| 1. |
- Bolarin, A., et al.
(författare)
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Use of frozen-thawed semen aggravates the summer-autumn infertility of artificially inseminated weaned sows in the Mediterranean region
- 2009
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Ingår i: Journal of Animal Science. - : American Society of Animal Science. - 0021-8812 .- 1525-3163. ; 87:12, s. 3967-3975
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Tidskriftsartikel (refereegranskat)abstract
- Improvement of farrowing rate (FR) and litter size (LS) of sows that are AI with frozen-thawed (FT) semen can hardly be reached without identification of the factors behind the high variability seen among trials. Three experiments using weaned (4-d wean-to-estrus interval) multiparous (parity 2 to 7) sows were conducted to evaluate the effect of period of the year on FR and LS of FT-inseminated sows in southern Spain. Sows were grouped into 2 periods of the year: winter-spring (November to April; WS) and summer-autumn (May to October; SA). Ovarian status was monitored by transrectal ultrasonography to record how long before or after ovulation AI was performed (pre-, peri-, or postovulatory AI) and to determine the onset of estrus-to-ovulation interval (EOI). Inseminations were performed using deep intrauterine AI with 1.5 x 109 FT sperm per dose. The first experiment was designed to determine the influence of the period of the year on FR and LS of FT semen. Sows (116 in WS and 100 in SA) were AI at 33 and 39 h after the onset of estrus. The period of the year influenced the FR and LS (P less than 0.01). Farrowing rate and LS were least in SA (P less than 0.05). This pattern of annual variation was similar to that shown by sows on the same farm currently undergoing AI with liquid semen (cervical AI at 12 and 36 h after the onset of estrus with 3 x 109 sperm per dose). However, the FR reduction in SA respect to WS was more substantial in sows artificially inseminated with FT (77.6 vs. 50%, P less than 0.001) than those artificially inseminated with liquid semen (83.9 vs. 71.8%, P less than 0.05). More pre- and less periovulatory AI were performed in SA sows than in WS sows (P = 0.05). Experiment 2 was designed to evaluate whether the period of the year influenced EOI. Ovarian status was transrectal ultrasonography scanned every 6 h after the onset of estrus until the end of ovulation (WS: 30; SA: 31 sows). There were more sows with long EOI (greater than48 h) in SA than in WS (P = 0.05). Experiment 3 aimed to improve the reduced FR and LS recorded in SA sows when using FT semen (Exp. 1) by inducing ovulation with eCG + hCG. A single AI with FT semen was performed 5 h before the expected ovulation (55 sows). As a control, spontaneously ovulating sows (n = 53) were FT-inseminated as in Exp. 1. Hormonal induction of ovulation did not improve FR and LS (P greater than 0.05). In the Spanish Mediterranean area, a longer EOI during SA negatively influenced the FR and LS of weaned sows after AI. This effect was particularly evident when FT semen was used. These findings were not ameliorated by hormonal induction of ovulation.
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| 2. |
- Cuello, C., et al.
(författare)
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Vitrification of in vitro cultured porcine two-to-four cell embryos
- 2007
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 68:2, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this experiment was to evaluate the effect of a 5-day period of in vitro culture of two-to-four cell porcine embryos up to the blastocyst stage on their ability to survive vitrification and warming. In order to increase the cooling rate, superfine open pulled straws and Vit-Master (R) technology were used for vitrification. Two-to-four cell embryos were collected from weaned sows (n = 11) on day 2 (DO = onset of estrus). Some embryos (N = 63) were vitrified within 3 It after collection, warmed and cultured for 120 h (Group V2). Additionally, 81 two-to-four cell embryos were cultured for 96 It in order to obtain blastocysts; these were then vitrified, warmed and cultured for 24 h (Group VB; N = 65). The remaining two-to-four cell embryos were used as controls and thus not vitrified (control embryos; N = 70) but were cultured in vitro for 120 h. The V2, VB and control embryos were evaluated for their developmental progression and morphology during culture. All embryos (V2, VB and controls) were fixed on the same day of development in order to assess the total number of blastomeres. The survival and blastocyst formation rates obtained from V2 embryos were very poor (9.6 +/- 0.7% and 3.2 +/- 0.5%, respectively). The survival and hatching rates of VB embryos (75.0 +/- 0.69% and 33.6 +/- 0.13%) were lower (p less than 0.001) than those obtained with control embryos (89.1 +/- 0.8% and 47.5 +/- 0.12%). Hatched VB embryos had a lower (p less than 0.01) total cell number than hatched control embryos (70.3 +/- 4.5 versus 90.6 +/- 3.2, respectively). There was no difference between expanded VB and control blastocysts. In conclusion, blastocysts derived from in vitro culture of two-to-four cell pig embryos could be successfully vitrified using SOPS straws and Vit-Master (R). (c) 2007 Elsevier Inc. All rights reserved.
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| 3. |
- Bolarin, A, et al.
(författare)
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Dissimilarities in sows ovarian status at the insemination time could explain differences in fertility between farms when frozen-thawed semen is used
- 2006
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 65:3, s. 669-680
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Tidskriftsartikel (refereegranskat)abstract
- Deep intrauterine insemination (DUI) offers a suitable alternative for the commercial use of frozen-thawed boar semen. The present study evaluated how the ovarian status at DUIs of frozen-thawed spermatozoa. (1 x 10(9) spz/dose, two DUls, 30-31 and 36-37 h after detection of oestrus) in 179 sows would explain differences in fertility between two farms with similar, but not equal, reproductive management (experiment 1). A further experiment investigated whether an increase in sperm number per AI-dose (1 versus 2 x 10(9) spz/dose, two DUls, 30-31 and 36-37 h after detection of oestrus, on 228 sows) could minimize this effect (experiment 2). Ovaries were checked by transrectal ultrasonography at the time of DUI and sows were classified into three categories: F-: ovarian pre-ovulatory follicles were visible during two examinations; O-: ovulation visible during one examination; and C-sows: corpora hemorragica visible during the two examinations. Overall farrowing rates differed (P less than 0.01) between farms (70.1 versus 51.2%, farms A and B, respectively). Distribution of sows among ultrasonography categories also differed (P less than 0.05) between farms (17.5, 72.2 and 10.3% were classified as F, O- and C-sows in farm A, versus 40.2, 29.3 and 30.5% in farm B). Nevertheless, farrowing rates and litter sizes within categories did not vary between farms (P greater than 0.05). In addition, a two-fold increase in the number of spermatozoa per DUI improved (P less than 0.05) fertility in F- and C-sows, but not in O-sows. In conclusion, the interval DUI-to-ovulation provides a major explanation for fertility differences between farms when frozen-thawed spermatozoa are used. (c) 2005 Elsevier Inc. All rights reserved.
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| 4. |
- Caballero, Ignacio, et al.
(författare)
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Immunolocalization and possible functional role of PSP-I/PSP-II heterodimer in highly extended boar spermatozoa
- 2006
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Ingår i: Journal of Andrology. - : American Society of Andrology. - 0196-3635 .- 1939-4640. ; 27:6, s. 766-773
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Tidskriftsartikel (refereegranskat)abstract
- PSP-I/PSP-II heterodimer is a major protein of boar seminal plasma which is able to preserve, in vitro, the viability, motility, and mitochondrial activity of highly extended boar spermatozoa for at least 5 hours. However, little is known about the binding pattern of the heterodimer to the sperm plasma membrane and its eventual relation with the maintenance of the sperm functionality. The present study investigated the effect of exposing highly extended boar spermatozoa (11 million/mL) to 1.5 mg/mL of PSP-I/PSP-II for 0.5, 5, and 10 hours at 38 degrees C on sperm characteristics and the changes in PSP-I/PSP-II localization as a result of both the addition of PSP-I/PSP-II to the extender and the incubation time. Exposure of the spermatozoa to PSP-I/PSP-II preserved sperm viability, motility, and mitochondrial activity when compared to nonexposed spermatozoa. This protective effect lasted for 10 hours (P less than.05). After immunolabeling of highly extended semen with rabbit monospecific polyclonal antibody against PSP-I/PSP-11, the percentage of immunopositive spermatozoa declines over time from 71% (0.5 hours) to 49% (10 hours). However, more than 80% of spermatozoa remained labeled during the 10-hour incubation period if PSP-I/PSP-11 was added. Scanning electron microscopy revealed 4 different binding patterns. The heterodimer was mainly localized to the acrosomal area, being redistributed to the postacrosomal area or lost during in vitro incubation. In conclusion, the protective effect of the heterodimer appears to be related to its adhesion to the acrosomal area, and the loss of this protective effect coincides with a stepwise redistribution of PSP-I/PSP-II during incubation.
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| 5. |
- Garcia, E.M., et al.
(författare)
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Localization and expression of spermadhesin PSP-I/PSP-II subunits in the reproductive organs of the boar
- 2008
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Ingår i: International Journal of Andrology. - : Wiley-Blackwell. - 0105-6263 .- 1365-2605. ; 31:4, s. 408-417
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Tidskriftsartikel (refereegranskat)abstract
- The epithelial localization and expression of the spermadhesin PSP-I and PSP-II subunits were determined in the testis, ductus epididymes (caput, corpus and cauda), seminal vesicles and bulbourethral glands of mature boars, using immunohistochemical, western blotting and RT-PCR methods. Immunohistochemistry showed positive labelling for PSP-I and PSP-II antibodies in the epithelium of seminal vesicles in all males tested. Positive immunolabelling, but with variable intensity, was also present in the epididymal epithelium (caput, corpus and cauda), although varying largely among segments and boars. Immunoreactivity was nearly or completely absent in the seminiferous epithelium and the bulbourethral gland, although SDS-PAGE and western blotting revealed the presence of PSP-I and PSP-II immunoreactive bands in all the tissue extracts, including the testis and the bulbourethral gland. mRNA amplification by RT-PCR using primers specific for PSP-I and PSP-II showed a trend similar to that observed for western blotting, i.e. intensity variation between tissues (even between segments of the same epididymis) and among boars. Our results indicate that the seminal vesicles are the main source of PSP-I and PSP-II spermadhesins, although epididymal segments, testis and the bulbourethral gland also participate in the expression of both proteins.
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| 6. |
- Hernandez, Marta, et al.
(författare)
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Differences in SCSA outcome among boars with different sperm freezability
- 2006
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Ingår i: International Journal of Andrology. - : Wiley-Blackwell. - 0105-6263 .- 1365-2605. ; 29:6, s. 583-591
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Tidskriftsartikel (refereegranskat)abstract
- Spermatozoa from some boars sustain the process of cryopreservation poorly and yield poor fertility after artificial insemination. Poor freezability has not been disclosed using conventional semen analyses. A defective chromatin can, if present in a substantial number of spermatozoa, affect the fertilizing ability of spermatozoa. Here we tested the hypothesis that nuclear DNA instability could explain differences in freezability among boars, and complement or supersede conventional tests for sperm quality such as sperm motility or membrane assessments. Frozen-thawed (FT) spermatozoa from a total of 44 stud boars were assessed by the sperm chromatin structure assay (SCSA), in relation to computer-assisted sperm analysis-derived sperm motility variables and sperm viability (triple fluorescent microscopic staining), including three experiments. The first trial, including 24 boars, evaluated the relationship between the sperm motility and viability with levels of DNA integrity. The SCSA showed that most spermatozoa had intact DNA [levels of DNA fragmentation index (%DFI) ranging from 0.63% to 11.85%] significantly correlated (albeit weakly) with current sperm quality variables. The second trial, on 15 boars, assessed the influence of two different thawing rates (20 s at 37 degrees C vs. 8 s at 70 degrees C) and the post-thaw incubation times (0, 30, 150 and 300 min) at 37 degrees C on FT-boar sperm quality. The highest sperm survival (p less than 0.05) and the lowest DNA damage (p less than 0.01) were achieved when thawing was carried out at 70 degrees C for 8 s, without any change during the first 150 min of incubation. Finally, the third experiment studied if differences in sperm freezability showed by stud boar semen, as good or bad freezers by conventional analyses, could be attributed to differences in chromatin structure. All SCSA parameters were low, but significantly (p less than 0.05-0.001) higher for bad freezers, showing they had less homogeneous sperm chromatin than the good freezers. The results indicate that SCSA outcome complements conventional assessment of FT-boar spermatozoa, disclosing differences in their ability to sustain freezing and thawing. However, the low overall DNA damage observed in FT spermatozoa seems to have poor biological significance.
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| 7. |
- Rodriguez-Martinez, Heriberto, et al.
(författare)
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Boar spermatozoa in the oviduct
- 2005
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Ingår i: Theriogenology. - : Elsevier. - 0093-691X .- 1879-3231. ; 63:2, s. 514-535
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Tidskriftsartikel (refereegranskat)abstract
- In the pig, a functional tubal sperm reservoir (SR) is established before ovulation to ensure availability of suitable numbers of viable spermatozoa for fertilization. The boars large ejaculate is split: most spermatozoa are delivered in a sperm-rich fraction (SRF) followed by a post-SRF fraction containing increasing amounts of the spermadhesin PSP-I/PSP-II-rich seminal vesicle secretion. This heterodimer acts as leukocyte chemoattractant both in vitro and in vivo, contributing to the phagocytosis of those spermatozoa not reaching the SR. Sequential ejaculate deposition of marked spermatozoa and SR screening showed that most spermatozoa in the SR arose from the fortuitous PSP-poor, first portion of the SRF fraction, escaping phagocytosis and replenishing the SR within 23 h. The SR-sperm numbers diminish gradually in relation to ovulation, spermatozoa. being continuously redistributed toward the upper isthmus. In vitro, only uncapacitated spermatozoa bind to epithelial explants, suggesting that the SR influences sperm capacitation. In vivo, most viable spermatozoa - usually harbored in the deep furrows in the pre- or peri-ovulatory SR during spontaneous standing estrus - are uncapacitated, but capacitation significantly increases after ovulation. Pre-/peri-ovulatory SR spermatozoa promptly capacitate in vitro when exposed to the effector bicarbonate, an influence that can be reversed by co-incubation with SR fluid or its component hyaluronan. Fluid collected from the ampullar segment (rich in bicarbonate) induces capacitation in vitro. In conclusion, the lack of massive sperm capacitation in the SR and the diverse individual response to capacitation shown by tubal spermatozoa would relate both to the insurance of full sperm viability before ovulation and the presence of spermatozoa at different stages of capacitation in the upper oviduct, thus maximizing the chances of normal fertilization. (C) 2004 Elsevier Inc. All rights reserved.
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