarian hormones. The presence of active ovaries in maturing gilts changed the reactivity of these veins to pheromones and testosterone.
3

Effect of zearalenone on steroid secretion by porcine follicular cells in mono- and coculture

67%
Jakimiuk E., Gajecka M., Jana B., Obremski K., Gajecki M.
Bulletin of the Veterinary Institute in Puławy
|
2010
|
tom 54
|
nr 3
The objective of the study was to evaluate the impact of zearalenone (ZEA) on the production and secretion of some steroid sex hormones by granulosa cells in monoculture and granulosa cells with theca interna cells in coculture. Follicular cells were obtained from ovarian follicles of pre-pubertal gilts. They were exposed to 0.2% DMSO and ZEA (at a concentration of 0.4, 4, 40, and 400 ng/mL), for 48 h. The concentration of progesterone, testosterone, and oestradiol-17ß in the medium was determined by radioimmunoassay. It was found that both stimulating and inhibitory effect of ZEA on basal steroidogenesis in porcine ovarian follicular cells was depended on the type of cultures and concentrations of mycotoxin.
4

Selected hormonal parameters in prepubertal gilts treated with Escherichia coli endotoxin

67%
Jana B.
Polish Journal of Veterinary Sciences
|
1999
|
tom 02
|
nr 1
The present study was designed to examine the influence of Escherichia coli endotoxin (LPS, lipopolysac- charide) on the concentration of gonadotrophin-releasing hormone (GnRH) in the hypothalamus and luteinizing hormone (LH) in the pituitary as well as LH, prolactin (PRL), Cortisol (CI), and sex steroids in blood plasma of prepurtal gilts. In the ovaries, LH/human chorionic gonadotropin (hCG) receptors content was also estimated. The experiment was performed on 10 prepubertal gilts (Large White x Landrace) at the age of 156 ± 2 days (body weight 65.7 ± 3.56 kg, mean + SD). The animals were randomly assigned to one of two groups: 1) treated with Escherichia coli endotoxin (serotype 055:B5; n = 5), and 2) control gilts receiving saline (n = 5). 2 mg of LPS was administered i.m., twice a day (at 08:05 and 20:05) for 4 days. Blood samples from the jugular vein were collected every hour for 12 h (08:00/time 0 - 20:00), for 4 days of the study and more frequently during 4 h (08:00/time 0 - 12:00) sampling periods every day of the experiment. All the gilts were slaughtered on the next day, after the last LPS or saline injections were performed and then, the ovaries, hypothalamus and pituitary were immediately dissected out. Plasma and tissue hormone concentrations were analysed by radioimmunoassay (RIA). During the experimental period, rectal temperature in LPS-treated gilts was higher (on the 1st' and 2nd day - P < 0.001, on the 3th and 4th day - P < 0.05) than that found in the controls. During the whole experiment mean concentrations of CI in the gilts treated with LPS were higher (P < 0.05 - P < 0.001) in comparison to those observed in the controls. In the gilts receiving LPS, plasma LH was lower (P < 0.01, P < 0.001) than that found in the control animals on days 1-4 of the study. Injections of LPS did not affect the frequency, amplitude or duration of LH peaks. In LPS-treated group, plasma PRL was decreased (P < 0.05, P < 0.01) on the 4th day of the experiment in comparison to that found in the control group. During the consecutive days of the study, the levels of androstenedione (A4), testosterone (T) and estradiol-17ß (E2) remained unchanged in both control and LPS-treated gilts and no significant differences between both groups were found. GnRH content in the hypothalamus and LH in the pituitary varied insignificantly between the groups showing tendency to a slight decrease in the gilts receiving LPS. In the ovaries of LPS-treated animals, the concentration of LH/hCG receptors slightly decreased as compared with that found in the control gilts. The results obtained indicate that administration of LPS to prepubertal gilts causes a decrease in plasma LH and PRL concentrations, an increase in Cortisol level and a slight decrease in numbers of LH/hCG receptors in the ovaries. These findings suggest also that pathological states altering secretion of the pituitary hormones can impair processes leading to puberty in a female.
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