271. Effect of season on sow ovarian morphology

2008 ◽  
Vol 20 (9) ◽  
pp. 71
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Ovarian Tissue ◽  
Developmental Competence ◽  
Corpora Lutea ◽  
Ovarian Weight ◽  
Antral Follicles ◽  
Oocyte Developmental Competence ◽  
Ovarian Morphology ◽  
The Difference ◽  
Seasonal Infertility ◽  
Farrowing Rate

Reduced farrowing rate caused by embryonic mortality is a manifestation of seasonal infertility in pigs. The ability of the oocyte to mature, be fertilised and sustain embryonic development is acquired gradually by the oocyte throughout folliculogenesis. This study was undertaken to determine if seasonal differences in ovarian morphology are associated with reduced reproductive performance displayed during seasonal infertility. Sows culled after weaning were sourced from two genetically distinct herds (Farms A and B). Pairs of ovaries were collected from sows 4 days post-weaning during winter (n = 131) and summer (n = 275). Ovarian weight (Farm A only) and the numbers of small (3–4 mm) and large (5–8 mm) follicles were assessed (Farms A and B). Data did not follow normality and was analysed using the Mann–Whitney test. Mean ovarian weight per sow during winter (20.0 ± 1.3 g) was significantly heavier than that during summer (15.3 ± 0.8 g; P < 0.05). Farm A ovaries had a greater total number of antral follicles in winter compared with summer, and a greater number of antral follicles in winter compared with Farm B ovaries (P < 0.05). In Farm A ovaries, the proportion of follicles that were large was greater in summer compared with winter (78% v. 66%; P < 0.05), but the follicular distribution did not change with season in Farm B ovaries. While the findings demonstrate that ovarian weight was greater in winter compared with summer, they suggest that this difference was not the result of changes in the number or distribution of surface antral follicles. The difference in ovarian weight is possibly due to differences in ovarian tissue resulting from regressed corpora lutea. Further studies are being undertaken to assess the effect of season on oocyte developmental competence and the steroid content of follicular fluid isolated from small and large follicles.

EFFECTS OF SODIUM PENTOBARBITONE ADMINISTRATION ON GONADOTROPHIN RELEASE, FIRST OVULATION AND OVARIAN MORPHOLOGY IN PUBERTAL RATS

1976 ◽  
Vol 68 (3) ◽  
pp. 431-437 ◽  
Author(s):  
P. OSMAN ◽  
H. M. A. MEIJS-ROELOFS
Keyword(s):  
Oocyte Maturation ◽  
Cumulus Cells ◽  
Female Rats ◽  
Corpora Lutea ◽  
Follicular Growth ◽  
Adult Rats ◽  
Antral Follicles ◽  
Ovarian Morphology ◽  
Ovulatory Process

SUMMARY Pubertal female rats received sodium pentobarbitone (PB; 45 mg/kg body wt) at various hours on the day of first pro-oestrus. Maximal blockade of ovulation, in about 60% of the rats, occurred after PB treatment at 12.00, 13.00 and 14.00 h. The number of small antral follicles (100–499 × 105 μm3) was reduced 1 day after PB treatment in both blocked and ovulating rats. In the ovaries of non-ovulating rats signs of stimulation by LH such as dispersion of cumulus cells, oocyte maturation and early luteinization were sometimes present; in ovulating rats cystic corpora lutea with entrapped ova were found in addition to normal corpora lutea. Gonadotrophin measurements after PB treatment (14.00 h) in pubertal and adult rats showed (at 17.00 h) reduced levels of both LH and FSH, these levels being lower in the adults. Gonadotrophin levels of blocked and ovulating pubertal rats overlapped. In PB-treated, pubertal rats in which ovulation was postponed by 1 day, vaginal oestrus was prolonged by 1 day and the subsequent dioestrus by 2 days. The pubertal rat is thus less sensitive to PB treatment than the adult. PB treatment of the younger animal influences not only the ovulatory process but also follicular growth and, presumably, the length of the approaching cycle.

scholarly journals Oocyte developmental competence in a bovine model of reproductive aging

Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Pritpal S Malhi ◽  
Gregg P Adams ◽  
Reuben J Mapletoft ◽  
Jaswant Singh
Keyword(s):  
Embryo Transfer ◽  
Age Groups ◽  
Blastocyst Stage ◽  
Pregnancy Rates ◽  
Developmental Competence ◽  
Corpora Lutea ◽  
Reproductive Aging ◽  
Embryo Production ◽  
Embryo Survival ◽  
Oocyte Developmental Competence

The study was designed to test the hypothesis that aging in cattle is associated with reduced developmental competence of oocytes. The hypothesis was tested by comparing embryo production and pregnancy rates between 13- to 16-year-old cows (n = 6 in Year 1 and n = 9 in Year 2) and their 3- to 6-year-old young daughters (n = 8 in Year 1 and n = 9 in Year 2) after superovulation and transfer of embryos into an unrelated group of young recipients. Embryos were transferred into 2- to 5-year-old recipient cows (n = 99) as singletons (n = 45) or in pairs (n = 54 pairs). Embryo survival in recipients was determined by ultrasonography and by the number of calves born. Between old versus young cows, the number of ovulations (31 ± 4 vs 38 ± 3; P = 0.2) and the number of corpora lutea (25 ± 3 vs 29 ± 2; P = 0.3) did not differ, but fewer (P = 0.04) embryos were recovered from old cows (6 ± 2) than their daughters (12 ± 2). A higher proportion (P < 0.0001) of unfertilized oocytes/uncleaved zygotes were recovered from old cows (222/312, 71%) than their daughters (119/316, 38%). Among the embryos recovered, the proportion of International Embryo Transfer Society Grades 1–2 embryos was similar (P = 0.9) between old (59/90, 66%) and young cows (130/194, 67%). The survival of embryos after transfer into recipients, and the proportion of calves born were also similar between old and young cows. In conclusion, recovery of fewer embryos and a greater proportion of unfertilized oocytes/uncleaved zygotes suggest reduced developmental competence of oocytes from old cows, but there was no difference between age groups in embryo survival after the morula/blastocyst stage.

Oocyte developmental competence is reduced in sows during the seasonal infertility period

2010 ◽  
Vol 22 (8) ◽  
pp. 1222 ◽  
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Follicular Fluid ◽  
Late Summer ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Progesterone Concentration ◽  
Developmental Potential ◽  
Oocyte Developmental Competence ◽  
The Mean ◽  
Time Of Year ◽  
Seasonal Infertility

The modern domestic sow exhibits a period of impaired reproductive performance during the late summer and early autumn months, known as ‘seasonal infertility’. A reduction in farrowing rate due to pregnancy loss is the most economically important manifestation of seasonal infertility. The aim of the present study was to determine whether there are changes in oocyte developmental competence associated with season. Ovaries were collected in pairs from sows sourced from commercial piggeries and slaughtered 4 days after weaning during winter and summer–autumn. Following oocyte IVM and parthenogenetic activation, the ability of oocytes from large follicles to form blastocysts was greater in winter (54.94 ± 6.11%) than in summer (21.09 ± 5.59%). During winter, the proportion of oocytes developing to the blastocyst stage from large follicles was significantly higher (54.94 ± 6.11%) than those oocytes from small follicles (23.17 ± 6.02%). There was no effect of season on the proportion of oocytes developing to the blastocyst stage from small follicles. There was no effect of follicle size on blastocyst formation from those oocytes recovered during summer. Blastocysts derived from small follicles during summer had the lowest number of cells (24.25 ± 1.48) compared with blastocysts derived from large follicles during winter (37.5 ± 1.3; P < 0.05). The mean progesterone concentration in follicular fluid collected from small follicles was greater in winter than summer (1235.55 ± 164.47 v. 701.3 ± 115.5 nmol L–1, respectively; P < 0.001). The mean progesterone concentration in the follicular fluid of large follicles was also greater in winter than in summer (2470.9 ± 169.1 v. 1469.2 ± 156.5 nmol L–1, respectively; P < 0.001). Regression analysis revealed a positive correlation between progesterone concentration and oocyte developmental competence. The results indicate that porcine oocytes fail to reach their full developmental potential during the period of seasonal infertility, suggesting that the pregnancy losses observed at this time of year may be due to reduced oocyte developmental competence.

129. REDUCED OOCYTE DEVELOPMENTAL COMPETENCE DURING THE PERIOD OF SEASONAL INFERTILITY IN PIGS

2009 ◽  
Vol 21 (9) ◽  
pp. 48
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Linear Mixed Model ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Seasonal Effects ◽  
Cumulus Expansion ◽  
Developmental Potential ◽  
Parthenogenetic Activation ◽  
Oocyte Developmental Competence ◽  
Generalised Linear Mixed Model ◽  
Seasonal Infertility

Reduced farrowing rate due to early pregnancy loss is a manifestation of seasonal infertility in pigs. It has been hypothesised that the early disruption of pregnancy is due to poor oocyte developmental competence. The aim of this study was to determine if there are seasonal differences in oocyte developmental competence. Ovaries were collected from sows slaughtered 4 days after weaning. Cumulus-oocyte complexes (COCs) recovered from small (3–4mm) and large (5–8mm) antral follicles were morphologically graded and subjected to parthenogenetic activation following in vitro maturation (IVM) during the winter (n = 1419) and summer (n = 2803). Cumulus expansion was assessed subsequent to IVM. Data were analysed using a generalised linear mixed model in GenStat release 10. There was an effect of season on oocyte grade, with a larger proportion of oocytes collected in summer being graded suitable for IVM, compared with winter oocytes (P<0.05). A larger proportion of COCs had expanded cumulus during the winter than in the summer, which suggested that the preovulatory LH surge had already occurred. There was a season x follicle size interaction affecting cumulus expansion (P<0.05). There were no seasonal effects on the proportion of oocytes reaching metaphase II or cleaving after parthenogenetic activation. However, the proportion of oocytes from large follicles that developed to the blastocyst stage was higher in winter than in summer (55% vs 23%; P<0.05). There was no effect of season on the proportion of oocytes developing to the blastocyst stage from small follicles. However, during summer there was a reduction in the cell number of blastocysts derived from small follicles (P<0.05). Our results suggest that porcine oocytes are less able to reach their full developmental potential during the period of seasonal infertility, and that the associated pregnancy losses are due to reduced oocyte developmental competence.

Immunocytochemical demonstration of oxytocin in bovine ovarian tissues

1985 ◽  
Vol 109 (4) ◽  
pp. 537-542 ◽  
Author(s):  
Th. A. M. Kruip ◽  
H. G. B. Vullings ◽  
D. Schams ◽  
J. Jonis ◽  
A. Klarenbeek
Keyword(s):  
Acetic Acid ◽  
Corpus Luteum ◽  
Granulosa Cells ◽  
Ovarian Tissue ◽  
Picric Acid ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Antral Follicles

Abstract. The presence of oxytocin in ovarian tissue was examined immunocytochemically. Bovine antral follicles and corpora lutea were fixed with glutaraldehyde, picric acid and acetic acid fixative and immuno-stained by the indirect peroxidase-antiperoxydase (PAP) technique. Immunoreactive oxytocin was demonstrated in the granulosa cells of small and large follicles, in the granulosalutein cells of the young corpus luteum and in the large luteal cells of the mature corpus luteum. The regressing corpus luteum was not stainable. It is discussed that these findings additionally support the view that oxytocin is actually synthesized in ovarian tissues.

scholarly journals Impact of the LH surge on granulosa cell transcript levels as markers of oocyte developmental competence in cattle

Reproduction ◽  
2012 ◽  
Vol 143 (6) ◽  
pp. 735-747 ◽  
Author(s):  
Isabelle Gilbert ◽  
Claude Robert ◽  
Christian Vigneault ◽  
Patrick Blondin ◽  
Marc-André Sirard
Keyword(s):  
Transcript Abundance ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Follicle Cells ◽  
Transcriptomic Response ◽  
Lh Surge ◽  
Oocyte Developmental Competence ◽  
The Difference

In the case of in vitro embryonic production, it is known that not all oocytes detain the developmental capacity to form an embryo. This capacity appears to be acquired through completion of folliculogenesis, during which the oocyte and follicular cells influence their respective destinies. The differentiation status of granulosa cells (GCs) could therefore offer an indicator of oocyte quality. The aim of this study was to compare mRNA transcript abundance in GCs associated with oocytes that subsequently reach or not the blastocyst stage. GCs were collected from cattle following an ovarian stimulation protocol that did or did not include the administration of LH. GCs were classified according to the developmental stage achieved by the associated oocytes. Transcript abundance was measured by microarray. Follicles (n=189) obtained from cows before and after the LH surge were essentially similar and the rates of oocytes reaching the blastocyst stage were not significantly different (52 vs 41%), but blastocyst quality was significantly better in the post-LH-surge group. In GCs from the pre-LH-surge group and associated with developmentally competent oocytes, 18 overexpressed and 22 underexpressed transcripts were found, including novel uncharacterized transcripts, whereas no differentially expressed transcripts were associated with developmentally different oocytes in the post-LH-surge group. The novel transcriptomic response associated with LH appeared to mask the difference. Based on oocyte developmental competence, the period prior to the LH surge appears best suited for studying competence-associated mRNA transcripts in bovine follicle cells.

ABSENCE OF COMPENSATORY OVARIAN HYPERTROPHY IN RATS WITH ANTERIOR HYPOTHALAMIC LESIONS

1961 ◽  
Vol 36 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Béla Flerkó ◽  
Vera Bárdos
Keyword(s):  
Essential Role ◽  
Ovarian Tissue ◽  
Vaginal Smear ◽  
Corpora Lutea ◽  
Vaginal Smears ◽  
Hypothalamic Area ◽  
Unilateral Ovariectomy ◽  
Hypothalamic Lesions ◽  
Oestrogen Level ◽  
Stimulation Of

ABSTRACT Absence of compensatory ovarian hypertrophy in »constant oestrus rats« from lesions in the anterior hypothalamic area suggests that nervous elements localized in this region play an essential role in the stimulation of gonadotrophin output by diminution of the blood oestrogen level. The constant vaginal oestrus after unilateral ovariectomy in the majority of animals was, however, repeatedly interrupted by vaginal smears of a dioestrous type. The appearance of a dioestrous vaginal smear in the »hypothalamic constant oestrus rats« is often associated with some luteinisation. It is assumed that diminution of the blood oestrogen level by reduction of ovarian tissue in these animals may bring about a release of LH sufficient to cause formation of corpora lutea.

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